neovim

ex_getln.c (148992B)

---

// ex_getln.c: Functions for entering and editing an Ex command line.

#include <assert.h>
#include <inttypes.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "klib/kvec.h"
#include "nvim/api/extmark.h"
#include "nvim/api/private/defs.h"
#include "nvim/api/private/helpers.h"
#include "nvim/api/vim.h"
#include "nvim/ascii_defs.h"
#include "nvim/autocmd.h"
#include "nvim/autocmd_defs.h"
#include "nvim/buffer.h"
#include "nvim/buffer_defs.h"
#include "nvim/charset.h"
#include "nvim/clipboard.h"
#include "nvim/cmdexpand.h"
#include "nvim/cmdexpand_defs.h"
#include "nvim/cmdhist.h"
#include "nvim/cursor.h"
#include "nvim/digraph.h"
#include "nvim/drawscreen.h"
#include "nvim/edit.h"
#include "nvim/errors.h"
#include "nvim/eval.h"
#include "nvim/eval/typval.h"
#include "nvim/eval/vars.h"
#include "nvim/ex_cmds.h"
#include "nvim/ex_cmds_defs.h"
#include "nvim/ex_docmd.h"
#include "nvim/ex_eval.h"
#include "nvim/ex_getln.h"
#include "nvim/extmark.h"
#include "nvim/garray.h"
#include "nvim/garray_defs.h"
#include "nvim/getchar.h"
#include "nvim/gettext_defs.h"
#include "nvim/globals.h"
#include "nvim/highlight_defs.h"
#include "nvim/highlight_group.h"
#include "nvim/keycodes.h"
#include "nvim/macros_defs.h"
#include "nvim/map_defs.h"
#include "nvim/mapping.h"
#include "nvim/mark.h"
#include "nvim/mark_defs.h"
#include "nvim/mbyte.h"
#include "nvim/memline.h"
#include "nvim/memory.h"
#include "nvim/memory_defs.h"
#include "nvim/message.h"
#include "nvim/mouse.h"
#include "nvim/move.h"
#include "nvim/normal.h"
#include "nvim/ops.h"
#include "nvim/option.h"
#include "nvim/option_defs.h"
#include "nvim/option_vars.h"
#include "nvim/os/input.h"
#include "nvim/os/os.h"
#include "nvim/path.h"
#include "nvim/popupmenu.h"
#include "nvim/pos_defs.h"
#include "nvim/profile.h"
#include "nvim/regexp.h"
#include "nvim/regexp_defs.h"
#include "nvim/register.h"
#include "nvim/search.h"
#include "nvim/state.h"
#include "nvim/state_defs.h"
#include "nvim/strings.h"
#include "nvim/types_defs.h"
#include "nvim/ui.h"
#include "nvim/ui_defs.h"
#include "nvim/undo.h"
#include "nvim/undo_defs.h"
#include "nvim/usercmd.h"
#include "nvim/vim_defs.h"
#include "nvim/viml/parser/expressions.h"
#include "nvim/viml/parser/parser.h"
#include "nvim/viml/parser/parser_defs.h"
#include "nvim/window.h"

/// Last value of prompt_id, incremented when doing new prompt
static unsigned last_prompt_id = 0;

// Struct to store the viewstate during 'incsearch' highlighting and 'inccommand' preview.
typedef struct {
 colnr_T vs_curswant;
 colnr_T vs_leftcol;
 colnr_T vs_skipcol;
 linenr_T vs_topline;
 int vs_topfill;
 linenr_T vs_botline;
 int vs_empty_rows;
} viewstate_T;

// Struct to store the state of 'incsearch' highlighting.
typedef struct {
 pos_T search_start;   // where 'incsearch' starts searching
 pos_T save_cursor;
 handle_T winid;       // window where this state is valid
 viewstate_T init_viewstate;
 viewstate_T old_viewstate;
 pos_T match_start;
 pos_T match_end;
 bool did_incsearch;
 bool incsearch_postponed;
 optmagic_T magic_overruled_save;
} incsearch_state_T;

typedef struct {
 VimState state;
 int firstc;
 int count;
 int indent;
 int c;
 bool gotesc;                          // true when <ESC> just typed
 bool do_abbr;                         // when true check for abbr.
 char *lookfor;                        // string to match
 int lookforlen;
 int hiscnt;                           // current history line in use
 int save_hiscnt;                      // history line before attempting
                                       // to jump to next match
 int histype;                          // history type to be used
 incsearch_state_T is_state;
 bool did_wild_list;                   // did wild_list() recently
 int wim_index;                        // index in wim_flags[]
 int save_msg_scroll;
 int save_State;                       // remember State when called
 int prev_cmdpos;
 char *prev_cmdbuff;
 char *save_p_icm;
 bool skip_pum_redraw;
 bool some_key_typed;                  // one of the keys was typed
 // mouse drag and release events are ignored, unless they are
 // preceded with a mouse down event
 bool ignore_drag_release;
 bool break_ctrl_c;
 expand_T xpc;
 OptInt *b_im_ptr;
 buf_T *b_im_ptr_buf;  ///< buffer where b_im_ptr is valid
 int cmdline_type;
 bool event_cmdlineleavepre_triggered;
 bool did_hist_navigate;
} CommandLineState;

typedef struct {
 u_header_T *save_b_u_oldhead;
 u_header_T *save_b_u_newhead;
 u_header_T *save_b_u_curhead;
 int save_b_u_numhead;
 bool save_b_u_synced;
 int save_b_u_seq_last;
 int save_b_u_save_nr_last;
 int save_b_u_seq_cur;
 time_t save_b_u_time_cur;
 int save_b_u_save_nr_cur;
 char *save_b_u_line_ptr;
 linenr_T save_b_u_line_lnum;
 colnr_T save_b_u_line_colnr;
} CpUndoInfo;

typedef struct {
 buf_T *buf;
 OptInt save_b_p_ul;
 int save_b_p_ma;
 int save_b_changed;
 pos_T save_b_op_start;
 pos_T save_b_op_end;
 varnumber_T save_changedtick;
 CpUndoInfo undo_info;
} CpBufInfo;

typedef struct {
 win_T *win;
 pos_T save_w_cursor;
 viewstate_T save_viewstate;
 int save_w_p_cul;
 int save_w_p_cuc;
} CpWinInfo;

typedef struct {
 kvec_t(CpWinInfo) win_info;
 kvec_t(CpBufInfo) buf_info;
 bool save_hls;
 cmdmod_T save_cmdmod;
 garray_T save_view;
} CpInfo;

/// Return value when handling keys in command-line mode.
enum {
 CMDLINE_NOT_CHANGED = 1,
 CMDLINE_CHANGED     = 2,
 GOTO_NORMAL_MODE    = 3,
 PROCESS_NEXT_KEY    = 4,
};

/// The current cmdline_info.  It is initialized in getcmdline() and after that
/// used by other functions.  When invoking getcmdline() recursively it needs
/// to be saved with save_cmdline() and restored with restore_cmdline().
static CmdlineInfo ccline;

static int new_cmdpos;          // position set by set_cmdline_pos()

/// currently displayed block of context
static Array cmdline_block = ARRAY_DICT_INIT;

/// Flag for command_line_handle_key to ignore <C-c>
///
/// Used if it was received while processing highlight function in order for
/// user interrupting highlight function to not interrupt command-line.
static bool getln_interrupted_highlight = false;

static int cedit_key = -1;  ///< key value of 'cedit' option

#include "ex_getln.c.generated.h"

static handle_T cmdpreview_bufnr = 0;
static int cmdpreview_ns = 0;

static const char e_active_window_or_buffer_changed_or_deleted[]
 = N_("E199: Active window or buffer changed or deleted");

static void trigger_cmd_autocmd(int typechar, event_T evt)
{
 char typestr[2] = { (char)typechar, NUL };
 apply_autocmds(evt, typestr, typestr, false, curbuf);
}

static void save_viewstate(win_T *wp, viewstate_T *vs)
 FUNC_ATTR_NONNULL_ALL
{
 vs->vs_curswant = wp->w_curswant;
 vs->vs_leftcol = wp->w_leftcol;
 vs->vs_skipcol = wp->w_skipcol;
 vs->vs_topline = wp->w_topline;
 vs->vs_topfill = wp->w_topfill;
 vs->vs_botline = wp->w_botline;
 vs->vs_empty_rows = wp->w_empty_rows;
}

static void restore_viewstate(win_T *wp, viewstate_T *vs)
 FUNC_ATTR_NONNULL_ALL
{
 wp->w_curswant = vs->vs_curswant;
 wp->w_leftcol = vs->vs_leftcol;
 wp->w_skipcol = vs->vs_skipcol;
 wp->w_topline = vs->vs_topline;
 wp->w_topfill = vs->vs_topfill;
 wp->w_botline = vs->vs_botline;
 wp->w_empty_rows = vs->vs_empty_rows;
}

static void init_incsearch_state(incsearch_state_T *s)
{
 s->winid = curwin->handle;
 s->match_start = curwin->w_cursor;
 s->did_incsearch = false;
 s->incsearch_postponed = false;
 s->magic_overruled_save = magic_overruled;
 clearpos(&s->match_end);
 s->save_cursor = curwin->w_cursor;  // may be restored later
 s->search_start = curwin->w_cursor;
 save_viewstate(curwin, &s->init_viewstate);
 save_viewstate(curwin, &s->old_viewstate);
}

static void set_search_match(pos_T *t)
{
 // First move cursor to end of match, then to the start.  This
 // moves the whole match onto the screen when 'nowrap' is set.
 t->lnum += search_match_lines;
 t->col = search_match_endcol;
 if (t->lnum > curbuf->b_ml.ml_line_count) {
   t->lnum = curbuf->b_ml.ml_line_count;
   coladvance(curwin, MAXCOL);
 }
}

/// Parses the :[range]s/foo like commands and returns details needed for
/// incsearch and wildmenu completion.
/// Returns true if pattern is valid.
/// Sets skiplen, patlen, search_first_line, and search_last_line.
bool parse_pattern_and_range(pos_T *incsearch_start, int *search_delim, int *skiplen, int *patlen)
 FUNC_ATTR_NONNULL_ALL
{
 char *p;
 bool delim_optional = false;
 const char *dummy;
 magic_T magic = 0;

 *skiplen = 0;
 *patlen = ccline.cmdlen;

 // Default range
 search_first_line = 0;
 search_last_line = MAXLNUM;

 exarg_T ea = {
   .line1 = 1,
   .line2 = 1,
   .cmd = ccline.cmdbuff,
   .addr_type = ADDR_LINES,
 };

 cmdmod_T dummy_cmdmod;
 // Skip over command modifiers
 parse_command_modifiers(&ea, &dummy, &dummy_cmdmod, true);

 // Skip over the range to find the command.
 char *cmd = skip_range(ea.cmd, NULL);
 if (vim_strchr("sgvl", (uint8_t)(*cmd)) == NULL) {
   return false;
 }

 // Skip over command name to find pattern separator
 for (p = cmd; ASCII_ISALPHA(*p); p++) {}
 if (*skipwhite(p) == NUL) {
   return false;
 }

 if (strncmp(cmd, "substitute", (size_t)(p - cmd)) == 0
     || strncmp(cmd, "smagic", (size_t)(p - cmd)) == 0
     || strncmp(cmd, "snomagic", (size_t)MAX(p - cmd, 3)) == 0
     || strncmp(cmd, "vglobal", (size_t)(p - cmd)) == 0) {
   if (*cmd == 's' && cmd[1] == 'm') {
     magic_overruled = OPTION_MAGIC_ON;
   } else if (*cmd == 's' && cmd[1] == 'n') {
     magic_overruled = OPTION_MAGIC_OFF;
   }
 } else if (strncmp(cmd, "sort", (size_t)MAX(p - cmd, 3)) == 0
            || strncmp(cmd, "uniq", (size_t)MAX(p - cmd, 3)) == 0) {
   // skip over ! and flags
   if (*p == '!') {
     p = skipwhite(p + 1);
   }
   while (ASCII_ISALPHA(*(p = skipwhite(p)))) {
     p++;
   }
   if (*p == NUL) {
     return false;
   }
 } else if (strncmp(cmd, "vimgrep", (size_t)MAX(p - cmd, 3)) == 0
            || strncmp(cmd, "vimgrepadd", (size_t)MAX(p - cmd, 8)) == 0
            || strncmp(cmd, "lvimgrep", (size_t)MAX(p - cmd, 2)) == 0
            || strncmp(cmd, "lvimgrepadd", (size_t)MAX(p - cmd, 9)) == 0
            || strncmp(cmd, "global", (size_t)(p - cmd)) == 0) {
   // skip optional "!"
   if (*p == '!') {
     p++;
     if (*skipwhite(p) == NUL) {
       return false;
     }
   }
   if (*cmd != 'g') {
     delim_optional = true;
   }
 } else {
   return false;
 }

 p = skipwhite(p);
 int delim = (delim_optional && vim_isIDc((uint8_t)(*p))) ? ' ' : *p++;
 *search_delim = delim;

 char *end = skip_regexp_ex(p, delim, magic_isset(), NULL, NULL, &magic);
 bool use_last_pat = end == p && *end == delim;

 if (end == p && !use_last_pat) {
   return false;
 }

 // Skip if the pattern matches everything (e.g., for 'hlsearch')
 if (!use_last_pat) {
   char c = *end;
   *end = NUL;
   bool empty = empty_pattern_magic(p, (size_t)(end - p), magic);
   *end = c;
   if (empty) {
     return false;
   }
 }

 // Found a non-empty pattern or //
 *skiplen = (int)(p - ccline.cmdbuff);
 *patlen = (int)(end - p);

 // Parse the address range
 pos_T save_cursor = curwin->w_cursor;
 curwin->w_cursor = *incsearch_start;

 parse_cmd_address(&ea, &dummy, true);

 if (ea.addr_count > 0) {
   // Allow for reverse match.
   search_first_line = MIN(ea.line2, ea.line1);
   search_last_line = MAX(ea.line2, ea.line1);
 } else if (cmd[0] == 's' && cmd[1] != 'o') {
   // :s defaults to the current line
   search_first_line = search_last_line = curwin->w_cursor.lnum;
 }

 curwin->w_cursor = save_cursor;
 return true;
}

/// Return true when 'incsearch' highlighting is to be done.
/// Sets search_first_line and search_last_line to the address range.
/// May change the last search pattern.
static bool do_incsearch_highlighting(int firstc, int *search_delim, incsearch_state_T *is_state,
                                     int *skiplen, int *patlen)
{
 bool retval = false;

 *skiplen = 0;
 *patlen = ccline.cmdlen;

 if (!p_is || cmd_silent) {
   return false;
 }

 // By default search all lines
 search_first_line = 0;
 search_last_line = MAXLNUM;

 if (firstc == '/' || firstc == '?') {
   *search_delim = firstc;
   return true;
 }

 if (firstc != ':') {
   return false;
 }

 emsg_off++;
 retval = parse_pattern_and_range(&is_state->search_start, search_delim,
                                  skiplen, patlen);
 emsg_off--;

 return retval;
}

// May do 'incsearch' highlighting if desired.
static void may_do_incsearch_highlighting(int firstc, int count, incsearch_state_T *s)
{
 int skiplen, patlen;
 int search_delim;

 // Parsing range may already set the last search pattern.
 // NOTE: must call restore_last_search_pattern() before returning!
 save_last_search_pattern();

 if (!do_incsearch_highlighting(firstc, &search_delim, s, &skiplen, &patlen)) {
   restore_last_search_pattern();
   finish_incsearch_highlighting(false, s, true);
   return;
 }

 // if there is a character waiting, search and redraw later
 if (char_avail()) {
   restore_last_search_pattern();
   s->incsearch_postponed = true;
   return;
 }
 s->incsearch_postponed = false;

 // Use the previous pattern for ":s//".
 char next_char = ccline.cmdbuff[skiplen + patlen];
 bool use_last_pat = patlen == 0 && skiplen > 0
                     && ccline.cmdbuff[skiplen - 1] == next_char;

 if (patlen != 0 || use_last_pat) {
   ui_busy_start();
   ui_flush();
 }

 if (search_first_line == 0) {
   // start at the original cursor position
   curwin->w_cursor = s->search_start;
 } else if (search_first_line > curbuf->b_ml.ml_line_count) {
   // start after the last line
   curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
   curwin->w_cursor.col = MAXCOL;
 } else {
   // start at the first line in the range
   curwin->w_cursor.lnum = search_first_line;
   curwin->w_cursor.col = 0;
 }

 int found = 0;  // do_search() result

 if (patlen != 0 || use_last_pat) {
   int search_flags = SEARCH_OPT + SEARCH_NOOF + SEARCH_PEEK;
   if (!p_hls) {
     search_flags += SEARCH_KEEP;
   }
   if (search_first_line != 0) {
     search_flags += SEARCH_START;
   }
   // Set the time limit to half a second.
   proftime_T tm = profile_setlimit(500);
   searchit_arg_T sia = { .sa_tm = &tm };
   ccline.cmdbuff[skiplen + patlen] = NUL;
   emsg_off++;            // So it doesn't beep if bad expr
   found = do_search(NULL, firstc == ':' ? '/' : firstc, search_delim,
                     ccline.cmdbuff + skiplen, (size_t)patlen, count,
                     search_flags, &sia);
   emsg_off--;
   ccline.cmdbuff[skiplen + patlen] = next_char;
   if (curwin->w_cursor.lnum < search_first_line
       || curwin->w_cursor.lnum > search_last_line) {
     // match outside of address range
     found = 0;
     curwin->w_cursor = s->search_start;
   }

   // if interrupted while searching, behave like it failed
   if (got_int) {
     vpeekc();               // remove <C-C> from input stream
     got_int = false;              // don't abandon the command line
     found = 0;
   } else if (char_avail()) {
     // cancelled searching because a char was typed
     s->incsearch_postponed = true;
   }
   ui_busy_stop();
 } else {
   set_no_hlsearch(true);  // turn off previous highlight
   redraw_all_later(UPD_SOME_VALID);
 }

 highlight_match = found != 0;  // add or remove search match position

 // first restore the old curwin values, so the screen is
 // positioned in the same way as the actual search command
 restore_viewstate(curwin, &s->old_viewstate);
 changed_cline_bef_curs(curwin);
 update_topline(curwin);

 pos_T end_pos = curwin->w_cursor;
 if (found != 0) {
   s->match_start = curwin->w_cursor;
   set_search_match(&curwin->w_cursor);
   validate_cursor(curwin);
   s->match_end = curwin->w_cursor;
   curwin->w_cursor = end_pos;
   end_pos = s->match_end;
 }

 // Disable 'hlsearch' highlighting if the pattern matches
 // everything. Avoids a flash when typing "foo\|".
 if (!use_last_pat) {
   next_char = ccline.cmdbuff[skiplen + patlen];
   ccline.cmdbuff[skiplen + patlen] = NUL;
   if (empty_pattern(ccline.cmdbuff + skiplen, (size_t)patlen, search_delim)
       && !no_hlsearch) {
     redraw_all_later(UPD_SOME_VALID);
     set_no_hlsearch(true);
   }
   ccline.cmdbuff[skiplen + patlen] = next_char;
 }

 validate_cursor(curwin);

 // May redraw the status line to show the cursor position.
 if (p_ru && (curwin->w_status_height > 0 || global_stl_height() > 0)) {
   curwin->w_redr_status = true;
 }

 redraw_later(curwin, UPD_SOME_VALID);
 update_screen();
 highlight_match = false;
 restore_last_search_pattern();

 // Leave it at the end to make CTRL-R CTRL-W work.  But not when beyond the
 // end of the pattern, e.g. for ":s/pat/".
 if (ccline.cmdbuff[skiplen + patlen] != NUL) {
   curwin->w_cursor = s->search_start;
 } else if (found != 0) {
   curwin->w_cursor = end_pos;
   curwin->w_valid_cursor = end_pos;  // mark as valid for cmdline_show redraw
 }

 msg_starthere();
 redrawcmdline();
 s->did_incsearch = true;
}

// When CTRL-L typed: add character from the match to the pattern.
// May set "*c" to the added character.
// Return OK when calling command_line_not_changed.
static int may_add_char_to_search(int firstc, int *c, incsearch_state_T *s)
 FUNC_ATTR_NONNULL_ALL
{
 int skiplen, patlen;
 int search_delim;

 // Parsing range may already set the last search pattern.
 // NOTE: must call restore_last_search_pattern() before returning!
 save_last_search_pattern();

 // Add a character from under the cursor for 'incsearch'
 if (!do_incsearch_highlighting(firstc, &search_delim, s, &skiplen,
                                &patlen)) {
   restore_last_search_pattern();
   return FAIL;
 }
 restore_last_search_pattern();

 if (s->did_incsearch) {
   curwin->w_cursor = s->match_end;
   *c = gchar_cursor();
   if (*c != NUL) {
     // If 'ignorecase' and 'smartcase' are set and the
     // command line has no uppercase characters, convert
     // the character to lowercase
     if (p_ic && p_scs
         && !pat_has_uppercase(ccline.cmdbuff + skiplen)) {
       *c = mb_tolower(*c);
     }
     if (*c == search_delim
         || vim_strchr((magic_isset() ? "\\~^$.*[" : "\\^$"), *c) != NULL) {
       // put a backslash before special characters
       stuffcharReadbuff(*c);
       *c = '\\';
     }
     // add any composing characters
     if (utf_char2len(*c) != utfc_ptr2len(get_cursor_pos_ptr())) {
       const int save_c = *c;
       while (utf_char2len(*c) != utfc_ptr2len(get_cursor_pos_ptr())) {
         curwin->w_cursor.col += utf_char2len(*c);
         *c = gchar_cursor();
         stuffcharReadbuff(*c);
       }
       *c = save_c;
     }
     return FAIL;
   }
 }
 return OK;
}

static void finish_incsearch_highlighting(bool gotesc, incsearch_state_T *s,
                                         bool call_update_screen)
{
 if (!s->did_incsearch) {
   return;
 }

 s->did_incsearch = false;
 if (gotesc) {
   curwin->w_cursor = s->save_cursor;
 } else {
   if (!equalpos(s->save_cursor, s->search_start)) {
     // put the '" mark at the original position
     curwin->w_cursor = s->save_cursor;
     setpcmark();
   }
   curwin->w_cursor = s->search_start;
 }
 restore_viewstate(curwin, &s->old_viewstate);
 highlight_match = false;

 // by default search all lines
 search_first_line = 0;
 search_last_line = MAXLNUM;

 magic_overruled = s->magic_overruled_save;

 validate_cursor(curwin);          // needed for TAB
 status_redraw_all();
 redraw_all_later(UPD_SOME_VALID);
 if (call_update_screen) {
   update_screen();
 }
}

/// Initialize the current command-line info.
static void init_ccline(int firstc, int indent)
{
 ccline.overstrike = false;                // always start in insert mode

 assert(indent >= 0);

 // set some variables for redrawcmd()
 ccline.cmdfirstc = (firstc == '@' ? 0 : firstc);
 ccline.cmdindent = (firstc > 0 ? indent : 0);

 // alloc initial ccline.cmdbuff
 alloc_cmdbuff(indent + 50);
 ccline.cmdlen = ccline.cmdpos = 0;
 ccline.cmdbuff[0] = NUL;

 ccline.last_colors = (ColoredCmdline){ .cmdbuff = NULL,
                                        .colors = KV_INITIAL_VALUE };
 sb_text_start_cmdline();

 // autoindent for :insert and :append
 if (firstc <= 0) {
   memset(ccline.cmdbuff, ' ', (size_t)indent);
   ccline.cmdbuff[indent] = NUL;
   ccline.cmdpos = indent;
   ccline.cmdspos = indent;
   ccline.cmdlen = indent;
 }
}

static void ui_ext_cmdline_hide(bool abort)
{
 if (ui_has(kUICmdline)) {
   cmdline_was_last_drawn = false;
   ccline.redraw_state = kCmdRedrawNone;
   ui_call_cmdline_hide(ccline.level, abort);
 }
}

/// Internal entry point for cmdline mode.
///
/// @param count  only used for incremental search
/// @param indent  indent for inside conditionals
/// @param clear_ccline  clear ccline first
static uint8_t *command_line_enter(int firstc, int count, int indent, bool clear_ccline)
{
 // can be invoked recursively, identify each level
 static int cmdline_level = 0;
 cmdline_level++;

 bool save_cmdpreview = cmdpreview;
 cmdpreview = false;
 CommandLineState state = {
   .firstc = firstc,
   .count = count,
   .indent = indent,
   .save_msg_scroll = msg_scroll,
   .save_State = State,
   .prev_cmdpos = -1,
   .ignore_drag_release = true,
 };
 CommandLineState *s = &state;
 s->save_p_icm = xstrdup(p_icm);
 init_incsearch_state(&s->is_state);
 CmdlineInfo save_ccline;
 bool did_save_ccline = false;

 if (ccline.cmdbuff != NULL) {
   // Currently ccline can never be in use if clear_ccline is false.
   // Some changes will be needed if this is no longer the case.
   assert(clear_ccline);
   // Being called recursively.  Since ccline is global, we need to save
   // the current buffer and restore it when returning.
   save_cmdline(&save_ccline);
   did_save_ccline = true;
 } else if (clear_ccline) {
   CLEAR_FIELD(ccline);
 }

 if (s->firstc == -1) {
   s->firstc = NUL;
   s->break_ctrl_c = true;
 }

 init_ccline(s->firstc, s->indent);
 assert(ccline.cmdbuff != NULL);
 ccline.prompt_id = last_prompt_id++;
 ccline.level = cmdline_level;

 if (cmdline_level == 50) {
   // Somehow got into a loop recursively calling getcmdline(), bail out.
   emsg(_(e_command_too_recursive));
   goto theend;
 }

 ExpandInit(&s->xpc);
 ccline.xpc = &s->xpc;
 clear_cmdline_orig();

 cmdmsg_rl = (curwin->w_p_rl && *curwin->w_p_rlc == 's'
              && (s->firstc == '/' || s->firstc == '?'));

 msg_grid_validate();

 redir_off = true;             // don't redirect the typed command
 if (!cmd_silent) {
   gotocmdline(true);
   redrawcmdprompt();          // draw prompt or indent
   ccline.cmdspos = cmd_startcol();
 }
 s->xpc.xp_context = EXPAND_NOTHING;
 s->xpc.xp_backslash = XP_BS_NONE;
#ifndef BACKSLASH_IN_FILENAME
 s->xpc.xp_shell = false;
#endif

 if (ccline.input_fn) {
   s->xpc.xp_context = ccline.xp_context;
   s->xpc.xp_pattern = ccline.cmdbuff;
   s->xpc.xp_arg = ccline.xp_arg;
 }

 // Avoid scrolling when called by a recursive do_cmdline(), e.g. when
 // doing ":@0" when register 0 doesn't contain a CR.
 msg_scroll = false;

 State = MODE_CMDLINE;

 if (s->firstc == '/' || s->firstc == '?' || s->firstc == '@') {
   // Use ":lmap" mappings for search pattern and input().
   if (curbuf->b_p_imsearch == B_IMODE_USE_INSERT) {
     s->b_im_ptr = &curbuf->b_p_iminsert;
   } else {
     s->b_im_ptr = &curbuf->b_p_imsearch;
   }
   s->b_im_ptr_buf = curbuf;
   if (*s->b_im_ptr == B_IMODE_LMAP) {
     State |= MODE_LANGMAP;
   }
 }

 setmouse();

 s->cmdline_type = firstc > 0 ? firstc : '-';
 Error err = ERROR_INIT;
 char firstcbuf[2];
 firstcbuf[0] = (char)s->cmdline_type;
 firstcbuf[1] = 0;

 if (has_event(EVENT_CMDLINEENTER)) {
   save_v_event_T save_v_event;
   dict_T *dict = get_v_event(&save_v_event);

   // set v:event to a dictionary with information about the commandline
   tv_dict_add_str(dict, S_LEN("cmdtype"), firstcbuf);
   tv_dict_add_nr(dict, S_LEN("cmdlevel"), ccline.level);
   tv_dict_set_keys_readonly(dict);
   TRY_WRAP(&err, {
     apply_autocmds(EVENT_CMDLINEENTER, firstcbuf, firstcbuf, false, curbuf);
     restore_v_event(dict, &save_v_event);
   });

   if (ERROR_SET(&err)) {
     if (!ui_has(kUIMessages)) {
       msg_putchar('\n');
     }
     msg_scroll = true;
     msg_puts_hl(err.msg, HLF_E, true);
     api_clear_error(&err);
     redrawcmd();
   }
   err = ERROR_INIT;
 }
 may_trigger_modechanged();

 init_history();
 s->hiscnt = get_hislen();  // set hiscnt to impossible history value
 s->histype = hist_char2type(s->firstc);
 do_digraph(-1);                       // init digraph typeahead

 // If something above caused an error, reset the flags, we do want to type
 // and execute commands. Display may be messed up a bit.
 if (did_emsg) {
   redrawcmd();
 }

 // Redraw the statusline in case it uses the current mode using the mode()
 // function.
 if (!cmd_silent && !exmode_active) {
   bool found_one = false;

   FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
     if (*p_stl != NUL || *wp->w_p_stl != NUL || *p_wbr != NUL || *wp->w_p_wbr != NUL) {
       wp->w_redr_status = true;
       found_one = true;
     }
   }

   if (*p_tal != NUL) {
     redraw_tabline = true;
     found_one = true;
   }

   if (redraw_custom_title_later()) {
     found_one = true;
   }

   if (found_one) {
     redraw_statuslines();
   }
 }

 did_emsg = false;
 got_int = false;
 s->state.check = command_line_check;
 s->state.execute = command_line_execute;

 state_enter(&s->state);

 // Trigger CmdlineLeavePre autocommands if not already triggered.
 if (!s->event_cmdlineleavepre_triggered) {
   set_vim_var_char(s->c);  // Set v:char
   trigger_cmd_autocmd(s->cmdline_type, EVENT_CMDLINELEAVEPRE);
 }

 if (has_event(EVENT_CMDLINELEAVE)) {
   save_v_event_T save_v_event;
   dict_T *dict = get_v_event(&save_v_event);

   tv_dict_add_str(dict, S_LEN("cmdtype"), firstcbuf);
   tv_dict_add_nr(dict, S_LEN("cmdlevel"), ccline.level);
   tv_dict_set_keys_readonly(dict);
   // not readonly:
   tv_dict_add_bool(dict, S_LEN("abort"),
                    s->gotesc ? kBoolVarTrue : kBoolVarFalse);
   set_vim_var_char(s->c);  // Set v:char
   TRY_WRAP(&err, {
     apply_autocmds(EVENT_CMDLINELEAVE, firstcbuf, firstcbuf, false, curbuf);
     // error printed below, to avoid redraw issues
   });
   if (tv_dict_get_number(dict, "abort") != 0) {
     s->gotesc = true;
   }
   restore_v_event(dict, &save_v_event);
 }

 cmdmsg_rl = false;

 // We could have reached here without having a chance to clean up wild menu
 // if certain special keys like <Esc> or <C-\> were used as wildchar. Make
 // sure to still clean up to avoid memory corruption.
 if (cmdline_pum_active()) {
   cmdline_pum_remove(false);
 } else {
   // A previous cmdline_pum_remove() may have deferred redraw.
   pum_check_clear();
 }
 wildmenu_cleanup(&ccline);
 s->did_wild_list = false;
 s->wim_index = 0;

 ExpandCleanup(&s->xpc);
 ccline.xpc = NULL;
 clear_cmdline_orig();

 finish_incsearch_highlighting(s->gotesc, &s->is_state, false);

 if (ccline.cmdbuff != NULL) {
   // Put line in history buffer (":" and "=" only when it was typed).
   if (s->histype != HIST_INVALID
       && ccline.cmdlen
       && s->firstc != NUL
       && (s->some_key_typed || s->histype == HIST_SEARCH)) {
     add_to_history(s->histype, ccline.cmdbuff, (size_t)ccline.cmdlen, true,
                    s->histype == HIST_SEARCH ? s->firstc : NUL);
     if (s->firstc == ':') {
       xfree(new_last_cmdline);
       new_last_cmdline = xstrnsave(ccline.cmdbuff, (size_t)ccline.cmdlen);
     }
   }

   if (s->gotesc) {
     abandon_cmdline();
   }
 }

 // If the screen was shifted up, redraw the whole screen (later).
 // If the line is too long, clear it, so ruler and shown command do
 // not get printed in the middle of it.
 msg_check();
 if (p_ch == 0 && !ui_has(kUIMessages)) {
   set_must_redraw(UPD_VALID);
 }
 msg_scroll = s->save_msg_scroll;
 redir_off = false;

 if (ERROR_SET(&err)) {
   if (!ui_has(kUIMessages)) {
     msg_putchar('\n');
   }
   emsg(err.msg);
   did_emsg = false;
   api_clear_error(&err);
 }

 // When the command line was typed, no need for a wait-return prompt.
 if (s->some_key_typed && !ERROR_SET(&err)) {
   need_wait_return = false;
 }

 set_option_direct(kOptInccommand, CSTR_AS_OPTVAL(s->save_p_icm), 0, SID_NONE);
 State = s->save_State;
 if (cmdpreview != save_cmdpreview) {
   cmdpreview = save_cmdpreview;  // restore preview state
   redraw_all_later(UPD_SOME_VALID);
 }
 may_trigger_modechanged();
 setmouse();
 sb_text_end_cmdline();

theend:
 xfree(s->save_p_icm);
 xfree(ccline.last_colors.cmdbuff);
 kv_destroy(ccline.last_colors.colors);

 char *p = ccline.cmdbuff;

 if (ui_has(kUICmdline)) {
   if (exmode_active) {
     ui_ext_cmdline_block_append(0, p);
   }
   ui_ext_cmdline_hide(s->gotesc);
 }
 if (!cmd_silent) {
   redraw_custom_title_later();
   status_redraw_all();  // redraw to show mode change
 }

 cmdline_level--;

 if (did_save_ccline) {
   restore_cmdline(&save_ccline);
 } else {
   ccline.cmdbuff = NULL;
 }

 xfree(s->prev_cmdbuff);
 return (uint8_t *)p;
}

static int command_line_check(VimState *state)
{
 CommandLineState *s = (CommandLineState *)state;

 s->prev_cmdpos = ccline.cmdpos;
 XFREE_CLEAR(s->prev_cmdbuff);

 redir_off = true;        // Don't redirect the typed command.
 // Repeated, because a ":redir" inside
 // completion may switch it on.
 quit_more = false;       // reset after CTRL-D which had a more-prompt

 did_emsg = false;        // There can't really be a reason why an error
                          // that occurs while typing a command should
                          // cause the command not to be executed.

 if (ex_normal_busy == 0 && stuff_empty() && typebuf.tb_len == 0) {
   // There is no pending input from sources other than user input, so
   // Vim is going to wait for the user to type a key.  Consider the
   // command line typed even if next key will trigger a mapping.
   s->some_key_typed = true;
 }

 // Trigger SafeState if nothing is pending.
 may_trigger_safestate(s->xpc.xp_numfiles <= 0);

 if (ccline.cmdbuff != NULL) {
   s->prev_cmdbuff = xstrdup(ccline.cmdbuff);
 }

 // Defer screen update to avoid pum flicker during wildtrigger()
 if (s->c == K_WILD && s->firstc != '@') {
   s->skip_pum_redraw = true;
 }

 cursorcmd();             // set the cursor on the right spot
 ui_cursor_shape();
 return 1;
}

/// Handle CTRL-\ pressed in Command-line mode:
/// - CTRL-\ CTRL-N or CTRL-\ CTRL-G goes to Normal mode.
/// - CTRL-\ e prompts for an expression.
static int command_line_handle_ctrl_bsl(CommandLineState *s)
{
 no_mapping++;
 allow_keys++;
 s->c = plain_vgetc();
 no_mapping--;
 allow_keys--;

 // CTRL-\ e doesn't work when obtaining an expression, unless it
 // is in a mapping.
 if (s->c != Ctrl_N
     && s->c != Ctrl_G
     && (s->c != 'e'
         || (ccline.cmdfirstc == '=' && KeyTyped)
         || cmdline_star > 0)) {
   vungetc(s->c);
   return PROCESS_NEXT_KEY;
 }

 if (s->c == 'e') {
   // Replace the command line with the result of an expression.
   // This will call getcmdline() recursively in get_expr_register().
   if (ccline.cmdpos == ccline.cmdlen) {
     new_cmdpos = 99999;           // keep it at the end
   } else {
     new_cmdpos = ccline.cmdpos;
   }

   s->c = get_expr_register();
   if (s->c == '=') {
     // Evaluate the expression.  Set "textlock" to avoid nasty things
     // like going to another buffer.
     textlock++;
     char *p = get_expr_line();
     textlock--;

     if (p != NULL) {
       int len = (int)strlen(p);
       realloc_cmdbuff(len + 1);
       ccline.cmdlen = len;
       STRCPY(ccline.cmdbuff, p);
       xfree(p);

       // Restore the cursor or use the position set with
       // set_cmdline_pos().
       ccline.cmdpos = MIN(ccline.cmdlen, new_cmdpos);

       KeyTyped = false;                 // Don't do p_wc completion.
       redrawcmd();
       return CMDLINE_CHANGED;
     }
   }
   beep_flush();
   got_int = false;                // don't abandon the command line
   did_emsg = false;
   emsg_on_display = false;
   redrawcmd();
   return CMDLINE_NOT_CHANGED;
 }

 s->gotesc = true;  // will free ccline.cmdbuff after putting it in history
 return GOTO_NORMAL_MODE;
}

/// Completion for 'wildchar' or 'wildcharm' key.
/// - hitting <ESC> twice means: abandon command line.
/// - wildcard expansion is only done when the 'wildchar' key is really
///   typed, not when it comes from a macro
/// @return  CMDLINE_CHANGED if command line is changed or CMDLINE_NOT_CHANGED.
static int command_line_wildchar_complete(CommandLineState *s)
{
 int res;
 int options = WILD_NO_BEEP;
 bool escape = s->firstc != '@';
 bool redraw_if_menu_empty = s->c == K_WILD;
 bool wim_noselect = p_wmnu && (wim_flags[0] & kOptWimFlagNoselect) != 0;

 if (wim_flags[s->wim_index] & kOptWimFlagLastused) {
   options |= WILD_BUFLASTUSED;
 }
 if (s->xpc.xp_numfiles > 0) {       // typed p_wc at least twice
   // If "list" is present, list matches unless already listed
   if (s->xpc.xp_numfiles > 1
       && !s->did_wild_list
       && (wim_flags[s->wim_index] & kOptWimFlagList)) {
     showmatches(&s->xpc, false, true, wim_noselect);
     redrawcmd();
     s->did_wild_list = true;
   }
   if (wim_flags[s->wim_index] & kOptWimFlagLongest) {
     res = nextwild(&s->xpc, WILD_LONGEST, options, escape);
   } else if (wim_flags[s->wim_index] & kOptWimFlagFull) {
     res = nextwild(&s->xpc, WILD_NEXT, options, escape);
   } else {
     res = OK;                 // don't insert 'wildchar' now
   }
 } else {                    // typed p_wc first time
   bool wim_longest = (wim_flags[0] & kOptWimFlagLongest);
   bool wim_list = (wim_flags[0] & kOptWimFlagList);
   bool wim_full = (wim_flags[0] & kOptWimFlagFull);

   s->wim_index = 0;
   if (s->c == p_wc || s->c == p_wcm || s->c == K_WILD || s->c == Ctrl_Z) {
     options |= WILD_MAY_EXPAND_PATTERN;
     if (s->c == K_WILD) {
       options |= WILD_FUNC_TRIGGER;
     }
     s->xpc.xp_pre_incsearch_pos = s->is_state.search_start;
   }
   int cmdpos_before = ccline.cmdpos;

   // if 'wildmode' first contains "longest", get longest
   // common part
   if (wim_longest) {
     res = nextwild(&s->xpc, WILD_LONGEST, options, escape);
   } else {
     if (wim_noselect || wim_list) {
       options |= WILD_NOSELECT;
     }
     res = nextwild(&s->xpc, WILD_EXPAND_KEEP, options, escape);
   }

   // Remove popup menu if no completion items are available
   if (redraw_if_menu_empty && s->xpc.xp_numfiles <= 0) {
     pum_check_clear();
   }

   // if interrupted while completing, behave like it failed
   if (got_int) {
     vpeekc();               // remove <C-C> from input stream
     got_int = false;              // don't abandon the command line
     ExpandOne(&s->xpc, NULL, NULL, 0, WILD_FREE);
     s->xpc.xp_context = EXPAND_NOTHING;
     return CMDLINE_CHANGED;
   }

   // Display matches
   if (res == OK && s->xpc.xp_numfiles > (wim_noselect ? 0 : 1)) {
     if (wim_longest) {
       bool found_longest_prefix = (ccline.cmdpos != cmdpos_before);
       if (wim_list || (p_wmnu && wim_full)) {
         showmatches(&s->xpc, p_wmnu, wim_list, true);
       } else if (!found_longest_prefix) {
         bool wim_list_next = (wim_flags[1] & kOptWimFlagList);
         bool wim_full_next = (wim_flags[1] & kOptWimFlagFull);
         bool wim_noselect_next = (wim_flags[1] & kOptWimFlagNoselect);
         if (wim_list_next || (p_wmnu && (wim_full_next || wim_noselect_next))) {
           if (wim_full_next && !wim_noselect_next) {
             nextwild(&s->xpc, WILD_NEXT, options, escape);
           } else {
             showmatches(&s->xpc, p_wmnu, wim_list_next, wim_noselect_next);
           }
           if (wim_list_next) {
             s->did_wild_list = true;
           }
         }
       }
     } else {
       if (wim_list || (p_wmnu && (wim_full || wim_noselect))) {
         showmatches(&s->xpc, p_wmnu, wim_list, wim_noselect);
       } else {
         vim_beep(kOptBoFlagWildmode);
       }
     }

     redrawcmd();
     if (wim_list) {
       s->did_wild_list = true;
     }
   } else if (s->xpc.xp_numfiles == -1) {
     s->xpc.xp_context = EXPAND_NOTHING;
   }
 }

 if (s->wim_index < 3) {
   s->wim_index++;
 }

 if (s->c == ESC) {
   s->gotesc = true;
 }

 return (res == OK) ? CMDLINE_CHANGED : CMDLINE_NOT_CHANGED;
}

static void command_line_end_wildmenu(CommandLineState *s, bool key_is_wc)
{
 if (cmdline_pum_active()) {
   s->skip_pum_redraw = (s->skip_pum_redraw && !key_is_wc
                         && !ascii_iswhite(s->c)
                         && (vim_isprintc(s->c)
                             || s->c == K_BS || s->c == Ctrl_H || s->c == K_DEL
                             || s->c == K_KDEL || s->c == Ctrl_W || s->c == Ctrl_U));
   cmdline_pum_remove(s->skip_pum_redraw);
 }
 if (s->xpc.xp_numfiles != -1) {
   ExpandOne(&s->xpc, NULL, NULL, 0, WILD_FREE);
 }
 s->did_wild_list = false;
 if (!p_wmnu || (s->c != K_UP && s->c != K_DOWN)) {
   s->xpc.xp_context = EXPAND_NOTHING;
 }
 s->wim_index = 0;
 wildmenu_cleanup(&ccline);
}

static int command_line_execute(VimState *state, int key)
{
 if (key == K_IGNORE || key == K_NOP) {
   return -1;  // get another key
 }

 disptick_T display_tick_saved = display_tick;
 CommandLineState *s = (CommandLineState *)state;
 s->c = key;

 // Skip wildmenu during history navigation via Up/Down keys
 if (s->c == K_WILD && s->did_hist_navigate) {
   s->did_hist_navigate = false;
   return 1;
 }

 if (s->c == K_EVENT || s->c == K_COMMAND || s->c == K_LUA) {
   if (s->c == K_EVENT) {
     state_handle_k_event();
   } else if (s->c == K_COMMAND) {
     do_cmdline(NULL, getcmdkeycmd, NULL, DOCMD_NOWAIT);
   } else {
     map_execute_lua(false, false);
   }
   // If the window changed incremental search state is not valid.
   if (s->is_state.winid != curwin->handle) {
     init_incsearch_state(&s->is_state);
   }
   // Re-apply 'incsearch' highlighting in case it was cleared.
   if (display_tick > display_tick_saved && s->is_state.did_incsearch) {
     may_do_incsearch_highlighting(s->firstc, s->count, &s->is_state);
   }

   // nvim_select_popupmenu_item() can be called from the handling of
   // K_EVENT, K_COMMAND, or K_LUA.
   if (pum_want.active) {
     if (cmdline_pum_active()) {
       nextwild(&s->xpc, WILD_PUM_WANT, 0, s->firstc != '@');
       if (pum_want.finish) {
         nextwild(&s->xpc, WILD_APPLY, WILD_NO_BEEP, s->firstc != '@');
         command_line_end_wildmenu(s, false);
       }
     }
     pum_want.active = false;
   }

   if (!cmdline_was_last_drawn) {
     redrawcmdline();
   }
   return 1;
 }

 if (KeyTyped) {
   s->some_key_typed = true;

   if (cmdmsg_rl && !KeyStuffed) {
     // Invert horizontal movements and operations.  Only when
     // typed by the user directly, not when the result of a
     // mapping.
     switch (s->c) {
     case K_RIGHT:
       s->c = K_LEFT; break;
     case K_S_RIGHT:
       s->c = K_S_LEFT; break;
     case K_C_RIGHT:
       s->c = K_C_LEFT; break;
     case K_LEFT:
       s->c = K_RIGHT; break;
     case K_S_LEFT:
       s->c = K_S_RIGHT; break;
     case K_C_LEFT:
       s->c = K_C_RIGHT; break;
     }
   }
 }

 // Ignore got_int when CTRL-C was typed here.
 // Don't ignore it in :global, we really need to break then, e.g., for
 // ":g/pat/normal /pat" (without the <CR>).
 // Don't ignore it for the input() function.
 if ((s->c == Ctrl_C)
     && s->firstc != '@'
     // do clear got_int in Ex mode to avoid infinite Ctrl-C loop
     && (!s->break_ctrl_c || exmode_active)
     && !global_busy) {
   got_int = false;
 }

 // free old command line when finished moving around in the history
 // list
 if (s->lookfor != NULL
     && s->c != K_S_DOWN && s->c != K_S_UP
     && s->c != K_DOWN && s->c != K_UP
     && s->c != K_PAGEDOWN && s->c != K_PAGEUP
     && s->c != K_KPAGEDOWN && s->c != K_KPAGEUP
     && s->c != K_LEFT && s->c != K_RIGHT
     && (s->xpc.xp_numfiles > 0 || (s->c != Ctrl_P && s->c != Ctrl_N))) {
   XFREE_CLEAR(s->lookfor);
   s->lookforlen = 0;
 }

 // When there are matching completions to select <S-Tab> works like
 // CTRL-P (unless 'wc' is <S-Tab>).
 if (s->c != p_wc && s->c == K_S_TAB && s->xpc.xp_numfiles > 0) {
   s->c = Ctrl_P;
 }

 if (p_wmnu) {
   s->c = wildmenu_translate_key(&ccline, s->c, &s->xpc, s->did_wild_list);
 }

 int wild_type = 0;
 const bool key_is_wc = (s->c == p_wc && KeyTyped) || s->c == p_wcm;
 if ((cmdline_pum_active() || wild_menu_showing || s->did_wild_list)
     && !key_is_wc && s->xpc.xp_numfiles > 0) {
   // Ctrl-Y: Accept the current selection and close the popup menu.
   // Ctrl-E: cancel the cmdline popup menu and return the original text.
   if (s->c == Ctrl_E || s->c == Ctrl_Y) {
     wild_type = (s->c == Ctrl_E) ? WILD_CANCEL : WILD_APPLY;
     nextwild(&s->xpc, wild_type, WILD_NO_BEEP, s->firstc != '@');
   }
 }

 // Trigger CmdlineLeavePre autocommand
 if ((KeyTyped && (s->c == '\n' || s->c == '\r' || s->c == K_KENTER || s->c == ESC))
     || s->c == Ctrl_C) {
   set_vim_var_char(s->c);  // Set v:char
   trigger_cmd_autocmd(s->cmdline_type, EVENT_CMDLINELEAVEPRE);
   s->event_cmdlineleavepre_triggered = true;
   if ((s->c == ESC || s->c == Ctrl_C) && (wim_flags[0] & kOptWimFlagList)) {
     set_no_hlsearch(true);
   }
 }

 // The wildmenu is cleared if the pressed key is not used for
 // navigating the wild menu (i.e. the key is not 'wildchar' or
 // 'wildcharm' or Ctrl-N or Ctrl-P or Ctrl-A or Ctrl-L).
 // If the popup menu is displayed, then PageDown and PageUp keys are
 // also used to navigate the menu.
 bool end_wildmenu = (!key_is_wc && s->c != Ctrl_Z
                      && s->c != Ctrl_N && s->c != Ctrl_P && s->c != Ctrl_A
                      && s->c != Ctrl_L);
 end_wildmenu = end_wildmenu && (!cmdline_pum_active()
                                 || (s->c != K_PAGEDOWN && s->c != K_PAGEUP
                                     && s->c != K_KPAGEDOWN && s->c != K_KPAGEUP));

 // free expanded names when finished walking through matches
 if (end_wildmenu) {
   command_line_end_wildmenu(s, key_is_wc);
 }

 if (p_wmnu) {
   s->c = wildmenu_process_key(&ccline, s->c, &s->xpc);
 }

 // CTRL-\ CTRL-N or CTRL-\ CTRL-G goes to Normal mode,
 // CTRL-\ e prompts for an expression.
 if (s->c == Ctrl_BSL) {
   switch (command_line_handle_ctrl_bsl(s)) {
   case CMDLINE_CHANGED:
     return command_line_changed(s);
   case CMDLINE_NOT_CHANGED:
     return command_line_not_changed(s);
   case GOTO_NORMAL_MODE:
     return 0;                   // back to cmd mode
   default:
     s->c = Ctrl_BSL;            // backslash key not processed by
                                 // command_line_handle_ctrl_bsl()
   }
 }

 if (s->c == cedit_key || s->c == K_CMDWIN) {
   // TODO(vim): why is ex_normal_busy checked here?
   if ((s->c == K_CMDWIN || ex_normal_busy == 0)
       && got_int == false) {
     // Open a window to edit the command line (and history).
     s->c = open_cmdwin();
     s->some_key_typed = true;
   }
 } else {
   s->c = do_digraph(s->c);
 }

 if (s->c == '\n'
     || s->c == '\r'
     || s->c == K_KENTER
     || (s->c == ESC
         && (!KeyTyped || vim_strchr(p_cpo, CPO_ESC) != NULL))) {
   // In Ex mode a backslash escapes a newline.
   if (exmode_active
       && s->c != ESC
       && ccline.cmdpos == ccline.cmdlen
       && ccline.cmdpos > 0
       && ccline.cmdbuff[ccline.cmdpos - 1] == '\\') {
     if (s->c == K_KENTER) {
       s->c = '\n';
     }
   } else {
     s->gotesc = false;         // Might have typed ESC previously, don't
                                // truncate the cmdline now.
     if (ccheck_abbr(s->c + ABBR_OFF)) {
       return command_line_changed(s);
     }

     if (!cmd_silent) {
       if (!ui_has(kUICmdline)) {
         msg_cursor_goto(msg_row, 0);
       }
       ui_flush();
     }
     return 0;
   }
 }

 // Completion for 'wildchar', 'wildcharm', and wildtrigger()
 if ((s->c == p_wc && !s->gotesc && KeyTyped) || s->c == p_wcm || s->c == K_WILD
     || s->c == Ctrl_Z) {
   if (s->c == K_WILD) {
     emsg_silent++;  // Silence the bell
   }
   int res = command_line_wildchar_complete(s);
   if (s->c == K_WILD) {
     emsg_silent--;
   }
   if (res == CMDLINE_CHANGED) {
     return command_line_changed(s);
   }
   if (s->c == K_WILD) {
     return command_line_not_changed(s);
   }
 }

 s->gotesc = false;

 // <S-Tab> goes to last match, in a clumsy way
 if (s->c == K_S_TAB && KeyTyped) {
   if (nextwild(&s->xpc, WILD_EXPAND_KEEP, 0, s->firstc != '@') == OK) {
     if (s->xpc.xp_numfiles > 1
         && ((!s->did_wild_list && (wim_flags[s->wim_index] & kOptWimFlagList)) || p_wmnu)) {
       // Trigger the popup menu when wildoptions=pum
       showmatches(&s->xpc, p_wmnu, wim_flags[s->wim_index] & kOptWimFlagList,
                   wim_flags[0] & kOptWimFlagNoselect);
     }
     nextwild(&s->xpc, WILD_PREV, 0, s->firstc != '@');
     nextwild(&s->xpc, WILD_PREV, 0, s->firstc != '@');
     return command_line_changed(s);
   }
 }

 if (s->c == NUL || s->c == K_ZERO) {
   // NUL is stored as NL
   s->c = NL;
 }

 s->do_abbr = true;             // default: check for abbreviation

 // If already used to cancel/accept wildmenu, don't process the key further.
 if (wild_type == WILD_CANCEL || wild_type == WILD_APPLY) {
   // Apply search highlighting
   if (s->is_state.winid != curwin->handle) {
     init_incsearch_state(&s->is_state);
   }
   if (KeyTyped || vpeekc() == NUL) {
     may_do_incsearch_highlighting(s->firstc, s->count, &s->is_state);
   }
   return command_line_not_changed(s);
 }

 return command_line_handle_key(s);
}

// May adjust 'incsearch' highlighting for typing CTRL-G and CTRL-T, go to next
// or previous match.
// Returns FAIL when calling command_line_not_changed.
static int may_do_command_line_next_incsearch(int firstc, int count, incsearch_state_T *s,
                                             bool next_match)
 FUNC_ATTR_NONNULL_ALL
{
 int skiplen, patlen, search_delim;

 // Parsing range may already set the last search pattern.
 // NOTE: must call restore_last_search_pattern() before returning!
 save_last_search_pattern();

 if (!do_incsearch_highlighting(firstc, &search_delim, s, &skiplen,
                                &patlen)) {
   restore_last_search_pattern();
   return OK;
 }
 if (patlen == 0 && ccline.cmdbuff[skiplen] == NUL) {
   restore_last_search_pattern();
   return FAIL;
 }

 ui_busy_start();
 ui_flush();

 pos_T t;
 char *pat;
 int search_flags = SEARCH_NOOF;

 if (search_delim == ccline.cmdbuff[skiplen]) {
   pat = last_search_pattern();
   if (pat == NULL) {
     restore_last_search_pattern();
     return FAIL;
   }
   skiplen = 0;
   patlen = (int)last_search_pattern_len();
 } else {
   pat = ccline.cmdbuff + skiplen;
 }

 bool bslsh = false;
 // do not search for the search end delimiter,
 // unless it is part of the pattern
 if (patlen > 2 && firstc == pat[patlen - 1]) {
   patlen--;
   if (pat[patlen - 1] == '\\') {
     pat[patlen - 1] = (char)(uint8_t)firstc;
     bslsh = true;
   }
 }

 if (next_match) {
   t = s->match_end;
   if (lt(s->match_start, s->match_end)) {
     // start searching at the end of the match
     // not at the beginning of the next column
     decl(&t);
   }
   search_flags += SEARCH_COL;
 } else {
   t = s->match_start;
 }
 if (!p_hls) {
   search_flags += SEARCH_KEEP;
 }
 emsg_off++;
 char save = pat[patlen];
 pat[patlen] = NUL;
 int found = searchit(curwin, curbuf, &t, NULL,
                      next_match ? FORWARD : BACKWARD,
                      pat, (size_t)patlen, count, search_flags,
                      RE_SEARCH, NULL);
 emsg_off--;
 pat[patlen] = save;
 if (bslsh) {
   pat[patlen - 1] = '\\';
 }
 ui_busy_stop();
 if (found) {
   s->search_start = s->match_start;
   s->match_end = t;
   s->match_start = t;
   if (!next_match && firstc != '?') {
     // move just before the current match, so that
     // when nv_search finishes the cursor will be
     // put back on the match
     s->search_start = t;
     decl(&s->search_start);
   } else if (next_match && firstc == '?') {
     // move just after the current match, so that
     // when nv_search finishes the cursor will be
     // put back on the match
     s->search_start = t;
     incl(&s->search_start);
   }
   if (lt(t, s->search_start) && next_match) {
     // wrap around
     s->search_start = t;
     if (firstc == '?') {
       incl(&s->search_start);
     } else {
       decl(&s->search_start);
     }
   }

   set_search_match(&s->match_end);
   curwin->w_cursor = s->match_start;
   changed_cline_bef_curs(curwin);
   update_topline(curwin);
   validate_cursor(curwin);
   highlight_match = true;
   save_viewstate(curwin, &s->old_viewstate);
   redraw_later(curwin, UPD_NOT_VALID);
   update_screen();
   highlight_match = false;
   redrawcmdline();
   curwin->w_cursor = s->match_end;
 } else {
   vim_beep(kOptBoFlagError);
 }
 restore_last_search_pattern();
 return FAIL;
}

/// Handle backspace, delete and CTRL-W keys in the command-line mode.
static int command_line_erase_chars(CommandLineState *s)
{
 if (s->c == K_KDEL) {
   s->c = K_DEL;
 }

 // Delete current character is the same as backspace on next
 // character, except at end of line
 if (s->c == K_DEL && ccline.cmdpos != ccline.cmdlen) {
   ccline.cmdpos++;
 }
 if (s->c == K_DEL) {
   ccline.cmdpos += mb_off_next(ccline.cmdbuff, ccline.cmdbuff + ccline.cmdpos);
 }

 if (ccline.cmdpos > 0) {
   int j = ccline.cmdpos;
   char *p = mb_prevptr(ccline.cmdbuff, ccline.cmdbuff + j);

   if (s->c == Ctrl_W) {
     while (p > ccline.cmdbuff && ascii_isspace(*p)) {
       p = mb_prevptr(ccline.cmdbuff, p);
     }

     int i = mb_get_class(p);
     while (p > ccline.cmdbuff && mb_get_class(p) == i) {
       p = mb_prevptr(ccline.cmdbuff, p);
     }

     if (mb_get_class(p) != i) {
       p += utfc_ptr2len(p);
     }
   }

   ccline.cmdpos = (int)(p - ccline.cmdbuff);
   ccline.cmdlen -= j - ccline.cmdpos;
   int i = ccline.cmdpos;

   while (i < ccline.cmdlen) {
     ccline.cmdbuff[i++] = ccline.cmdbuff[j++];
   }

   // Truncate at the end, required for multi-byte chars.
   ccline.cmdbuff[ccline.cmdlen] = NUL;
   if (ccline.cmdlen == 0) {
     s->is_state.search_start = s->is_state.save_cursor;
     // save view settings, so that the screen won't be restored at the
     // wrong position
     s->is_state.old_viewstate = s->is_state.init_viewstate;
   }
   redrawcmd();
 } else if (ccline.cmdlen == 0 && s->c != Ctrl_W
            && ccline.cmdprompt == NULL && s->indent == 0) {
   // In ex and debug mode it doesn't make sense to return.
   if (exmode_active || ccline.cmdfirstc == '>') {
     return CMDLINE_NOT_CHANGED;
   }

   dealloc_cmdbuff();  // no commandline to return

   if (!cmd_silent && !ui_has(kUICmdline)) {
     msg_col = 0;
     msg_putchar(' ');                             // delete ':'
   }
   s->is_state.search_start = s->is_state.save_cursor;
   redraw_cmdline = true;
   return GOTO_NORMAL_MODE;
 }
 return CMDLINE_CHANGED;
}

/// Handle the CTRL-^ key in the command-line mode and toggle the use of the
/// language :lmap mappings and/or Input Method.
static void command_line_toggle_langmap(CommandLineState *s)
{
 OptInt *b_im_ptr = buf_valid(s->b_im_ptr_buf) ? s->b_im_ptr : NULL;
 if (map_to_exists_mode("", MODE_LANGMAP, false)) {
   // ":lmap" mappings exists, toggle use of mappings.
   State ^= MODE_LANGMAP;
   if (b_im_ptr != NULL) {
     if (State & MODE_LANGMAP) {
       *b_im_ptr = B_IMODE_LMAP;
     } else {
       *b_im_ptr = B_IMODE_NONE;
     }
   }
 }

 if (b_im_ptr != NULL) {
   if (b_im_ptr == &curbuf->b_p_iminsert) {
     set_iminsert_global(curbuf);
   } else {
     set_imsearch_global(curbuf);
   }
 }
 ui_cursor_shape();                // may show different cursor shape
 // Show/unshow value of 'keymap' in status lines later.
 status_redraw_curbuf();
}

/// Handle the CTRL-R key in the command-line mode and insert the contents of a
/// numbered or named register.
static int command_line_insert_reg(CommandLineState *s)
{
 const int save_new_cmdpos = new_cmdpos;

 putcmdline('"', true);
 no_mapping++;
 allow_keys++;
 int i = s->c = plain_vgetc();      // CTRL-R <char>
 if (i == Ctrl_O) {
   i = Ctrl_R;                      // CTRL-R CTRL-O == CTRL-R CTRL-R
 }

 if (i == Ctrl_R) {
   s->c = plain_vgetc();              // CTRL-R CTRL-R <char>
 }
 no_mapping--;
 allow_keys--;
 // Insert the result of an expression.
 new_cmdpos = -1;
 if (s->c == '=') {
   if (ccline.cmdfirstc == '='   // can't do this recursively
       || cmdline_star > 0) {    // or when typing a password
     beep_flush();
     s->c = ESC;
   } else {
     s->c = get_expr_register();
   }
 }

 bool literally = false;
 if (s->c != ESC) {               // use ESC to cancel inserting register
   literally = i == Ctrl_R || is_literal_register(s->c);
   cmdline_paste(s->c, literally, false);

   // When there was a serious error abort getting the
   // command line.
   if (aborting()) {
     s->gotesc = true;              // will free ccline.cmdbuff after
                                    // putting it in history
     return GOTO_NORMAL_MODE;
   }
   KeyTyped = false;                // Don't do p_wc completion.
   if (new_cmdpos >= 0) {
     // set_cmdline_pos() was used
     ccline.cmdpos = MIN(ccline.cmdlen, new_cmdpos);
   }
 }
 new_cmdpos = save_new_cmdpos;

 // remove the double quote
 ccline.special_char = NUL;
 redrawcmd();

 // With "literally": the command line has already changed.
 // Else: the text has been stuffed, but the command line didn't change yet.
 return literally ? CMDLINE_CHANGED : CMDLINE_NOT_CHANGED;
}

/// Handle the Left and Right mouse clicks in the command-line mode.
static void command_line_left_right_mouse(CommandLineState *s)
{
 if (s->c == K_LEFTRELEASE || s->c == K_RIGHTRELEASE) {
   s->ignore_drag_release = true;
 } else {
   s->ignore_drag_release = false;
 }

 ccline.cmdspos = cmd_startcol();
 for (ccline.cmdpos = 0; ccline.cmdpos < ccline.cmdlen;
      ccline.cmdpos++) {
   int cells = cmdline_charsize(ccline.cmdpos);
   if (mouse_row <= cmdline_row + ccline.cmdspos / Columns
       && mouse_col < ccline.cmdspos % Columns + cells) {
     break;
   }

   // Count ">" for double-wide char that doesn't fit.
   correct_screencol(ccline.cmdpos, cells, &ccline.cmdspos);
   ccline.cmdpos += utfc_ptr2len(ccline.cmdbuff + ccline.cmdpos) - 1;
   ccline.cmdspos += cells;
 }
}

static void command_line_next_histidx(CommandLineState *s, bool next_match)
{
 while (true) {
   // one step backwards
   if (!next_match) {
     if (s->hiscnt == get_hislen()) {
       // first time
       s->hiscnt = *get_hisidx(s->histype);
     } else if (s->hiscnt == 0 && *get_hisidx(s->histype) != get_hislen() - 1) {
       s->hiscnt = get_hislen() - 1;
     } else if (s->hiscnt != *get_hisidx(s->histype) + 1) {
       s->hiscnt--;
     } else {
       // at top of list
       s->hiscnt = s->save_hiscnt;
       break;
     }
   } else {          // one step forwards
     // on last entry, clear the line
     if (s->hiscnt == *get_hisidx(s->histype)) {
       s->hiscnt = get_hislen();
       break;
     }

     // not on a history line, nothing to do
     if (s->hiscnt == get_hislen()) {
       break;
     }

     if (s->hiscnt == get_hislen() - 1) {
       // wrap around
       s->hiscnt = 0;
     } else {
       s->hiscnt++;
     }
   }

   if (s->hiscnt < 0 || get_histentry(s->histype)[s->hiscnt].hisstr == NULL) {
     s->hiscnt = s->save_hiscnt;
     break;
   }

   if ((s->c != K_UP && s->c != K_DOWN)
       || s->hiscnt == s->save_hiscnt
       || strncmp(get_histentry(s->histype)[s->hiscnt].hisstr,
                  s->lookfor, (size_t)s->lookforlen) == 0) {
     break;
   }
 }
}

/// Handle the Up, Down, Page Up, Page down, CTRL-N and CTRL-P key in the
/// command-line mode.
static int command_line_browse_history(CommandLineState *s)
{
 if (s->histype == HIST_INVALID || get_hislen() == 0 || s->firstc == NUL) {
   // no history
   return CMDLINE_NOT_CHANGED;
 }

 s->save_hiscnt = s->hiscnt;

 // save current command string so it can be restored later
 if (s->lookfor == NULL) {
   s->lookfor = xstrnsave(ccline.cmdbuff, (size_t)ccline.cmdlen);
   s->lookfor[ccline.cmdpos] = NUL;
   s->lookforlen = ccline.cmdpos;
 }

 bool next_match = (s->c == K_DOWN || s->c == K_S_DOWN || s->c == Ctrl_N
                    || s->c == K_PAGEDOWN || s->c == K_KPAGEDOWN);
 command_line_next_histidx(s, next_match);

 if (s->hiscnt != s->save_hiscnt) {  // jumped to other entry
   char *p;
   int plen;
   int old_firstc;

   dealloc_cmdbuff();

   s->xpc.xp_context = EXPAND_NOTHING;
   if (s->hiscnt == get_hislen()) {
     p = s->lookfor;                  // back to the old one
     plen = s->lookforlen;
   } else {
     p = get_histentry(s->histype)[s->hiscnt].hisstr;
     plen = (int)get_histentry(s->histype)[s->hiscnt].hisstrlen;
   }

   if (s->histype == HIST_SEARCH
       && p != s->lookfor
       && (old_firstc = (uint8_t)p[plen + 1]) != s->firstc) {
     int len = 0;
     // Correct for the separator character used when
     // adding the history entry vs the one used now.
     // First loop: count length.
     // Second loop: copy the characters.
     for (int i = 0; i <= 1; i++) {
       len = 0;
       for (int j = 0; p[j] != NUL; j++) {
         // Replace old sep with new sep, unless it is
         // escaped.
         if (p[j] == old_firstc
             && (j == 0 || p[j - 1] != '\\')) {
           if (i > 0) {
             ccline.cmdbuff[len] = (char)s->firstc;
           }
         } else {
           // Escape new sep, unless it is already
           // escaped.
           if (p[j] == s->firstc
               && (j == 0 || p[j - 1] != '\\')) {
             if (i > 0) {
               ccline.cmdbuff[len] = '\\';
             }
             len++;
           }

           if (i > 0) {
             ccline.cmdbuff[len] = p[j];
           }
         }
         len++;
       }

       if (i == 0) {
         alloc_cmdbuff(len);
       }
     }
     ccline.cmdbuff[len] = NUL;
     ccline.cmdpos = ccline.cmdlen = len;
   } else {
     alloc_cmdbuff(plen);
     STRCPY(ccline.cmdbuff, p);
     ccline.cmdpos = ccline.cmdlen = plen;
   }

   redrawcmd();
   return CMDLINE_CHANGED;
 }
 beep_flush();
 return CMDLINE_NOT_CHANGED;
}

static int command_line_handle_key(CommandLineState *s)
{
 // For one key prompt, avoid putting ESC and Ctrl_C onto cmdline.
 // For all other keys, just put onto cmdline and exit.
 if (ccline.one_key && s->c != ESC && s->c != Ctrl_C) {
   goto end;
 }

 // Big switch for a typed command line character.
 switch (s->c) {
 case K_BS:
 case Ctrl_H:
 case K_DEL:
 case K_KDEL:
 case Ctrl_W:
   switch (command_line_erase_chars(s)) {
   case CMDLINE_NOT_CHANGED:
     return command_line_not_changed(s);
   case GOTO_NORMAL_MODE:
     return 0;  // back to cmd mode
   default:
     return command_line_changed(s);
   }

 case K_INS:
 case K_KINS:
   ccline.overstrike = !ccline.overstrike;
   ui_cursor_shape();                // may show different cursor shape
   may_trigger_modechanged();
   status_redraw_curbuf();
   redraw_statuslines();
   return command_line_not_changed(s);

 case Ctrl_HAT:
   command_line_toggle_langmap(s);
   return command_line_not_changed(s);

 case Ctrl_U: {
   // delete all characters left of the cursor
   int j = ccline.cmdpos;
   ccline.cmdlen -= j;
   int i = ccline.cmdpos = 0;
   while (i < ccline.cmdlen) {
     ccline.cmdbuff[i++] = ccline.cmdbuff[j++];
   }

   // Truncate at the end, required for multi-byte chars.
   ccline.cmdbuff[ccline.cmdlen] = NUL;
   if (ccline.cmdlen == 0) {
     s->is_state.search_start = s->is_state.save_cursor;
   }
   redrawcmd();
   return command_line_changed(s);
 }

 case ESC:           // get here if p_wc != ESC or when ESC typed twice
 case Ctrl_C:
   // In exmode it doesn't make sense to return.  Except when
   // ":normal" runs out of characters. Also when highlight callback is active
   // <C-c> should interrupt only it.
   if ((exmode_active && (ex_normal_busy == 0 || typebuf.tb_len > 0))
       || (getln_interrupted_highlight && s->c == Ctrl_C)) {
     getln_interrupted_highlight = false;
     return command_line_not_changed(s);
   }

   s->gotesc = true;                 // will free ccline.cmdbuff after
                                     // putting it in history
   return 0;                         // back to cmd mode

 case Ctrl_R:                        // insert register
   switch (command_line_insert_reg(s)) {
   case GOTO_NORMAL_MODE:
     return 0;  // back to cmd mode
   case CMDLINE_CHANGED:
     return command_line_changed(s);
   default:
     return command_line_not_changed(s);
   }

 case Ctrl_D:
   if (showmatches(&s->xpc, false, true, wim_flags[0] & kOptWimFlagNoselect)
       == EXPAND_NOTHING) {
     break;                  // Use ^D as normal char instead
   }

   redrawcmd();
   return 1;                 // don't do incremental search now

 case K_RIGHT:
 case K_S_RIGHT:
 case K_C_RIGHT:
   do {
     if (ccline.cmdpos >= ccline.cmdlen) {
       break;
     }

     int cells = cmdline_charsize(ccline.cmdpos);
     if (KeyTyped && ccline.cmdspos + cells >= Columns * Rows) {
       break;
     }

     ccline.cmdspos += cells;
     ccline.cmdpos += utfc_ptr2len(ccline.cmdbuff + ccline.cmdpos);
   } while ((s->c == K_S_RIGHT || s->c == K_C_RIGHT
             || (mod_mask & (MOD_MASK_SHIFT|MOD_MASK_CTRL)))
            && ccline.cmdbuff[ccline.cmdpos] != ' ');
   ccline.cmdspos = cmd_screencol(ccline.cmdpos);
   return command_line_not_changed(s);

 case K_LEFT:
 case K_S_LEFT:
 case K_C_LEFT:
   if (ccline.cmdpos == 0) {
     return command_line_not_changed(s);
   }
   do {
     ccline.cmdpos--;
     // Move to first byte of possibly multibyte char.
     ccline.cmdpos -= utf_head_off(ccline.cmdbuff,
                                   ccline.cmdbuff + ccline.cmdpos);
     ccline.cmdspos -= cmdline_charsize(ccline.cmdpos);
   } while (ccline.cmdpos > 0
            && (s->c == K_S_LEFT || s->c == K_C_LEFT
                || (mod_mask & (MOD_MASK_SHIFT|MOD_MASK_CTRL)))
            && ccline.cmdbuff[ccline.cmdpos - 1] != ' ');

   ccline.cmdspos = cmd_screencol(ccline.cmdpos);
   if (ccline.special_char != NUL) {
     putcmdline(ccline.special_char, ccline.special_shift);
   }

   return command_line_not_changed(s);

 case K_IGNORE:
   // Ignore mouse event or open_cmdwin() result.
   return command_line_not_changed(s);

 case K_MIDDLEDRAG:
 case K_MIDDLERELEASE:
   return command_line_not_changed(s);                 // Ignore mouse

 case K_MIDDLEMOUSE:
   cmdline_paste(eval_has_provider("clipboard", false) ? '*' : 0, true, true);
   redrawcmd();
   return command_line_changed(s);

 case K_LEFTDRAG:
 case K_LEFTRELEASE:
 case K_RIGHTDRAG:
 case K_RIGHTRELEASE:
   // Ignore drag and release events when the button-down wasn't
   // seen before.
   if (s->ignore_drag_release) {
     return command_line_not_changed(s);
   }
   FALLTHROUGH;
 case K_LEFTMOUSE:
   // Return on left click above number prompt
   if (ccline.mouse_used && mouse_row < cmdline_row) {
     *ccline.mouse_used = true;
     return 0;
   }
   FALLTHROUGH;
 case K_RIGHTMOUSE:
   command_line_left_right_mouse(s);
   return command_line_not_changed(s);

 // Mouse scroll wheel: ignored here
 case K_MOUSEDOWN:
 case K_MOUSEUP:
 case K_MOUSELEFT:
 case K_MOUSERIGHT:
 // Alternate buttons ignored here
 case K_X1MOUSE:
 case K_X1DRAG:
 case K_X1RELEASE:
 case K_X2MOUSE:
 case K_X2DRAG:
 case K_X2RELEASE:
 case K_MOUSEMOVE:
   return command_line_not_changed(s);

 case K_SELECT:          // end of Select mode mapping - ignore
   return command_line_not_changed(s);

 case Ctrl_B:            // begin of command line
 case K_HOME:
 case K_KHOME:
 case K_S_HOME:
 case K_C_HOME:
   ccline.cmdpos = 0;
   ccline.cmdspos = cmd_startcol();
   return command_line_not_changed(s);

 case Ctrl_E:            // end of command line
 case K_END:
 case K_KEND:
 case K_S_END:
 case K_C_END:
   ccline.cmdpos = ccline.cmdlen;
   ccline.cmdspos = cmd_screencol(ccline.cmdpos);
   return command_line_not_changed(s);

 case Ctrl_A:            // all matches
   if (cmdline_pum_active()) {
     // As Ctrl-A completes all the matches, close the popup
     // menu (if present)
     cmdline_pum_cleanup(&ccline);
   }

   if (nextwild(&s->xpc, WILD_ALL, 0, s->firstc != '@') == FAIL) {
     break;
   }
   s->xpc.xp_context = EXPAND_NOTHING;
   s->did_wild_list = false;
   return command_line_changed(s);

 case Ctrl_L:
   if (may_add_char_to_search(s->firstc, &s->c, &s->is_state) == OK) {
     return command_line_not_changed(s);
   }

   // completion: longest common part
   if (nextwild(&s->xpc, WILD_LONGEST, 0, s->firstc != '@') == FAIL) {
     break;
   }
   return command_line_changed(s);

 case Ctrl_N:            // next match
 case Ctrl_P:            // previous match
   if (s->xpc.xp_numfiles > 0) {
     const int wild_type = (s->c == Ctrl_P) ? WILD_PREV : WILD_NEXT;
     if (nextwild(&s->xpc, wild_type, 0, s->firstc != '@') == FAIL) {
       break;
     }
     return command_line_changed(s);
   }
   FALLTHROUGH;

 case K_UP:
 case K_DOWN:
 case K_S_UP:
 case K_S_DOWN:
 case K_PAGEUP:
 case K_KPAGEUP:
 case K_PAGEDOWN:
 case K_KPAGEDOWN:
   if (cmdline_pum_active()
       && (s->c == K_PAGEUP || s->c == K_PAGEDOWN
           || s->c == K_KPAGEUP || s->c == K_KPAGEDOWN)) {
     // If the popup menu is displayed, then PageUp and PageDown
     // are used to scroll the menu.
     const int wild_type =
       (s->c == K_PAGEDOWN || s->c == K_KPAGEDOWN) ? WILD_PAGEDOWN : WILD_PAGEUP;
     if (nextwild(&s->xpc, wild_type, 0, s->firstc != '@') == FAIL) {
       break;
     }
     return command_line_changed(s);
   } else {
     switch (command_line_browse_history(s)) {
     case CMDLINE_CHANGED:
       s->did_hist_navigate = true;
       return command_line_changed(s);
     case GOTO_NORMAL_MODE:
       return 0;
     default:
       return command_line_not_changed(s);
     }
   }

 case Ctrl_G:  // next match
 case Ctrl_T:  // previous match
   if (may_do_command_line_next_incsearch(s->firstc, s->count, &s->is_state,
                                          s->c == Ctrl_G) == FAIL) {
     return command_line_not_changed(s);
   }
   break;

 case Ctrl_V:
 case Ctrl_Q:
   s->ignore_drag_release = true;
   putcmdline('^', true);

   // Get next (two) characters.
   // Do not include modifiers into the key for CTRL-SHIFT-V.
   s->c = get_literal(mod_mask & MOD_MASK_SHIFT);

   s->do_abbr = false;                   // don't do abbreviation now
   ccline.special_char = NUL;
   // may need to remove ^ when composing char was typed
   if (utf_iscomposing_first(s->c) && !cmd_silent) {
     if (ui_has(kUICmdline)) {
       // TODO(bfredl): why not make unputcmdline also work with true?
       unputcmdline();
     } else {
       draw_cmdline(ccline.cmdpos, ccline.cmdlen - ccline.cmdpos);
       msg_putchar(' ');
       cursorcmd();
     }
   }
   break;

 case Ctrl_K:
   s->ignore_drag_release = true;
   putcmdline('?', true);
   s->c = get_digraph(true);
   ccline.special_char = NUL;

   if (s->c != NUL) {
     break;
   }

   redrawcmd();
   return command_line_not_changed(s);

 case Ctrl__:            // CTRL-_: switch language mode
   if (!p_ari) {
     break;
   }
   return command_line_not_changed(s);

 case 'q':
   // Number prompts use the mouse and return on 'q' press
   if (ccline.mouse_used) {
     *ccline.cmdbuff = NUL;
     return 0;
   }
   FALLTHROUGH;

 default:
   // Normal character with no special meaning.  Just set mod_mask
   // to 0x0 so that typing Shift-Space in the GUI doesn't enter
   // the string <S-Space>.  This should only happen after ^V.
   if (!IS_SPECIAL(s->c)) {
     mod_mask = 0x0;
   }
   break;
 }

 // End of switch on command line character.
 // We come here if we have a normal character.
 if (s->do_abbr && (IS_SPECIAL(s->c) || !vim_iswordc(s->c))
     // Add ABBR_OFF for characters above 0x100, this is
     // what check_abbr() expects.
     && (ccheck_abbr((s->c >= 0x100) ? (s->c + ABBR_OFF) : s->c)
         || s->c == Ctrl_RSB)) {
   return command_line_changed(s);
 }

end:
 // put the character in the command line
 if (IS_SPECIAL(s->c) || mod_mask != 0) {
   put_on_cmdline(get_special_key_name(s->c, mod_mask), -1, true);
 } else {
   int j = utf_char2bytes(s->c, IObuff);
   IObuff[j] = NUL;                // exclude composing chars
   put_on_cmdline(IObuff, j, true);
 }
 return ccline.one_key ? 0 : command_line_changed(s);
}

/// Trigger CursorMovedC autocommands.
static void may_trigger_cursormovedc(CommandLineState *s)
{
 if (ccline.cmdpos != s->prev_cmdpos) {
   trigger_cmd_autocmd(s->cmdline_type, EVENT_CURSORMOVEDC);
   ccline.redraw_state = MAX(ccline.redraw_state, kCmdRedrawPos);
 }
}

static int command_line_not_changed(CommandLineState *s)
{
 may_trigger_cursormovedc(s);
 s->prev_cmdpos = ccline.cmdpos;
 // Incremental searches for "/" and "?":
 // Enter command_line_not_changed() when a character has been read but the
 // command line did not change. Then we only search and redraw if something
 // changed in the past.
 // Enter command_line_changed() when the command line did change.
 if (!s->is_state.incsearch_postponed) {
   return 1;
 }
 return command_line_changed(s);
}

/// Guess that the pattern matches everything.  Only finds specific cases, such
/// as a trailing \|, which can happen while typing a pattern.
static bool empty_pattern(char *p, size_t len, int delim)
{
 magic_T magic_val = MAGIC_ON;

 if (len > 0) {
   skip_regexp_ex(p, delim, magic_isset(), NULL, NULL, &magic_val);
 } else {
   return true;
 }

 return empty_pattern_magic(p, len, magic_val);
}

static bool empty_pattern_magic(char *p, size_t len, magic_T magic_val)
{
 // remove trailing \v and the like
 while (len >= 2 && p[len - 2] == '\\'
        && vim_strchr("mMvVcCZ", (uint8_t)p[len - 1]) != NULL) {
   len -= 2;
 }

 // true, if the pattern is empty, or the pattern ends with \| and magic is
 // set (or it ends with '|' and very magic is set)
 return len == 0 || (len > 1 && p[len - 1] == '|'
                     && ((p[len - 2] == '\\' && magic_val == MAGIC_ON)
                         || (p[len - 2] != '\\' && magic_val == MAGIC_ALL)));
}

handle_T cmdpreview_get_bufnr(void)
{
 return cmdpreview_bufnr;
}

int cmdpreview_get_ns(void)
{
 return cmdpreview_ns;
}

/// Sets up command preview buffer.
///
/// @return Pointer to command preview buffer if succeeded, NULL if failed.
static buf_T *cmdpreview_open_buf(void)
{
 buf_T *cmdpreview_buf = cmdpreview_bufnr ? buflist_findnr(cmdpreview_bufnr) : NULL;

 // If preview buffer doesn't exist, open one.
 if (cmdpreview_buf == NULL) {
   Error err = ERROR_INIT;
   handle_T bufnr = nvim_create_buf(false, true, &err);

   if (ERROR_SET(&err)) {
     return NULL;
   }

   cmdpreview_buf = buflist_findnr(bufnr);
 }

 // Preview buffer cannot preview itself!
 if (cmdpreview_buf == curbuf) {
   return NULL;
 }

 // Rename preview buffer.
 aco_save_T aco;
 aucmd_prepbuf(&aco, cmdpreview_buf);
 int retv = rename_buffer("[Preview]");
 aucmd_restbuf(&aco);

 if (retv == FAIL) {
   return NULL;
 }

 // Temporarily switch to preview buffer to set it up for previewing.
 aucmd_prepbuf(&aco, cmdpreview_buf);
 buf_clear();
 curbuf->b_p_ma = true;
 curbuf->b_p_ul = -1;
 curbuf->b_p_tw = 0;  // Reset 'textwidth' (was set by ftplugin)
 aucmd_restbuf(&aco);
 cmdpreview_bufnr = cmdpreview_buf->handle;

 return cmdpreview_buf;
}

/// Open command preview window if it's not already open.
/// Returns to original window after opening command preview window.
///
/// @param cmdpreview_buf Pointer to command preview buffer
///
/// @return Pointer to command preview window if succeeded, NULL if failed.
static win_T *cmdpreview_open_win(buf_T *cmdpreview_buf)
 FUNC_ATTR_NONNULL_ALL
{
 win_T *save_curwin = curwin;

 // Open preview window.
 if (win_split((int)p_cwh, WSP_BOT) == FAIL) {
   return NULL;
 }

 win_T *preview_win = curwin;
 Error err = ERROR_INIT;
 int result = OK;

 // Switch to preview buffer
 TRY_WRAP(&err, {
   result = do_buffer(DOBUF_GOTO, DOBUF_FIRST, FORWARD, cmdpreview_buf->handle, 0);
 });
 if (ERROR_SET(&err) || result == FAIL) {
   api_clear_error(&err);
   return NULL;
 }

 curwin->w_p_cul = false;
 curwin->w_p_cuc = false;
 curwin->w_p_spell = false;
 curwin->w_p_fen = false;

 win_enter(save_curwin, false);
 return preview_win;
}

/// Closes any open command preview windows.
static void cmdpreview_close_win(void)
{
 buf_T *buf = cmdpreview_bufnr ? buflist_findnr(cmdpreview_bufnr) : NULL;
 if (buf != NULL) {
   close_windows(buf, false);
 }
}

/// Save the undo state of a buffer for command preview.
static void cmdpreview_save_undo(CpUndoInfo *cp_undoinfo, buf_T *buf)
 FUNC_ATTR_NONNULL_ALL
{
 cp_undoinfo->save_b_u_synced = buf->b_u_synced;
 cp_undoinfo->save_b_u_oldhead = buf->b_u_oldhead;
 cp_undoinfo->save_b_u_newhead = buf->b_u_newhead;
 cp_undoinfo->save_b_u_curhead = buf->b_u_curhead;
 cp_undoinfo->save_b_u_numhead = buf->b_u_numhead;
 cp_undoinfo->save_b_u_seq_last = buf->b_u_seq_last;
 cp_undoinfo->save_b_u_save_nr_last = buf->b_u_save_nr_last;
 cp_undoinfo->save_b_u_seq_cur = buf->b_u_seq_cur;
 cp_undoinfo->save_b_u_time_cur = buf->b_u_time_cur;
 cp_undoinfo->save_b_u_save_nr_cur = buf->b_u_save_nr_cur;
 cp_undoinfo->save_b_u_line_ptr = buf->b_u_line_ptr;
 cp_undoinfo->save_b_u_line_lnum = buf->b_u_line_lnum;
 cp_undoinfo->save_b_u_line_colnr = buf->b_u_line_colnr;
}

/// Restore the undo state of a buffer for command preview.
static void cmdpreview_restore_undo(const CpUndoInfo *cp_undoinfo, buf_T *buf)
{
 buf->b_u_oldhead = cp_undoinfo->save_b_u_oldhead;
 buf->b_u_newhead = cp_undoinfo->save_b_u_newhead;
 buf->b_u_curhead = cp_undoinfo->save_b_u_curhead;
 buf->b_u_numhead = cp_undoinfo->save_b_u_numhead;
 buf->b_u_seq_last = cp_undoinfo->save_b_u_seq_last;
 buf->b_u_save_nr_last = cp_undoinfo->save_b_u_save_nr_last;
 buf->b_u_seq_cur = cp_undoinfo->save_b_u_seq_cur;
 buf->b_u_time_cur = cp_undoinfo->save_b_u_time_cur;
 buf->b_u_save_nr_cur = cp_undoinfo->save_b_u_save_nr_cur;
 buf->b_u_line_ptr = cp_undoinfo->save_b_u_line_ptr;
 buf->b_u_line_lnum = cp_undoinfo->save_b_u_line_lnum;
 buf->b_u_line_colnr = cp_undoinfo->save_b_u_line_colnr;
 if (buf->b_u_curhead == NULL) {
   buf->b_u_synced = cp_undoinfo->save_b_u_synced;
 }
}

/// Save current state and prepare windows and buffers for command preview.
static void cmdpreview_prepare(CpInfo *cpinfo)
 FUNC_ATTR_NONNULL_ALL
{
 Set(ptr_t) saved_bufs = SET_INIT;

 kv_init(cpinfo->buf_info);
 kv_init(cpinfo->win_info);

 FOR_ALL_WINDOWS_IN_TAB(win, curtab) {
   buf_T *buf = win->w_buffer;

   // Don't save state of command preview buffer or preview window.
   if (buf->handle == cmdpreview_bufnr) {
     continue;
   }

   if (!set_has(ptr_t, &saved_bufs, buf)) {
     CpBufInfo cp_bufinfo;
     cp_bufinfo.buf = buf;
     cp_bufinfo.save_b_p_ma = buf->b_p_ma;
     cp_bufinfo.save_b_p_ul = buf->b_p_ul;
     cp_bufinfo.save_b_changed = buf->b_changed;
     cp_bufinfo.save_b_op_start = buf->b_op_start;
     cp_bufinfo.save_b_op_end = buf->b_op_end;
     cp_bufinfo.save_changedtick = buf_get_changedtick(buf);
     cmdpreview_save_undo(&cp_bufinfo.undo_info, buf);
     kv_push(cpinfo->buf_info, cp_bufinfo);
     set_put(ptr_t, &saved_bufs, buf);

     u_clearall(buf);
     buf->b_p_ul = INT_MAX;  // Make sure we can undo all changes
   }

   CpWinInfo cp_wininfo;
   cp_wininfo.win = win;

   // Save window cursor position and viewstate
   cp_wininfo.save_w_cursor = win->w_cursor;
   save_viewstate(win, &cp_wininfo.save_viewstate);

   // Save 'cursorline' and 'cursorcolumn'
   cp_wininfo.save_w_p_cul = win->w_p_cul;
   cp_wininfo.save_w_p_cuc = win->w_p_cuc;

   kv_push(cpinfo->win_info, cp_wininfo);

   win->w_p_cul = false;       // Disable 'cursorline' so it doesn't mess up the highlights
   win->w_p_cuc = false;       // Disable 'cursorcolumn' so it doesn't mess up the highlights
 }

 set_destroy(ptr_t, &saved_bufs);

 cpinfo->save_hls = p_hls;
 cpinfo->save_cmdmod = cmdmod;
 win_size_save(&cpinfo->save_view);
 save_search_patterns();

 p_hls = false;                 // Don't show search highlighting during live substitution
 cmdmod.cmod_split = 0;         // Disable :leftabove/botright modifiers
 cmdmod.cmod_tab = 0;           // Disable :tab modifier
 cmdmod.cmod_flags |= CMOD_NOSWAPFILE;  // Disable swap for preview buffer

 u_sync(true);
}

/// Restore the state of buffers and windows for command preview.
static void cmdpreview_restore_state(CpInfo *cpinfo)
 FUNC_ATTR_NONNULL_ALL
{
 for (size_t i = 0; i < cpinfo->buf_info.size; i++) {
   CpBufInfo cp_bufinfo = cpinfo->buf_info.items[i];
   buf_T *buf = cp_bufinfo.buf;

   buf->b_changed = cp_bufinfo.save_b_changed;

   // Clear preview highlights.
   extmark_clear(buf, (uint32_t)cmdpreview_ns, 0, 0, MAXLNUM, MAXCOL);

   if (buf->b_u_seq_cur != cp_bufinfo.undo_info.save_b_u_seq_cur) {
     int count = 0;

     // Calculate how many undo steps are necessary to restore earlier state.
     for (u_header_T *uhp = buf->b_u_curhead ? buf->b_u_curhead : buf->b_u_newhead;
          uhp != NULL;
          uhp = uhp->uh_next.ptr, ++count) {}

     aco_save_T aco;
     aucmd_prepbuf(&aco, buf);
     // Ensure all the entries will be undone
     if (curbuf->b_u_synced == false) {
       u_sync(true);
     }
     // Undo invisibly. This also moves the cursor!
     if (!u_undo_and_forget(count, false)) {
       abort();
     }
     aucmd_restbuf(&aco);
   }

   u_blockfree(buf);
   cmdpreview_restore_undo(&cp_bufinfo.undo_info, buf);

   buf->b_op_start = cp_bufinfo.save_b_op_start;
   buf->b_op_end = cp_bufinfo.save_b_op_end;

   if (cp_bufinfo.save_changedtick != buf_get_changedtick(buf)) {
     buf_set_changedtick(buf, cp_bufinfo.save_changedtick);
   }

   buf->b_p_ul = cp_bufinfo.save_b_p_ul;        // Restore 'undolevels'
   buf->b_p_ma = cp_bufinfo.save_b_p_ma;        // Restore 'modifiable'
 }

 for (size_t i = 0; i < cpinfo->win_info.size; i++) {
   CpWinInfo cp_wininfo = cpinfo->win_info.items[i];
   win_T *win = cp_wininfo.win;

   // Restore window cursor position and viewstate
   win->w_cursor = cp_wininfo.save_w_cursor;
   restore_viewstate(win, &cp_wininfo.save_viewstate);

   // Restore 'cursorline' and 'cursorcolumn'
   win->w_p_cul = cp_wininfo.save_w_p_cul;
   win->w_p_cuc = cp_wininfo.save_w_p_cuc;

   update_topline(win);
 }

 cmdmod = cpinfo->save_cmdmod;                // Restore cmdmod
 p_hls = cpinfo->save_hls;                    // Restore 'hlsearch'
 restore_search_patterns();           // Restore search patterns
 win_size_restore(&cpinfo->save_view);        // Restore window sizes

 ga_clear(&cpinfo->save_view);
 kv_destroy(cpinfo->win_info);
 kv_destroy(cpinfo->buf_info);
}

/// Show 'inccommand' preview if command is previewable. It works like this:
///    1. Store current undo information so we can revert to current state later.
///    2. Execute the preview callback with the parsed command, preview buffer number and preview
///       namespace number as arguments. The preview callback sets the highlight and does the
///       changes required for the preview if needed.
///    3. Preview callback returns 0, 1 or 2. 0 means no preview is shown. 1 means preview is shown
///       but preview window doesn't need to be opened. 2 means preview is shown and preview window
///       needs to be opened if inccommand=split.
///    4. Use the return value of the preview callback to determine whether to
///       open the preview window or not and open preview window if needed.
///    5. If the return value of the preview callback is not 0, update the screen while the effects
///       of the preview are still in place.
///    6. Revert all changes made by the preview callback.
///
/// @return whether preview is shown or not.
static bool cmdpreview_may_show(CommandLineState *s)
{
 // Parse the command line and return if it fails.
 exarg_T ea;
 CmdParseInfo cmdinfo;
 // Copy the command line so we can modify it.
 int cmdpreview_type = 0;
 char *cmdline = xstrdup(ccline.cmdbuff);
 const char *errormsg = NULL;
 emsg_off++;  // Block errors when parsing the command line, and don't update v:errmsg
 if (!parse_cmdline(&cmdline, &ea, &cmdinfo, &errormsg)) {
   emsg_off--;
   goto end;
 }
 emsg_off--;

 // Check if command is previewable, if not, don't attempt to show preview
 if (!(ea.argt & EX_PREVIEW)) {
   undo_cmdmod(&cmdinfo.cmdmod);
   goto end;
 }

 // Cursor may be at the end of the message grid rather than at cmdspos.
 // Place it there in case preview callback flushes it. #30696
 cursorcmd();
 // Flush now: external cmdline may itself wish to update the screen which is
 // currently disallowed during cmdpreview (no longer needed in case that changes).
 cmdline_ui_flush();

 // Swap invalid command range if needed
 if ((ea.argt & EX_RANGE) && ea.line1 > ea.line2) {
   linenr_T lnum = ea.line1;
   ea.line1 = ea.line2;
   ea.line2 = lnum;
 }

 CpInfo cpinfo;
 bool icm_split = *p_icm == 's';  // inccommand=split
 buf_T *cmdpreview_buf = NULL;
 win_T *cmdpreview_win = NULL;

 emsg_silent++;                 // Block error reporting as the command may be incomplete,
                                // but still update v:errmsg
 msg_silent++;                  // Block messages, namely ones that prompt
 block_autocmds();              // Block events

 // Save current state and prepare for command preview.
 cmdpreview_prepare(&cpinfo);

 // Open preview buffer if inccommand=split.
 if (icm_split && (cmdpreview_buf = cmdpreview_open_buf()) == NULL) {
   // Failed to create preview buffer, so disable preview.
   set_option_direct(kOptInccommand, STATIC_CSTR_AS_OPTVAL("nosplit"), 0, SID_NONE);
   icm_split = false;
 }
 // Setup preview namespace if it's not already set.
 if (!cmdpreview_ns) {
   cmdpreview_ns = (int)nvim_create_namespace((String)STRING_INIT);
 }

 // Set cmdpreview state.
 cmdpreview = true;

 // Execute the preview callback and use its return value to determine whether to show preview or
 // open the preview window. The preview callback also handles doing the changes and highlights for
 // the preview.
 Error err = ERROR_INIT;
 TRY_WRAP(&err, {
   cmdpreview_type = execute_cmd(&ea, &cmdinfo, true);
 });
 if (ERROR_SET(&err)) {
   api_clear_error(&err);
   cmdpreview_type = 0;
 }

 // If inccommand=split and preview callback returns 2, open preview window.
 if (icm_split && cmdpreview_type == 2
     && (cmdpreview_win = cmdpreview_open_win(cmdpreview_buf)) == NULL) {
   // If there's not enough room to open the preview window, just preview without the window.
   cmdpreview_type = 1;
 }

 // If preview callback return value is nonzero, update screen now.
 if (cmdpreview_type != 0) {
   int save_rd = RedrawingDisabled;
   RedrawingDisabled = 0;
   update_screen();
   RedrawingDisabled = save_rd;
 }

 // Close preview window if it's open.
 if (icm_split && cmdpreview_type == 2 && cmdpreview_win != NULL) {
   cmdpreview_close_win();
 }

 // Restore state.
 cmdpreview_restore_state(&cpinfo);

 unblock_autocmds();                  // Unblock events
 msg_silent--;                        // Unblock messages
 emsg_silent--;                       // Unblock error reporting
 redrawcmdline();
end:
 xfree(cmdline);
 return cmdpreview_type != 0;
}

/// Trigger CmdlineChanged autocommands.
static void do_autocmd_cmdlinechanged(int firstc)
{
 if (has_event(EVENT_CMDLINECHANGED)) {
   Error err = ERROR_INIT;
   save_v_event_T save_v_event;
   dict_T *dict = get_v_event(&save_v_event);

   char firstcbuf[2];
   firstcbuf[0] = (char)firstc;
   firstcbuf[1] = 0;

   // set v:event to a dictionary with information about the commandline
   tv_dict_add_str(dict, S_LEN("cmdtype"), firstcbuf);
   tv_dict_add_nr(dict, S_LEN("cmdlevel"), ccline.level);
   tv_dict_set_keys_readonly(dict);
   TRY_WRAP(&err, {
     apply_autocmds(EVENT_CMDLINECHANGED, firstcbuf, firstcbuf, false, curbuf);
     restore_v_event(dict, &save_v_event);
   });
   if (ERROR_SET(&err)) {
     if (!ui_has(kUIMessages)) {
       msg_putchar('\n');
     }
     msg_scroll = true;
     msg_puts_hl(err.msg, HLF_E, true);
     api_clear_error(&err);
     redrawcmd();
   }
 }
}

static int command_line_changed(CommandLineState *s)
{
 const bool prev_cmdpreview = cmdpreview;
 if (s->firstc == ':'
     && current_sctx.sc_sid == 0    // only if interactive
     && *p_icm != NUL       // 'inccommand' is set
     && !exmode_active      // not in ex mode
     && cmdline_star == 0   // not typing a password
     && !vpeekc_any()
     && cmdpreview_may_show(s)) {
   // 'inccommand' preview has been shown.
 } else {
   cmdpreview = false;
   if (prev_cmdpreview) {
     // TODO(bfredl): add an immediate redraw flag for cmdline mode which will trigger
     // at next wait-for-input
     update_screen();  // Clear 'inccommand' preview.
   }
   if (s->xpc.xp_context == EXPAND_NOTHING && (KeyTyped || vpeekc() == NUL)) {
     may_do_incsearch_highlighting(s->firstc, s->count, &s->is_state);
   }
 }

 if (ccline.cmdpos != s->prev_cmdpos
     || (s->prev_cmdbuff != NULL && strcmp(s->prev_cmdbuff, ccline.cmdbuff) != 0)) {
   // Trigger CmdlineChanged autocommands.
   do_autocmd_cmdlinechanged(s->firstc > 0 ? s->firstc : '-');
 }

 may_trigger_cursormovedc(s);

 if (p_arshape && !p_tbidi) {
   // Always redraw the whole command line to fix shaping and
   // right-left typing.  Not efficient, but it works.
   // Do it only when there are no characters left to read
   // to avoid useless intermediate redraws.
   // if cmdline is external the ui handles shaping, no redraw needed.
   if (!ui_has(kUICmdline) && vpeekc() == NUL) {
     redrawcmd();
   }
 }

 return 1;
}

/// Abandon the command line.
static void abandon_cmdline(void)
{
 dealloc_cmdbuff();
 if (msg_scrolled == 0) {
   compute_cmdrow();
 }
 // Avoid overwriting key prompt
 if (!ccline.one_key) {
   msg("", 0);
   redraw_cmdline = true;
 }
}

/// getcmdline() - accept a command line starting with firstc.
///
/// firstc == ':'            get ":" command line.
/// firstc == '/' or '?'     get search pattern
/// firstc == '='            get expression
/// firstc == '@'            get text for input() function
/// firstc == '>'            get text for debug mode
/// firstc == NUL            get text for :insert command
/// firstc == -1             like NUL, and break on CTRL-C
///
/// The line is collected in ccline.cmdbuff, which is reallocated to fit the
/// command line.
///
/// Careful: getcmdline() can be called recursively!
///
/// Return pointer to allocated string if there is a commandline, NULL
/// otherwise.
///
/// @param count  only used for incremental search
/// @param indent  indent for inside conditionals
char *getcmdline(int firstc, int count, int indent, bool do_concat FUNC_ATTR_UNUSED)
{
 return (char *)command_line_enter(firstc, count, indent, true);
}

/// Get a command line with a prompt
///
/// This is prepared to be called recursively from getcmdline() (e.g. by
/// f_input() when evaluating an expression from `<C-r>=`).
///
/// @param[in]  firstc  Prompt type: e.g. '@' for input(), '>' for debug.
/// @param[in]  prompt  Prompt string: what is displayed before the user text.
/// @param[in]  hl_id  Prompt highlight id.
/// @param[in]  xp_context  Type of expansion.
/// @param[in]  xp_arg  User-defined expansion argument.
/// @param[in]  highlight_callback  Callback used for highlighting user input.
/// @param[in]  one_key  Return after one key press for button prompt.
/// @param[in]  mouse_used  Set to true when returning after right mouse click.
///
/// @return [allocated] Command line or NULL.
char *getcmdline_prompt(const int firstc, const char *const prompt, const int hl_id,
                       const int xp_context, const char *const xp_arg,
                       const Callback highlight_callback, bool one_key, bool *mouse_used)
 FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_MALLOC
{
 const int msg_col_save = msg_col;

 CmdlineInfo save_ccline;
 bool did_save_ccline = false;
 if (ccline.cmdbuff != NULL) {
   // Save the values of the current cmdline and restore them below.
   save_cmdline(&save_ccline);
   did_save_ccline = true;
 } else {
   CLEAR_FIELD(ccline);
 }
 ccline.prompt_id = last_prompt_id++;
 ccline.cmdprompt = (char *)prompt;
 ccline.hl_id = hl_id;
 ccline.xp_context = xp_context;
 ccline.xp_arg = (char *)xp_arg;
 ccline.input_fn = (firstc == '@');
 ccline.highlight_callback = highlight_callback;
 ccline.one_key = one_key;
 ccline.mouse_used = mouse_used;

 const bool cmd_silent_saved = cmd_silent;
 int msg_silent_saved = msg_silent;
 msg_silent = 0;
 cmd_silent = false;  // Want to see the prompt.

 char *const ret = (char *)command_line_enter(firstc, 1, 0, false);
 ccline.redraw_state = kCmdRedrawNone;

 if (did_save_ccline) {
   restore_cmdline(&save_ccline);
 }
 msg_silent = msg_silent_saved;
 cmd_silent = cmd_silent_saved;
 // Restore msg_col, the prompt from input() may have changed it.
 // But only if called recursively and the commandline is therefore being
 // restored to an old one; if not, the input() prompt stays on the screen,
 // so we need its modified msg_col left intact.
 if (ccline.cmdbuff != NULL) {
   msg_col = msg_col_save;
 }

 return ret;
}

/// Read the 'wildmode' option, fill wim_flags[].
int check_opt_wim(void)
{
 uint8_t new_wim_flags[4];
 int i;
 int idx = 0;

 for (i = 0; i < 4; i++) {
   new_wim_flags[i] = 0;
 }

 for (char *p = p_wim; *p; p++) {
   // Note: Keep this in sync with opt_wim_values.
   for (i = 0; ASCII_ISALPHA(p[i]); i++) {}
   if (p[i] != NUL && p[i] != ',' && p[i] != ':') {
     return FAIL;
   }
   if (i == 7 && strncmp(p, "longest", 7) == 0) {
     new_wim_flags[idx] |= kOptWimFlagLongest;
   } else if (i == 4 && strncmp(p, "full", 4) == 0) {
     new_wim_flags[idx] |= kOptWimFlagFull;
   } else if (i == 4 && strncmp(p, "list", 4) == 0) {
     new_wim_flags[idx] |= kOptWimFlagList;
   } else if (i == 8 && strncmp(p, "lastused", 8) == 0) {
     new_wim_flags[idx] |= kOptWimFlagLastused;
   } else if (i == 8 && strncmp(p, "noselect", 8) == 0) {
     new_wim_flags[idx] |= kOptWimFlagNoselect;
   } else {
     return FAIL;
   }
   p += i;
   if (*p == NUL) {
     break;
   }
   if (*p == ',') {
     if (idx == 3) {
       return FAIL;
     }
     idx++;
   }
 }

 // fill remaining entries with last flag
 while (idx < 3) {
   new_wim_flags[idx + 1] = new_wim_flags[idx];
   idx++;
 }

 // only when there are no errors, wim_flags[] is changed
 for (i = 0; i < 4; i++) {
   wim_flags[i] = new_wim_flags[i];
 }
 return OK;
}

/// Return true when the text must not be changed and we can't switch to
/// another window or buffer.  True when editing the command line etc.
bool text_locked(void)
{
 if (cmdwin_type != 0) {
   return true;
 }
 if (expr_map_locked()) {
   return true;
 }
 return textlock != 0;
}

// Give an error message for a command that isn't allowed while the cmdline
// window is open or editing the cmdline in another way.
void text_locked_msg(void)
{
 emsg(_(get_text_locked_msg()));
}

const char *get_text_locked_msg(void)
{
 if (cmdwin_type != 0) {
   return e_cmdwin;
 } else {
   return e_textlock;
 }
}

/// Check for text, window or buffer locked.
/// Give an error message and return true if something is locked.
bool text_or_buf_locked(void)
{
 if (text_locked()) {
   text_locked_msg();
   return true;
 }
 return curbuf_locked();
}

/// Check if "curbuf->b_ro_locked" or "allbuf_lock" is set and
/// return true when it is and give an error message.
bool curbuf_locked(void)
{
 if (curbuf->b_ro_locked > 0) {
   emsg(_(e_cannot_edit_other_buf));
   return true;
 }
 return allbuf_locked();
}

// Check if "allbuf_lock" is set and return true when it is and give an error
// message.
bool allbuf_locked(void)
{
 if (allbuf_lock > 0) {
   emsg(_("E811: Not allowed to change buffer information now"));
   return true;
 }
 return false;
}

static int cmdline_charsize(int idx)
{
 if (cmdline_star > 0) {           // showing '*', always 1 position
   return 1;
 }
 return ptr2cells(ccline.cmdbuff + idx);
}

/// Compute the offset of the cursor on the command line for the prompt and
/// indent.
static int cmd_startcol(void)
{
 return ccline.cmdindent + ((ccline.cmdfirstc != NUL) ? 1 : 0);
}

/// Compute the column position for a byte position on the command line.
int cmd_screencol(int bytepos)
{
 int m;  // maximum column
 int col = cmd_startcol();
 if (KeyTyped) {
   m = cmdline_win ? cmdline_win->w_view_width * cmdline_win->w_view_height : Columns * Rows;
   if (m < 0) {        // overflow, Columns or Rows at weird value
     m = MAXCOL;
   }
 } else {
   m = MAXCOL;
 }

 for (int i = 0; i < ccline.cmdlen && i < bytepos;
      i += utfc_ptr2len(ccline.cmdbuff + i)) {
   int c = cmdline_charsize(i);
   // Count ">" for double-wide multi-byte char that doesn't fit.
   correct_screencol(i, c, &col);

   // If the cmdline doesn't fit, show cursor on last visible char.
   // Don't move the cursor itself, so we can still append.
   if ((col += c) >= m) {
     col -= c;
     break;
   }
 }
 return col;
}

/// Check if the character at "idx", which is "cells" wide, is a multi-byte
/// character that doesn't fit, so that a ">" must be displayed.
static void correct_screencol(int idx, int cells, int *col)
{
 if (utfc_ptr2len(ccline.cmdbuff + idx) > 1
     && utf_ptr2cells(ccline.cmdbuff + idx) > 1
     && (*col) % Columns + cells > Columns) {
   (*col)++;
 }
}

/// Get an Ex command line for the ":" command.
///
/// @param c  normally ':', NUL for ":append"
/// @param indent  indent for inside conditionals
char *getexline(int c, void *cookie, int indent, bool do_concat)
{
 // When executing a register, remove ':' that's in front of each line.
 if (exec_from_reg && vpeekc() == ':') {
   vgetc();
 }

 return getcmdline(c, 1, indent, do_concat);
}

bool cmdline_overstrike(void)
 FUNC_ATTR_PURE
{
 return ccline.overstrike;
}

/// Return true if the cursor is at the end of the cmdline.
bool cmdline_at_end(void)
 FUNC_ATTR_PURE
{
 return (ccline.cmdpos >= ccline.cmdlen);
}

/// Deallocate a command line buffer, updating the buffer size and length.
static void dealloc_cmdbuff(void)
{
 XFREE_CLEAR(ccline.cmdbuff);
 ccline.cmdlen = ccline.cmdbufflen = 0;
}

/// Allocate a new command line buffer.
/// Assigns the new buffer to ccline.cmdbuff and ccline.cmdbufflen.
static void alloc_cmdbuff(int len)
{
 // give some extra space to avoid having to allocate all the time
 if (len < 80) {
   len = 100;
 } else {
   len += 20;
 }

 ccline.cmdbuff = xmalloc((size_t)len);
 ccline.cmdbufflen = len;
}

/// Re-allocate the command line to length len + something extra.
void realloc_cmdbuff(int len)
{
 if (len < ccline.cmdbufflen) {
   return;  // no need to resize
 }

 char *p = ccline.cmdbuff;

 alloc_cmdbuff(len);                   // will get some more
 // There isn't always a NUL after the command, but it may need to be
 // there, thus copy up to the NUL and add a NUL.
 memmove(ccline.cmdbuff, p, (size_t)ccline.cmdlen);
 ccline.cmdbuff[ccline.cmdlen] = NUL;

 if (ccline.xpc != NULL
     && ccline.xpc->xp_pattern != NULL
     && ccline.xpc->xp_context != EXPAND_NOTHING
     && ccline.xpc->xp_context != EXPAND_UNSUCCESSFUL) {
   int i = (int)(ccline.xpc->xp_pattern - p);

   // If xp_pattern points inside the old cmdbuff it needs to be adjusted
   // to point into the newly allocated memory.
   if (i >= 0 && i <= ccline.cmdlen) {
     ccline.xpc->xp_pattern = ccline.cmdbuff + i;
   }
 }

 xfree(p);
}

enum { MAX_CB_ERRORS = 1, };

/// Color expression cmdline using built-in expressions parser
///
/// @param[in]  colored_ccline  Command-line to color.
/// @param[out]  ret_ccline_colors  What should be colored.
///
/// Always colors the whole cmdline.
static void color_expr_cmdline(const CmdlineInfo *const colored_ccline,
                              ColoredCmdline *const ret_ccline_colors)
 FUNC_ATTR_NONNULL_ALL
{
 ParserLine parser_lines[] = {
   {
     .data = colored_ccline->cmdbuff,
     .size = strlen(colored_ccline->cmdbuff),
     .allocated = false,
   },
   { NULL, 0, false },
 };
 ParserLine *plines_p = parser_lines;
 ParserHighlight colors;
 kvi_init(colors);
 ParserState pstate;
 viml_parser_init(&pstate, parser_simple_get_line, &plines_p, &colors);
 ExprAST east = viml_pexpr_parse(&pstate, kExprFlagsDisallowEOC);
 viml_pexpr_free_ast(east);
 viml_parser_destroy(&pstate);
 kv_resize(ret_ccline_colors->colors, kv_size(colors));
 size_t prev_end = 0;
 for (size_t i = 0; i < kv_size(colors); i++) {
   const ParserHighlightChunk chunk = kv_A(colors, i);
   assert(chunk.start.col < INT_MAX);
   assert(chunk.end_col < INT_MAX);
   if (chunk.start.col != prev_end) {
     kv_push(ret_ccline_colors->colors, ((CmdlineColorChunk) {
       .start = (int)prev_end,
       .end = (int)chunk.start.col,
       .hl_id = 0,
     }));
   }
   kv_push(ret_ccline_colors->colors, ((CmdlineColorChunk) {
     .start = (int)chunk.start.col,
     .end = (int)chunk.end_col,
     .hl_id = syn_name2id(chunk.group),
   }));
   prev_end = chunk.end_col;
 }
 if (prev_end < (size_t)colored_ccline->cmdlen) {
   kv_push(ret_ccline_colors->colors, ((CmdlineColorChunk) {
     .start = (int)prev_end,
     .end = colored_ccline->cmdlen,
     .hl_id = 0,
   }));
 }
 kvi_destroy(colors);
}

/// Color command-line
///
/// Should use built-in command parser or user-specified one. Currently only the
/// latter is supported.
///
/// @param[in,out]  colored_ccline  Command-line to color. Also holds a cache:
///                                 if ->prompt_id and ->cmdbuff values happen
///                                 to be equal to those from colored_cmdline it
///                                 will just do nothing, assuming that ->colors
///                                 already contains needed data.
///
/// Always colors the whole cmdline.
///
/// @return true if draw_cmdline may proceed, false if it does not need anything
///         to do.
static bool color_cmdline(CmdlineInfo *colored_ccline)
 FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
{
 bool printed_errmsg = false;

#define PRINT_ERRMSG(...) \
 do { \
   msg_scroll = true; \
   msg_putchar('\n'); \
   smsg(HLF_E, __VA_ARGS__); \
   printed_errmsg = true; \
 } while (0)
 bool ret = true;

 ColoredCmdline *ccline_colors = &colored_ccline->last_colors;

 // Check whether result of the previous call is still valid.
 if (ccline_colors->prompt_id == colored_ccline->prompt_id
     && ccline_colors->cmdbuff != NULL
     && strcmp(ccline_colors->cmdbuff, colored_ccline->cmdbuff) == 0) {
   return ret;
 }

 kv_size(ccline_colors->colors) = 0;

 if (colored_ccline->cmdbuff == NULL || *colored_ccline->cmdbuff == NUL) {
   // Nothing to do, exiting.
   XFREE_CLEAR(ccline_colors->cmdbuff);
   return ret;
 }

 bool arg_allocated = false;
 typval_T arg = {
   .v_type = VAR_STRING,
   .vval.v_string = colored_ccline->cmdbuff,
 };
 typval_T tv = { .v_type = VAR_UNKNOWN };

 static unsigned prev_prompt_id = UINT_MAX;
 static int prev_prompt_errors = 0;
 Callback color_cb = CALLBACK_NONE;
 bool can_free_cb = false;
 Error err = ERROR_INIT;
 const char *err_errmsg = e_intern2;
 bool dgc_ret = true;

 if (colored_ccline->prompt_id != prev_prompt_id) {
   prev_prompt_errors = 0;
   prev_prompt_id = colored_ccline->prompt_id;
 } else if (prev_prompt_errors >= MAX_CB_ERRORS) {
   goto color_cmdline_end;
 }
 if (colored_ccline->highlight_callback.type != kCallbackNone) {
   // Currently this should only happen while processing input() prompts.
   assert(colored_ccline->input_fn);
   color_cb = colored_ccline->highlight_callback;
 } else if (colored_ccline->cmdfirstc == ':') {
   TRY_WRAP(&err, {
     err_errmsg = N_("E5408: Unable to get g:Nvim_color_cmdline callback: %s");
     dgc_ret = tv_dict_get_callback(get_globvar_dict(), S_LEN("Nvim_color_cmdline"),
                                    &color_cb);
   });
   can_free_cb = true;
 } else if (colored_ccline->cmdfirstc == '=') {
   color_expr_cmdline(colored_ccline, ccline_colors);
 }
 if (ERROR_SET(&err) || !dgc_ret) {
   goto color_cmdline_error;
 }

 if (color_cb.type == kCallbackNone) {
   goto color_cmdline_end;
 }
 if (colored_ccline->cmdbuff[colored_ccline->cmdlen] != NUL) {
   arg_allocated = true;
   arg.vval.v_string = xmemdupz(colored_ccline->cmdbuff, (size_t)colored_ccline->cmdlen);
 }
 // msg_start() called by e.g. :echo may shift command-line to the first column
 // even though msg_silent is here. Two ways to workaround this problem without
 // altering message.c: use full_screen or save and restore msg_col.
 //
 // Saving and restoring full_screen does not work well with :redraw!. Saving
 // and restoring msg_col is neither ideal, but while with full_screen it
 // appears shifted one character to the right and cursor position is no longer
 // correct, with msg_col it just misses leading `:`. Since `redraw!` in
 // callback lags this is least of the user problems.
 //
 // Also using TRY_WRAP because error messages may overwrite typed
 // command-line which is not expected.
 getln_interrupted_highlight = false;
 bool cbcall_ret = true;
 TRY_WRAP(&err, {
   err_errmsg = N_("E5407: Callback has thrown an exception: %s");
   const int saved_msg_col = msg_col;
   msg_silent++;
   cbcall_ret = callback_call(&color_cb, 1, &arg, &tv);
   msg_silent--;
   msg_col = saved_msg_col;
   if (got_int) {
     getln_interrupted_highlight = true;
   }
 });
 if (ERROR_SET(&err) || !cbcall_ret) {
   goto color_cmdline_error;
 }
 if (tv.v_type != VAR_LIST) {
   PRINT_ERRMSG("%s", _("E5400: Callback should return list"));
   goto color_cmdline_error;
 }
 if (tv.vval.v_list == NULL) {
   goto color_cmdline_end;
 }
 varnumber_T prev_end = 0;
 int i = 0;
 TV_LIST_ITER_CONST(tv.vval.v_list, li, {
   if (TV_LIST_ITEM_TV(li)->v_type != VAR_LIST) {
     PRINT_ERRMSG(_("E5401: List item %i is not a List"), i);
     goto color_cmdline_error;
   }
   const list_T *const l = TV_LIST_ITEM_TV(li)->vval.v_list;
   if (tv_list_len(l) != 3) {
     PRINT_ERRMSG(_("E5402: List item %i has incorrect length: %d /= 3"),
                  i, tv_list_len(l));
     goto color_cmdline_error;
   }
   bool error = false;
   const varnumber_T start = (
                              tv_get_number_chk(TV_LIST_ITEM_TV(tv_list_first(l)), &error));
   if (error) {
     goto color_cmdline_error;
   } else if (!(prev_end <= start && start < colored_ccline->cmdlen)) {
     PRINT_ERRMSG(_("E5403: Chunk %i start %" PRIdVARNUMBER " not in range "
                    "[%" PRIdVARNUMBER ", %i)"),
                  i, start, prev_end, colored_ccline->cmdlen);
     goto color_cmdline_error;
   } else if (utf8len_tab_zero[(uint8_t)colored_ccline->cmdbuff[start]] == 0) {
     PRINT_ERRMSG(_("E5405: Chunk %i start %" PRIdVARNUMBER " splits "
                    "multibyte character"), i, start);
     goto color_cmdline_error;
   }
   if (start != prev_end) {
     kv_push(ccline_colors->colors, ((CmdlineColorChunk) {
       .start = (int)prev_end,
       .end = (int)start,
       .hl_id = 0,
     }));
   }
   const varnumber_T end =
     tv_get_number_chk(TV_LIST_ITEM_TV(TV_LIST_ITEM_NEXT(l, tv_list_first(l))), &error);
   if (error) {
     goto color_cmdline_error;
   } else if (!(start < end && end <= colored_ccline->cmdlen)) {
     PRINT_ERRMSG(_("E5404: Chunk %i end %" PRIdVARNUMBER " not in range "
                    "(%" PRIdVARNUMBER ", %i]"),
                  i, end, start, colored_ccline->cmdlen);
     goto color_cmdline_error;
   } else if (end < colored_ccline->cmdlen
              && (utf8len_tab_zero[(uint8_t)colored_ccline->cmdbuff[end]]
                  == 0)) {
     PRINT_ERRMSG(_("E5406: Chunk %i end %" PRIdVARNUMBER " splits multibyte "
                    "character"), i, end);
     goto color_cmdline_error;
   }
   prev_end = end;
   const char *const group = tv_get_string_chk(TV_LIST_ITEM_TV(tv_list_last(l)));
   if (group == NULL) {
     goto color_cmdline_error;
   }
   kv_push(ccline_colors->colors, ((CmdlineColorChunk) {
     .start = (int)start,
     .end = (int)end,
     .hl_id = syn_name2id(group),
   }));
   i++;
 });
 if (prev_end < colored_ccline->cmdlen) {
   kv_push(ccline_colors->colors, ((CmdlineColorChunk) {
     .start = (int)prev_end,
     .end = colored_ccline->cmdlen,
     .hl_id = 0,
   }));
 }
 prev_prompt_errors = 0;
color_cmdline_end:
 assert(!ERROR_SET(&err));
 if (can_free_cb) {
   callback_free(&color_cb);
 }
 xfree(ccline_colors->cmdbuff);
 // Note: errors “output” is cached just as well as regular results.
 ccline_colors->prompt_id = colored_ccline->prompt_id;
 if (arg_allocated) {
   ccline_colors->cmdbuff = arg.vval.v_string;
 } else {
   ccline_colors->cmdbuff = xmemdupz(colored_ccline->cmdbuff, (size_t)colored_ccline->cmdlen);
 }
 tv_clear(&tv);
 return ret;
color_cmdline_error:
 if (ERROR_SET(&err)) {
   PRINT_ERRMSG(_(err_errmsg), err.msg);
   api_clear_error(&err);
 }
 assert(printed_errmsg);
 (void)printed_errmsg;

 prev_prompt_errors++;
 kv_size(ccline_colors->colors) = 0;
 redrawcmdline();
 ret = false;
 goto color_cmdline_end;
#undef PRINT_ERRMSG
}

// Draw part of the cmdline at the current cursor position.  But draw stars
// when cmdline_star is true.
static void draw_cmdline(int start, int len)
{
 if (ccline.cmdbuff == NULL || !color_cmdline(&ccline)) {
   return;
 }

 if (ui_has(kUICmdline)) {
   ccline.special_char = NUL;
   ccline.redraw_state = kCmdRedrawAll;
   return;
 }

 if (cmdline_star > 0) {
   for (int i = 0; i < len; i++) {
     msg_putchar('*');
     i += utfc_ptr2len(ccline.cmdbuff + start + i) - 1;
   }
 } else {
   if (kv_size(ccline.last_colors.colors)) {
     for (size_t i = 0; i < kv_size(ccline.last_colors.colors); i++) {
       CmdlineColorChunk chunk = kv_A(ccline.last_colors.colors, i);
       if (chunk.end <= start) {
         continue;
       }
       const int chunk_start = MAX(chunk.start, start);
       msg_outtrans_len(ccline.cmdbuff + chunk_start, chunk.end - chunk_start, chunk.hl_id, false);
     }
   } else {
     msg_outtrans_len(ccline.cmdbuff + start, len, 0, false);
   }
 }
}

static void ui_ext_cmdline_show(CmdlineInfo *line)
{
 Arena arena = ARENA_EMPTY;
 Array content;
 if (cmdline_star) {
   content = arena_array(&arena, 1);
   size_t len = 0;
   for (char *p = ccline.cmdbuff; *p; MB_PTR_ADV(p)) {
     len++;
   }
   char *buf = arena_alloc(&arena, len, false);
   memset(buf, '*', len);
   Array item = arena_array(&arena, 3);
   ADD_C(item, INTEGER_OBJ(0));
   ADD_C(item, STRING_OBJ(cbuf_as_string(buf, len)));
   ADD_C(item, INTEGER_OBJ(0));
   ADD_C(content, ARRAY_OBJ(item));
 } else if (kv_size(line->last_colors.colors)) {
   content = arena_array(&arena, kv_size(line->last_colors.colors));
   for (size_t i = 0; i < kv_size(line->last_colors.colors); i++) {
     CmdlineColorChunk chunk = kv_A(line->last_colors.colors, i);
     Array item = arena_array(&arena, 3);
     ADD_C(item, INTEGER_OBJ(chunk.hl_id == 0 ? 0 : syn_id2attr(chunk.hl_id)));

     assert(chunk.end >= chunk.start);
     ADD_C(item, STRING_OBJ(cbuf_as_string(line->cmdbuff + chunk.start,
                                           (size_t)(chunk.end - chunk.start))));
     ADD_C(item, INTEGER_OBJ(chunk.hl_id));
     ADD_C(content, ARRAY_OBJ(item));
   }
 } else {
   Array item = arena_array(&arena, 3);
   ADD_C(item, INTEGER_OBJ(0));
   ADD_C(item, CSTR_AS_OBJ(line->cmdbuff));
   ADD_C(item, INTEGER_OBJ(0));
   content = arena_array(&arena, 1);
   ADD_C(content, ARRAY_OBJ(item));
 }
 char charbuf[2] = { (char)line->cmdfirstc, 0 };
 ui_call_cmdline_show(content, line->cmdpos,
                      cstr_as_string(charbuf),
                      cstr_as_string((line->cmdprompt)),
                      line->cmdindent, line->level, line->hl_id);
 if (line->special_char) {
   charbuf[0] = line->special_char;
   ui_call_cmdline_special_char(cstr_as_string(charbuf),
                                line->special_shift,
                                line->level);
 }
 arena_mem_free(arena_finish(&arena));
}

void ui_ext_cmdline_block_append(size_t indent, const char *line)
{
 char *buf = xmallocz(indent + strlen(line));
 memset(buf, ' ', indent);
 memcpy(buf + indent, line, strlen(line));

 Array item = ARRAY_DICT_INIT;
 ADD(item, INTEGER_OBJ(0));
 ADD(item, CSTR_AS_OBJ(buf));
 ADD(item, INTEGER_OBJ(0));
 Array content = ARRAY_DICT_INIT;
 ADD(content, ARRAY_OBJ(item));
 ADD(cmdline_block, ARRAY_OBJ(content));
 if (cmdline_block.size > 1) {
   ui_call_cmdline_block_append(content);
 } else {
   ui_call_cmdline_block_show(cmdline_block);
 }
}

void ui_ext_cmdline_block_leave(void)
{
 api_free_array(cmdline_block);
 cmdline_block = (Array)ARRAY_DICT_INIT;
 ui_call_cmdline_block_hide();
}

/// Extra redrawing needed for redraw! and on ui_attach.
void cmdline_screen_cleared(void)
{
 if (!ui_has(kUICmdline)) {
   return;
 }

 if (cmdline_block.size) {
   ui_call_cmdline_block_show(cmdline_block);
 }

 int prev_level = ccline.level - 1;
 CmdlineInfo *line = ccline.prev_ccline;
 while (prev_level > 0 && line) {
   if (line->level == prev_level) {
     // don't redraw a cmdline already shown in the cmdline window
     if (prev_level != cmdwin_level) {
       line->redraw_state = kCmdRedrawAll;
     }
     prev_level--;
   }
   line = line->prev_ccline;
 }
 redrawcmd();
}

/// called by ui_flush, do what redraws necessary to keep cmdline updated.
void cmdline_ui_flush(void)
{
 if (!ui_has(kUICmdline)) {
   return;
 }
 int level = ccline.level;
 CmdlineInfo *line = &ccline;
 while (level > 0 && line) {
   if (line->level == level) {
     CmdRedraw redraw_state = line->redraw_state;
     line->redraw_state = kCmdRedrawNone;
     if (redraw_state == kCmdRedrawAll) {
       cmdline_was_last_drawn = true;
       ui_ext_cmdline_show(line);
     } else if (redraw_state == kCmdRedrawPos && cmdline_was_last_drawn) {
       ui_call_cmdline_pos(line->cmdpos, line->level);
     }
     level--;
   }
   line = line->prev_ccline;
 }
}

// Put a character on the command line.  Shifts the following text to the
// right when "shift" is true.  Used for CTRL-V, CTRL-K, etc.
// "c" must be printable (fit in one display cell)!
void putcmdline(char c, bool shift)
{
 if (cmd_silent) {
   return;
 }
 if (!ui_has(kUICmdline)) {
   msg_no_more = true;
   msg_putchar(c);
   if (shift) {
     draw_cmdline(ccline.cmdpos, ccline.cmdlen - ccline.cmdpos);
   }
   msg_no_more = false;
 } else if (ccline.redraw_state != kCmdRedrawAll) {
   char charbuf[2] = { c, 0 };
   ui_call_cmdline_special_char(cstr_as_string(charbuf), shift,
                                ccline.level);
 }
 cursorcmd();
 ccline.special_char = c;
 ccline.special_shift = shift;
 ui_cursor_shape();
}

/// Undo a putcmdline(c, false).
void unputcmdline(void)
{
 if (cmd_silent) {
   return;
 }
 msg_no_more = true;
 if (ccline.cmdlen == ccline.cmdpos && !ui_has(kUICmdline)) {
   msg_putchar(' ');
 } else {
   draw_cmdline(ccline.cmdpos, utfc_ptr2len(ccline.cmdbuff + ccline.cmdpos));
 }
 msg_no_more = false;
 cursorcmd();
 ccline.special_char = NUL;
 ui_cursor_shape();
}

// Put the given string, of the given length, onto the command line.
// If len is -1, then strlen() is used to calculate the length.
// If 'redraw' is true then the new part of the command line, and the remaining
// part will be redrawn, otherwise it will not.  If this function is called
// twice in a row, then 'redraw' should be false and redrawcmd() should be
// called afterwards.
void put_on_cmdline(const char *str, int len, bool redraw)
{
 if (len < 0) {
   len = (int)strlen(str);
 }

 realloc_cmdbuff(ccline.cmdlen + len + 1);

 if (!ccline.overstrike) {
   memmove(ccline.cmdbuff + ccline.cmdpos + len,
           ccline.cmdbuff + ccline.cmdpos,
           (size_t)(ccline.cmdlen - ccline.cmdpos));
   ccline.cmdlen += len;
 } else {
   // Count nr of characters in the new string.
   int m = 0;
   int i;
   for (i = 0; i < len; i += utfc_ptr2len(str + i)) {
     m++;
   }
   // Count nr of bytes in cmdline that are overwritten by these
   // characters.
   for (i = ccline.cmdpos; i < ccline.cmdlen && m > 0;
        i += utfc_ptr2len(ccline.cmdbuff + i)) {
     m--;
   }
   if (i < ccline.cmdlen) {
     memmove(ccline.cmdbuff + ccline.cmdpos + len,
             ccline.cmdbuff + i, (size_t)(ccline.cmdlen - i));
     ccline.cmdlen += ccline.cmdpos + len - i;
   } else {
     ccline.cmdlen = ccline.cmdpos + len;
   }
 }
 memmove(ccline.cmdbuff + ccline.cmdpos, str, (size_t)len);
 ccline.cmdbuff[ccline.cmdlen] = NUL;

 // When the inserted text starts with a composing character,
 // backup to the character before it.
 if (ccline.cmdpos > 0 && (uint8_t)ccline.cmdbuff[ccline.cmdpos] >= 0x80) {
   int i = utf_head_off(ccline.cmdbuff, ccline.cmdbuff + ccline.cmdpos);
   if (i != 0) {
     ccline.cmdpos -= i;
     len += i;
     ccline.cmdspos = cmd_screencol(ccline.cmdpos);
   }
 }

 if (redraw && !cmd_silent) {
   msg_no_more = true;
   int i = cmdline_row;
   cursorcmd();
   draw_cmdline(ccline.cmdpos, ccline.cmdlen - ccline.cmdpos);
   // Avoid clearing the rest of the line too often.
   if (cmdline_row != i || ccline.overstrike) {
     msg_clr_eos();
   }
   msg_no_more = false;
 }
 int m;
 if (KeyTyped) {
   m = Columns * Rows;
   if (m < 0) {            // overflow, Columns or Rows at weird value
     m = MAXCOL;
   }
 } else {
   m = MAXCOL;
 }
 for (int i = 0; i < len; i++) {
   int c = cmdline_charsize(ccline.cmdpos);
   // count ">" for a double-wide char that doesn't fit.
   correct_screencol(ccline.cmdpos, c, &ccline.cmdspos);
   // Stop cursor at the end of the screen, but do increment the
   // insert position, so that entering a very long command
   // works, even though you can't see it.
   if (ccline.cmdspos + c < m) {
     ccline.cmdspos += c;
   }
   c = utfc_ptr2len(ccline.cmdbuff + ccline.cmdpos) - 1;
   c = MIN(c, len - i - 1);
   ccline.cmdpos += c;
   i += c;
   ccline.cmdpos++;
 }

 if (redraw) {
   msg_check();
 }
}

/// Save ccline, because obtaining the "=" register may execute "normal :cmd"
/// and overwrite it.
static void save_cmdline(CmdlineInfo *ccp)
{
 *ccp = ccline;
 CLEAR_FIELD(ccline);
 ccline.prev_ccline = ccp;
 ccline.cmdbuff = NULL;  // signal that ccline is not in use
}

/// Restore ccline after it has been saved with save_cmdline().
static void restore_cmdline(CmdlineInfo *ccp)
 FUNC_ATTR_NONNULL_ALL
{
 ccline = *ccp;
}

/// Paste a yank register into the command line.
/// Used by CTRL-R command in command-line mode.
/// insert_reg() can't be used here, because special characters from the
/// register contents will be interpreted as commands.
///
/// @param regname   Register name.
/// @param literally Insert text literally instead of "as typed".
/// @param remcr     When true, remove trailing CR.
///
/// @returns FAIL for failure, OK otherwise
static bool cmdline_paste(int regname, bool literally, bool remcr)
{
 char *arg;
 bool allocated;

 // check for valid regname; also accept special characters for CTRL-R in
 // the command line
 if (regname != Ctrl_F && regname != Ctrl_P && regname != Ctrl_W
     && regname != Ctrl_A && regname != Ctrl_L
     && !valid_yank_reg(regname, false)) {
   return FAIL;
 }

 // A register containing CTRL-R can cause an endless loop.  Allow using
 // CTRL-C to break the loop.
 line_breakcheck();
 if (got_int) {
   return FAIL;
 }

 // Need to  set "textlock" to avoid nasty things like going to another
 // buffer when evaluating an expression.
 textlock++;
 const bool i = get_spec_reg(regname, &arg, &allocated, true);
 textlock--;

 if (i) {
   // Got the value of a special register in "arg".
   if (arg == NULL) {
     return FAIL;
   }

   // When 'incsearch' is set and CTRL-R CTRL-W used: skip the duplicate
   // part of the word.
   char *p = arg;
   if (p_is && regname == Ctrl_W) {
     char *w;
     int len;

     // Locate start of last word in the cmd buffer.
     for (w = ccline.cmdbuff + ccline.cmdpos; w > ccline.cmdbuff;) {
       len = utf_head_off(ccline.cmdbuff, w - 1) + 1;
       if (!vim_iswordc(utf_ptr2char(w - len))) {
         break;
       }
       w -= len;
     }
     len = (int)((ccline.cmdbuff + ccline.cmdpos) - w);
     if (p_ic ? STRNICMP(w, arg, len) == 0 : strncmp(w, arg, (size_t)len) == 0) {
       p += len;
     }
   }

   cmdline_paste_str(p, literally);
   if (allocated) {
     xfree(arg);
   }
   return OK;
 }

 return cmdline_paste_reg(regname, literally, remcr);
}

// Put a string on the command line.
// When "literally" is true, insert literally.
// When "literally" is false, insert as typed, but don't leave the command
// line.
void cmdline_paste_str(const char *s, bool literally)
{
 if (literally) {
   put_on_cmdline(s, -1, true);
 } else {
   while (*s != NUL) {
     int cv = (uint8_t)(*s);
     if (cv == Ctrl_V && s[1]) {
       s++;
     }
     int c = mb_cptr2char_adv(&s);
     if (cv == Ctrl_V || c == ESC || c == Ctrl_C
         || c == CAR || c == NL || c == Ctrl_L
         || (c == Ctrl_BSL && *s == Ctrl_N)) {
       stuffcharReadbuff(Ctrl_V);
     }
     stuffcharReadbuff(c);
   }
 }
}

// This function is called when the screen size changes and with incremental
// search and in other situations where the command line may have been
// overwritten.
void redrawcmdline(void)
{
 if (cmd_silent) {
   return;
 }
 need_wait_return = false;
 compute_cmdrow();
 redrawcmd();
 cursorcmd();
 ui_cursor_shape();
}

static void redrawcmdprompt(void)
{
 if (cmd_silent) {
   return;
 }
 if (ui_has(kUICmdline)) {
   ccline.redraw_state = kCmdRedrawAll;
   return;
 }
 if (ccline.cmdfirstc != NUL) {
   msg_putchar(ccline.cmdfirstc);
 }
 if (ccline.cmdprompt != NULL) {
   msg_puts_hl(ccline.cmdprompt, ccline.hl_id, false);
   ccline.cmdindent = msg_col + (msg_row - cmdline_row) * Columns;
   // do the reverse of cmd_startcol()
   if (ccline.cmdfirstc != NUL) {
     ccline.cmdindent--;
   }
 } else {
   for (int i = ccline.cmdindent; i > 0; i--) {
     msg_putchar(' ');
   }
 }
}

// Redraw what is currently on the command line.
void redrawcmd(void)
{
 if (cmd_silent) {
   return;
 }

 if (ui_has(kUICmdline)) {
   draw_cmdline(0, ccline.cmdlen);
   return;
 }

 // when 'incsearch' is set there may be no command line while redrawing
 if (ccline.cmdbuff == NULL) {
   msg_cursor_goto(cmdline_row, 0);
   msg_clr_eos();
   return;
 }

 redrawing_cmdline = true;

 sb_text_restart_cmdline();
 msg_start();
 redrawcmdprompt();

 // Don't use more prompt, truncate the cmdline if it doesn't fit.
 msg_no_more = true;
 draw_cmdline(0, ccline.cmdlen);
 msg_clr_eos();
 msg_no_more = false;

 ccline.cmdspos = cmd_screencol(ccline.cmdpos);

 if (ccline.special_char != NUL) {
   putcmdline(ccline.special_char, ccline.special_shift);
 }

 // An emsg() before may have set msg_scroll. This is used in normal mode,
 // in cmdline mode we can reset them now.
 msg_scroll = false;           // next message overwrites cmdline

 // Typing ':' at the more prompt may set skip_redraw.  We don't want this
 // in cmdline mode.
 skip_redraw = false;

 redrawing_cmdline = false;
}

void compute_cmdrow(void)
{
 if (exmode_active || msg_scrolled != 0) {
   cmdline_row = Rows - 1;
 } else {
   win_T *wp = lastwin_nofloating();
   cmdline_row = wp->w_winrow + wp->w_height
                 + wp->w_hsep_height + wp->w_status_height + global_stl_height();
 }
 if (cmdline_row == Rows && p_ch > 0) {
   cmdline_row--;
 }
 lines_left = cmdline_row;
}

void cursorcmd(void)
{
 if (cmd_silent || ui_has(kUICmdline)) {
   return;
 }

 msg_row = cmdline_row + (ccline.cmdspos / Columns);
 msg_col = ccline.cmdspos % Columns;
 msg_row = MIN(msg_row, Rows - 1);

 msg_cursor_goto(msg_row, msg_col);
}

void gotocmdline(bool clr)
{
 if (ui_has(kUICmdline)) {
   return;
 }
 msg_start();
 msg_col = 0;  // always start in column 0
 if (clr) {  // clear the bottom line(s)
   msg_clr_eos();  // will reset clear_cmdline
 }
 msg_cursor_goto(cmdline_row, 0);
}

// Check the word in front of the cursor for an abbreviation.
// Called when the non-id character "c" has been entered.
// When an abbreviation is recognized it is removed from the text with
// backspaces and the replacement string is inserted, followed by "c".
static int ccheck_abbr(int c)
{
 int spos = 0;

 if (p_paste || no_abbr) {         // no abbreviations or in paste mode
   return false;
 }

 // Do not consider '<,'> be part of the mapping, skip leading whitespace.
 // Actually accepts any mark.
 while (spos < ccline.cmdlen && ascii_iswhite(ccline.cmdbuff[spos])) {
   spos++;
 }
 if (ccline.cmdlen - spos > 5
     && ccline.cmdbuff[spos] == '\''
     && ccline.cmdbuff[spos + 2] == ','
     && ccline.cmdbuff[spos + 3] == '\'') {
   spos += 5;
 } else {
   // check abbreviation from the beginning of the commandline
   spos = 0;
 }

 return check_abbr(c, ccline.cmdbuff, ccline.cmdpos, spos);
}

/// Escape special characters in "fname", depending on "what":
///
/// @param[in]  fname  File name to escape.
/// @param[in]  what   What to escape for:
/// - VSE_NONE: for when used as a file name argument after a Vim command.
/// - VSE_SHELL: for a shell command.
/// - VSE_BUFFER: for the ":buffer" command.
///
/// @return [allocated] escaped file name.
char *vim_strsave_fnameescape(const char *const fname, const int what)
 FUNC_ATTR_NONNULL_RET FUNC_ATTR_MALLOC FUNC_ATTR_NONNULL_ALL
{
#ifdef BACKSLASH_IN_FILENAME
# define PATH_ESC_CHARS " \t\n*?[{`%#'\"|!<"
# define BUFFER_ESC_CHARS (" \t\n*?[`%#'\"|!<")
 char buf[sizeof(PATH_ESC_CHARS)];
 int j = 0;

 // Don't escape '[', '{' and '!' if they are in 'isfname' and for the
 // ":buffer" command.
 for (const char *p = what == VSE_BUFFER ? BUFFER_ESC_CHARS : PATH_ESC_CHARS;
      *p != NUL; p++) {
   if ((*p != '[' && *p != '{' && *p != '!') || !vim_isfilec((uint8_t)(*p))) {
     buf[j++] = *p;
   }
 }
 buf[j] = NUL;
 char *p = vim_strsave_escaped(fname, buf);
#else
# define PATH_ESC_CHARS " \t\n*?[{`$\\%#'\"|!<"
# define SHELL_ESC_CHARS " \t\n*?[{`$\\%#'\"|!<>();&"
# define BUFFER_ESC_CHARS " \t\n*?[`$\\%#'\"|!<"
 char *p = vim_strsave_escaped(fname,
                               what == VSE_SHELL ? SHELL_ESC_CHARS : what ==
                               VSE_BUFFER ? BUFFER_ESC_CHARS : PATH_ESC_CHARS);
 if (what == VSE_SHELL && csh_like_shell()) {
   // For csh and similar shells need to put two backslashes before '!'.
   // One is taken by Vim, one by the shell.
   char *s = vim_strsave_escaped(p, "!");
   xfree(p);
   p = s;
 }
#endif

 // '>' and '+' are special at the start of some commands, e.g. ":edit" and
 // ":write".  "cd -" has a special meaning.
 if (*p == '>' || *p == '+' || (*p == '-' && p[1] == NUL)) {
   escape_fname(&p);
 }

 return p;
}

/// Put a backslash before the file name in "pp", which is in allocated memory.
void escape_fname(char **pp)
{
 char *p = xmalloc(strlen(*pp) + 2);
 p[0] = '\\';
 STRCPY(p + 1, *pp);
 xfree(*pp);
 *pp = p;
}

/// For each file name in files[num_files]:
/// If 'orig_pat' starts with "~/", replace the home directory with "~".
void tilde_replace(char *orig_pat, int num_files, char **files)
{
 if (orig_pat[0] == '~' && vim_ispathsep(orig_pat[1])) {
   for (int i = 0; i < num_files; i++) {
     char *p = home_replace_save(NULL, files[i]);
     xfree(files[i]);
     files[i] = p;
   }
 }
}

/// Get a pointer to the current command line info.
CmdlineInfo *get_cmdline_info(void)
{
 return &ccline;
}

unsigned get_cmdline_last_prompt_id(void)
{
 return last_prompt_id;
}

/// Get pointer to the command line info to use. save_cmdline() may clear
/// ccline and put the previous value in ccline.prev_ccline.
static CmdlineInfo *get_ccline_ptr(void)
{
 if ((State & MODE_CMDLINE) == 0) {
   return NULL;
 } else if (ccline.cmdbuff != NULL) {
   return &ccline;
 } else if (ccline.prev_ccline && ccline.prev_ccline->cmdbuff != NULL) {
   return ccline.prev_ccline;
 } else {
   return NULL;
 }
}

/// Get the current command-line type.
/// Returns ':' or '/' or '?' or '@' or '>' or '-'
/// Only works when the command line is being edited.
/// Returns NUL when something is wrong.
static int get_cmdline_type(void)
{
 CmdlineInfo *p = get_ccline_ptr();

 if (p == NULL) {
   return NUL;
 }
 if (p->cmdfirstc == NUL) {
   return (p->input_fn) ? '@' : '-';
 }
 return p->cmdfirstc;
}

/// Get the current command line in allocated memory.
/// Only works when the command line is being edited.
///
/// @return  NULL when something is wrong.
static char *get_cmdline_str(void)
{
 if (cmdline_star > 0) {
   return NULL;
 }
 CmdlineInfo *p = get_ccline_ptr();

 if (p == NULL) {
   return NULL;
 }
 return xstrnsave(p->cmdbuff, (size_t)p->cmdlen);
}

/// Get the current command-line completion pattern.
static char *get_cmdline_completion_pattern(void)
{
 if (cmdline_star > 0) {
   return NULL;
 }

 CmdlineInfo *p = get_ccline_ptr();
 if (p == NULL || p->xpc == NULL) {
   return NULL;
 }

 int xp_context = p->xpc->xp_context;
 if (xp_context == EXPAND_NOTHING) {
   set_expand_context(p->xpc);
   xp_context = p->xpc->xp_context;
   p->xpc->xp_context = EXPAND_NOTHING;
 }
 if (xp_context == EXPAND_UNSUCCESSFUL) {
   return NULL;
 }

 char *compl_pat = p->xpc->xp_pattern;
 if (compl_pat == NULL) {
   return NULL;
 }

 return xstrdup(compl_pat);
}

/// Get the command-line completion type.
static char *get_cmdline_completion(void)
{
 if (cmdline_star > 0) {
   return NULL;
 }

 CmdlineInfo *p = get_ccline_ptr();
 if (p == NULL || p->xpc == NULL) {
   return NULL;
 }

 int xp_context = p->xpc->xp_context;
 if (xp_context == EXPAND_NOTHING) {
   set_expand_context(p->xpc);
   xp_context = p->xpc->xp_context;
   p->xpc->xp_context = EXPAND_NOTHING;
 }
 if (xp_context == EXPAND_UNSUCCESSFUL) {
   return NULL;
 }

 return cmdcomplete_type_to_str(xp_context, p->xpc->xp_arg);
}

/// "getcmdcomplpat()" function
void f_getcmdcomplpat(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 rettv->v_type = VAR_STRING;
 rettv->vval.v_string = get_cmdline_completion_pattern();
}

/// "getcmdcompltype()" function
void f_getcmdcompltype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 rettv->v_type = VAR_STRING;
 rettv->vval.v_string = get_cmdline_completion();
}

/// "getcmdline()" function
void f_getcmdline(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 rettv->v_type = VAR_STRING;
 rettv->vval.v_string = get_cmdline_str();
}

/// "getcmdpos()" function
void f_getcmdpos(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 CmdlineInfo *p = get_ccline_ptr();
 rettv->vval.v_number = p != NULL ? p->cmdpos + 1 : 0;
}

/// "getcmdprompt()" function
void f_getcmdprompt(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 CmdlineInfo *p = get_ccline_ptr();
 rettv->v_type = VAR_STRING;
 rettv->vval.v_string = p != NULL && p->cmdprompt != NULL
                        ? xstrdup(p->cmdprompt) : NULL;
}

/// "getcmdscreenpos()" function
void f_getcmdscreenpos(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 CmdlineInfo *p = get_ccline_ptr();
 rettv->vval.v_number = p != NULL ? p->cmdspos + 1 : 0;
}

/// "getcmdtype()" function
void f_getcmdtype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 rettv->v_type = VAR_STRING;
 rettv->vval.v_string = xmallocz(1);
 rettv->vval.v_string[0] = (char)get_cmdline_type();
}

/// Set the command line str to "str".
/// @return  1 when failed, 0 when OK.
static int set_cmdline_str(const char *str, int pos)
{
 CmdlineInfo *p = get_ccline_ptr();

 if (p == NULL) {
   return 1;
 }

 int len = (int)strlen(str);
 realloc_cmdbuff(len + 1);
 p->cmdlen = len;
 STRCPY(p->cmdbuff, str);

 p->cmdpos = pos < 0 || pos > p->cmdlen ? p->cmdlen : pos;
 new_cmdpos = p->cmdpos;

 redrawcmd();

 // Trigger CmdlineChanged autocommands.
 do_autocmd_cmdlinechanged(get_cmdline_type());

 return 0;
}

/// Set the command line byte position to "pos".  Zero is the first position.
/// Only works when the command line is being edited.
/// @return  1 when failed, 0 when OK.
static int set_cmdline_pos(int pos)
{
 CmdlineInfo *p = get_ccline_ptr();

 if (p == NULL) {
   return 1;
 }

 // The position is not set directly but after CTRL-\ e or CTRL-R = has
 // changed the command line.
 new_cmdpos = MAX(0, pos);

 return 0;
}

/// "setcmdline()" function
void f_setcmdline(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 if (tv_check_for_string_arg(argvars, 0) == FAIL
     || tv_check_for_opt_number_arg(argvars, 1) == FAIL) {
   return;
 }

 int pos = -1;
 if (argvars[1].v_type != VAR_UNKNOWN) {
   bool error = false;

   pos = (int)tv_get_number_chk(&argvars[1], &error) - 1;
   if (error) {
     return;
   }
   if (pos < 0) {
     emsg(_(e_positive));
     return;
   }
 }

 // Use tv_get_string() to handle a NULL string like an empty string.
 rettv->vval.v_number = set_cmdline_str(tv_get_string(&argvars[0]), pos);
}

/// "setcmdpos()" function
void f_setcmdpos(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 const int pos = (int)tv_get_number(&argvars[0]) - 1;

 if (pos >= 0) {
   rettv->vval.v_number = set_cmdline_pos(pos);
 }
}

/// Return the first character of the current command line.
int get_cmdline_firstc(void)
{
 return ccline.cmdfirstc;
}

/// Get indices that specify a range within a list (not a range of text lines
/// in a buffer!) from a string.  Used for ":history" and ":clist".
///
/// @param str string to parse range from
/// @param num1 from
/// @param num2 to
///
/// @return OK if parsed successfully, otherwise FAIL.
int get_list_range(char **str, int *num1, int *num2)
{
 int len;
 bool first = false;
 varnumber_T num;

 *str = skipwhite((*str));
 if (**str == '-' || ascii_isdigit(**str)) {  // parse "from" part of range
   vim_str2nr(*str, NULL, &len, 0, &num, NULL, 0, false, NULL);
   *str += len;
   // overflow
   if (num > INT_MAX) {
     return FAIL;
   }

   *num1 = (int)num;
   first = true;
 }
 *str = skipwhite((*str));
 if (**str == ',') {                   // parse "to" part of range
   *str = skipwhite((*str) + 1);
   vim_str2nr(*str, NULL, &len, 0, &num, NULL, 0, false, NULL);
   if (len > 0) {
     *str = skipwhite((*str) + len);
     // overflow
     if (num > INT_MAX) {
       return FAIL;
     }

     *num2 = (int)num;
   } else if (!first) {                  // no number given at all
     return FAIL;
   }
 } else if (first) {                     // only one number given
   *num2 = *num1;
 }
 return OK;
}

void cmdline_init(void)
{
 CLEAR_FIELD(ccline);
}

/// Check value of 'cedit' and set cedit_key.
/// Returns NULL if value is OK, error message otherwise.
const char *did_set_cedit(optset_T *args)
{
 if (*p_cedit == NUL) {
   cedit_key = -1;
 } else {
   int n = string_to_key(p_cedit);
   if (n == 0 || vim_isprintc(n)) {
     return e_invarg;
   }
   cedit_key = n;
 }
 return NULL;
}

/// Open a window on the current command line and history.  Allow editing in
/// the window.  Returns when the window is closed.
/// Returns:
///     CR       if the command is to be executed
///     Ctrl_C   if it is to be abandoned
///     K_IGNORE if editing continues
static int open_cmdwin(void)
{
 bufref_T old_curbuf;
 bufref_T bufref;
 win_T *old_curwin = curwin;
 int i;
 garray_T winsizes;
 int save_restart_edit = restart_edit;
 int save_State = State;
 bool save_exmode = exmode_active;
 bool save_cmdmsg_rl = cmdmsg_rl;

 // Can't do this when text or buffer is locked.
 // Can't do this recursively.  Can't do it when typing a password.
 if (text_or_buf_locked() || cmdwin_type != 0 || cmdline_star > 0) {
   beep_flush();
   return K_IGNORE;
 }

 set_bufref(&old_curbuf, curbuf);

 // Save current window sizes.
 win_size_save(&winsizes);

 // When using completion in Insert mode with <C-R>=<C-F> one can open the
 // command line window, but we don't want the popup menu then.
 pum_undisplay(true);

 // don't use a new tab page
 cmdmod.cmod_tab = 0;
 cmdmod.cmod_flags |= CMOD_NOSWAPFILE;

 // Create a window for the command-line buffer.
 if (win_split((int)p_cwh, WSP_BOT) == FAIL) {
   beep_flush();
   ga_clear(&winsizes);
   return K_IGNORE;
 }
 // win_split() autocommands may have messed with the old window or buffer.
 // Treat it as abandoning this command-line.
 if (!win_valid(old_curwin) || curwin == old_curwin || !bufref_valid(&old_curbuf)
     || old_curwin->w_buffer != old_curbuf.br_buf) {
   beep_flush();
   ga_clear(&winsizes);
   return Ctrl_C;
 }
 // Don't let quitting the More prompt make this fail.
 got_int = false;

 // Set "cmdwin_..." variables before any autocommands may mess things up.
 cmdwin_type = get_cmdline_type();
 cmdwin_level = ccline.level;
 cmdwin_win = curwin;
 cmdwin_old_curwin = old_curwin;

 // Create empty command-line buffer.  Be especially cautious of BufLeave
 // autocommands from do_ecmd(), as cmdwin restrictions do not apply to them!
 const int newbuf_status = buf_open_scratch(0, NULL);
 const bool cmdwin_valid = win_valid(cmdwin_win);
 if (newbuf_status == FAIL || !cmdwin_valid || curwin != cmdwin_win || !win_valid(old_curwin)
     || !bufref_valid(&old_curbuf) || old_curwin->w_buffer != old_curbuf.br_buf) {
   if (newbuf_status == OK) {
     set_bufref(&bufref, curbuf);
   }
   if (cmdwin_valid && !last_window(cmdwin_win)) {
     win_close(cmdwin_win, true, false);
   }
   // win_close() autocommands may have already deleted the buffer.
   if (newbuf_status == OK && bufref_valid(&bufref) && bufref.br_buf != curbuf) {
     close_buffer(NULL, bufref.br_buf, DOBUF_WIPE, false, false);
   }

   cmdwin_type = 0;
   cmdwin_level = 0;
   cmdwin_win = NULL;
   cmdwin_old_curwin = NULL;
   beep_flush();
   ga_clear(&winsizes);
   return Ctrl_C;
 }
 cmdwin_buf = curbuf;

 // Command-line buffer has bufhidden=wipe, unlike a true "scratch" buffer.
 set_option_value_give_err(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("wipe"), OPT_LOCAL);
 curbuf->b_p_ma = true;
 curwin->w_p_fen = false;
 curwin->w_p_rl = cmdmsg_rl;
 cmdmsg_rl = false;

 // Don't allow switching to another buffer.
 curbuf->b_ro_locked++;

 // Showing the prompt may have set need_wait_return, reset it.
 need_wait_return = false;

 const int histtype = hist_char2type(cmdwin_type);
 if (histtype == HIST_CMD || histtype == HIST_DEBUG) {
   if (p_wc == TAB) {
     add_map("<Tab>", "<C-X><C-V>", MODE_INSERT, true);
     add_map("<Tab>", "a<C-X><C-V>", MODE_NORMAL, true);
   }
   set_option_value_give_err(kOptFiletype, STATIC_CSTR_AS_OPTVAL("vim"), OPT_LOCAL);
 }
 curbuf->b_ro_locked--;

 // Reset 'textwidth' after setting 'filetype' (the Vim filetype plugin
 // sets 'textwidth' to 78).
 curbuf->b_p_tw = 0;

 // Fill the buffer with the history.
 init_history();
 if (get_hislen() > 0 && histtype != HIST_INVALID) {
   i = *get_hisidx(histtype);
   if (i >= 0) {
     linenr_T lnum = 0;
     do {
       if (++i == get_hislen()) {
         i = 0;
       }
       if (get_histentry(histtype)[i].hisstr != NULL) {
         ml_append(lnum++, get_histentry(histtype)[i].hisstr, 0, false);
       }
     } while (i != *get_hisidx(histtype));
   }
 }

 // Replace the empty last line with the current command-line and put the
 // cursor there.
 ml_replace(curbuf->b_ml.ml_line_count, ccline.cmdbuff, true);
 curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
 curwin->w_cursor.col = ccline.cmdpos;
 changed_line_abv_curs();
 invalidate_botline_win(curwin);
 ui_ext_cmdline_hide(false);
 redraw_later(curwin, UPD_SOME_VALID);

 // No Ex mode here!
 exmode_active = false;

 State = MODE_NORMAL;
 setmouse();
 clear_showcmd();

 // Reset here so it can be set by a CmdwinEnter autocommand.
 cmdwin_result = 0;

 // Trigger CmdwinEnter autocommands.
 trigger_cmd_autocmd(cmdwin_type, EVENT_CMDWINENTER);
 if (restart_edit != 0) {  // autocmd with ":startinsert"
   stuffcharReadbuff(K_NOP);
 }

 i = RedrawingDisabled;
 RedrawingDisabled = 0;
 int save_count = save_batch_count();

 // Call the main loop until <CR> or CTRL-C is typed.
 normal_enter(true, false);

 RedrawingDisabled = i;
 restore_batch_count(save_count);

 const bool save_KeyTyped = KeyTyped;

 // Trigger CmdwinLeave autocommands.
 trigger_cmd_autocmd(cmdwin_type, EVENT_CMDWINLEAVE);

 // Restore KeyTyped in case it is modified by autocommands
 KeyTyped = save_KeyTyped;

 cmdwin_type = 0;
 cmdwin_level = 0;
 cmdwin_buf = NULL;
 cmdwin_win = NULL;
 cmdwin_old_curwin = NULL;

 exmode_active = save_exmode;

 // Safety check: The old window or buffer was changed or deleted: It's a bug
 // when this happens!
 if (!win_valid(old_curwin) || !bufref_valid(&old_curbuf)
     || old_curwin->w_buffer != old_curbuf.br_buf) {
   cmdwin_result = Ctrl_C;
   emsg(_(e_active_window_or_buffer_changed_or_deleted));
 } else {
   win_T *wp;
   // autocmds may abort script processing
   if (aborting() && cmdwin_result != K_IGNORE) {
     cmdwin_result = Ctrl_C;
   }
   // Set the new command line from the cmdline buffer.
   dealloc_cmdbuff();

   if (cmdwin_result == K_XF1 || cmdwin_result == K_XF2) {  // :qa[!] typed
     const char *p = (cmdwin_result == K_XF2) ? "qa" : "qa!";
     size_t plen = (cmdwin_result == K_XF2) ? 2 : 3;

     if (histtype == HIST_CMD) {
       // Execute the command directly.
       ccline.cmdbuff = xmemdupz(p, plen);
       ccline.cmdlen = (int)plen;
       ccline.cmdbufflen = (int)plen + 1;
       cmdwin_result = CAR;
     } else {
       // First need to cancel what we were doing.
       stuffcharReadbuff(':');
       stuffReadbuff(p);
       stuffcharReadbuff(CAR);
     }
   } else if (cmdwin_result == Ctrl_C) {
     // :q or :close, don't execute any command
     // and don't modify the cmd window.
     ccline.cmdbuff = NULL;
   } else {
     ccline.cmdlen = get_cursor_line_len();
     ccline.cmdbufflen = ccline.cmdlen + 1;
     ccline.cmdbuff = xstrnsave(get_cursor_line_ptr(), (size_t)ccline.cmdlen);
   }

   if (ccline.cmdbuff == NULL) {
     ccline.cmdbuff = xmemdupz("", 0);
     ccline.cmdlen = 0;
     ccline.cmdbufflen = 1;
     ccline.cmdpos = 0;
     cmdwin_result = Ctrl_C;
   } else {
     ccline.cmdpos = curwin->w_cursor.col;
     // If the cursor is on the last character, it probably should be after it.
     if (ccline.cmdpos == ccline.cmdlen - 1 || ccline.cmdpos > ccline.cmdlen) {
       ccline.cmdpos = ccline.cmdlen;
     }
     if (cmdwin_result == K_IGNORE) {
       ccline.cmdspos = cmd_screencol(ccline.cmdpos);
       redrawcmd();
     }
   }

   // Avoid command-line window first character being concealed.
   curwin->w_p_cole = 0;
   // First go back to the original window.
   wp = curwin;
   set_bufref(&bufref, curbuf);
   skip_win_fix_cursor = true;
   win_goto(old_curwin);

   // win_goto() may trigger an autocommand that already closes the
   // cmdline window.
   if (win_valid(wp) && wp != curwin) {
     win_close(wp, true, false);
   }

   // win_close() may have already wiped the buffer when 'bh' is
   // set to 'wipe', autocommands may have closed other windows
   if (bufref_valid(&bufref) && bufref.br_buf != curbuf) {
     close_buffer(NULL, bufref.br_buf, DOBUF_WIPE, false, false);
   }

   // Restore window sizes.
   win_size_restore(&winsizes);
   skip_win_fix_cursor = false;
 }

 ga_clear(&winsizes);
 restart_edit = save_restart_edit;
 cmdmsg_rl = save_cmdmsg_rl;

 State = save_State;
 may_trigger_modechanged();
 setmouse();
 setcursor();

 return cmdwin_result;
}

/// @return true if in the cmdwin, not editing the command line.
bool is_in_cmdwin(void)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return cmdwin_type != 0 && get_cmdline_type() == NUL;
}

/// Get script string
///
/// Used for commands which accept either `:command script` or
///
///     :command << endmarker
///       script
///     endmarker
///
/// @param  eap  Command being run.
/// @param[out]  lenp  Location where length of resulting string is saved. Will
///                    be set to zero when skipping.
///
/// @return [allocated] NULL or script. Does not show any error messages.
///                     NULL is returned when skipping and on error.
char *script_get(exarg_T *const eap, size_t *const lenp)
 FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_MALLOC
{
 char *cmd = eap->arg;

 if (cmd[0] != '<' || cmd[1] != '<' || eap->ea_getline == NULL) {
   *lenp = strlen(eap->arg);
   return eap->skip ? NULL : xmemdupz(eap->arg, *lenp);
 }
 cmd += 2;

 garray_T ga = { .ga_data = NULL, .ga_len = 0 };

 list_T *const l = heredoc_get(eap, cmd, true);
 if (l == NULL) {
   return NULL;
 }

 if (!eap->skip) {
   ga_init(&ga, 1, 0x400);
 }

 TV_LIST_ITER_CONST(l, li, {
   if (!eap->skip) {
     ga_concat(&ga, tv_get_string(TV_LIST_ITEM_TV(li)));
     ga_append(&ga, '\n');
   }
 });
 *lenp = (size_t)ga.ga_len;  // Set length without trailing NUL.
 if (!eap->skip) {
   ga_append(&ga, NUL);
 }

 tv_list_free(l);
 return (char *)ga.ga_data;
}

/// This function is used by f_input() and f_inputdialog() functions. The third
/// argument to f_input() specifies the type of completion to use at the
/// prompt. The third argument to f_inputdialog() specifies the value to return
/// when the user cancels the prompt.
void get_user_input(const typval_T *const argvars, typval_T *const rettv, const bool inputdialog,
                   const bool secret)
 FUNC_ATTR_NONNULL_ALL
{
 rettv->v_type = VAR_STRING;
 rettv->vval.v_string = NULL;

 if (cmdpreview) {
   return;
 }

 const char *prompt;
 const char *defstr = "";
 typval_T *cancelreturn = NULL;
 typval_T cancelreturn_strarg2 = TV_INITIAL_VALUE;
 const char *xp_name = NULL;
 Callback input_callback = CALLBACK_INIT;
 char prompt_buf[NUMBUFLEN];
 char defstr_buf[NUMBUFLEN];
 char cancelreturn_buf[NUMBUFLEN];
 char xp_name_buf[NUMBUFLEN];
 char def[1] = { 0 };
 if (argvars[0].v_type == VAR_DICT) {
   if (argvars[1].v_type != VAR_UNKNOWN) {
     emsg(_("E5050: {opts} must be the only argument"));
     return;
   }
   dict_T *const dict = argvars[0].vval.v_dict;
   prompt = tv_dict_get_string_buf_chk(dict, S_LEN("prompt"), prompt_buf, "");
   if (prompt == NULL) {
     return;
   }
   defstr = tv_dict_get_string_buf_chk(dict, S_LEN("default"), defstr_buf, "");
   if (defstr == NULL) {
     return;
   }
   dictitem_T *cancelreturn_di = tv_dict_find(dict, S_LEN("cancelreturn"));
   if (cancelreturn_di != NULL) {
     cancelreturn = &cancelreturn_di->di_tv;
   }
   xp_name = tv_dict_get_string_buf_chk(dict, S_LEN("completion"),
                                        xp_name_buf, def);
   if (xp_name == NULL) {  // error
     return;
   }
   if (xp_name == def) {  // default to NULL
     xp_name = NULL;
   }
   if (!tv_dict_get_callback(dict, S_LEN("highlight"), &input_callback)) {
     return;
   }
 } else {
   prompt = tv_get_string_buf_chk(&argvars[0], prompt_buf);
   if (prompt == NULL) {
     return;
   }
   if (argvars[1].v_type != VAR_UNKNOWN) {
     defstr = tv_get_string_buf_chk(&argvars[1], defstr_buf);
     if (defstr == NULL) {
       return;
     }
     if (argvars[2].v_type != VAR_UNKNOWN) {
       const char *const strarg2 = tv_get_string_buf_chk(&argvars[2], cancelreturn_buf);
       if (strarg2 == NULL) {
         return;
       }
       if (inputdialog) {
         cancelreturn_strarg2.v_type = VAR_STRING;
         cancelreturn_strarg2.vval.v_string = (char *)strarg2;
         cancelreturn = &cancelreturn_strarg2;
       } else {
         xp_name = strarg2;
       }
     }
   }
 }

 int xp_type = EXPAND_NOTHING;
 char *xp_arg = NULL;
 if (xp_name != NULL) {
   // input() with a third argument: completion
   const int xp_namelen = (int)strlen(xp_name);

   uint32_t argt = 0;
   if (parse_compl_arg(xp_name, xp_namelen, &xp_type,
                       &argt, &xp_arg) == FAIL) {
     return;
   }
 }

 // Only the part of the message after the last NL is considered as
 // prompt for the command line, unlsess cmdline is externalized
 const char *p = prompt;
 if (!ui_has(kUICmdline)) {
   const char *lastnl = strrchr(prompt, '\n');
   if (lastnl != NULL) {
     p = lastnl + 1;
     msg_start();
     msg_clr_eos();
     msg_puts_len(prompt, p - prompt, get_echo_hl_id(), false);
     msg_didout = false;
     msg_starthere();
   }
 }
 cmdline_row = msg_row;

 stuffReadbuffSpec(defstr);

 const int save_ex_normal_busy = ex_normal_busy;
 ex_normal_busy = 0;
 rettv->vval.v_string = getcmdline_prompt(secret ? NUL : '@', p, get_echo_hl_id(),
                                          xp_type, xp_arg, input_callback, false, NULL);
 ex_normal_busy = save_ex_normal_busy;
 callback_free(&input_callback);

 if (rettv->vval.v_string == NULL && cancelreturn != NULL) {
   tv_copy(cancelreturn, rettv);
 }

 xfree(xp_arg);

 // Since the user typed this, no need to wait for return.
 need_wait_return = false;
 msg_didout = false;
}

/// "wildtrigger()" function
void f_wildtrigger(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
{
 if (!(State & MODE_CMDLINE) || char_avail()
     || wild_menu_showing
     || cmdline_pum_active()) {
   return;
 }

 int cmd_type = get_cmdline_type();

 if (cmd_type == ':' || cmd_type == '/' || cmd_type == '?') {
   // Add K_WILD as a single special key
   uint8_t key_string[4];
   key_string[0] = K_SPECIAL;
   key_string[1] = KS_EXTRA;
   key_string[2] = KE_WILD;
   key_string[3] = NUL;

   // Insert it into the typeahead buffer
   ins_typebuf((char *)key_string, REMAP_NONE, 0, true, false);
 }
}