neovim

buffer.c (135454B)

---

//
// buffer.c: functions for dealing with the buffer structure
//

//
// The buffer list is a double linked list of all buffers.
// Each buffer can be in one of these states:
// never loaded: BF_NEVERLOADED is set, only the file name is valid
//   not loaded: b_ml.ml_mfp == NULL, no memfile allocated
//       hidden: b_nwindows == 0, loaded but not displayed in a window
//       normal: loaded and displayed in a window
//
// Instead of storing file names all over the place, each file name is
// stored in the buffer list. It can be referenced by a number.
//
// The current implementation remembers all file names ever used.
//

#include <assert.h>
#include <ctype.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>

#include "auto/config.h"
#include "klib/kvec.h"
#include "nvim/api/private/helpers.h"
#include "nvim/arglist.h"
#include "nvim/ascii_defs.h"
#include "nvim/assert_defs.h"
#include "nvim/autocmd.h"
#include "nvim/autocmd_defs.h"
#include "nvim/buffer.h"
#include "nvim/buffer_updates.h"
#include "nvim/change.h"
#include "nvim/channel.h"
#include "nvim/charset.h"
#include "nvim/cmdexpand.h"
#include "nvim/cursor.h"
#include "nvim/diff.h"
#include "nvim/digraph.h"
#include "nvim/drawscreen.h"
#include "nvim/errors.h"
#include "nvim/eval/typval.h"
#include "nvim/eval/vars.h"
#include "nvim/ex_cmds.h"
#include "nvim/ex_cmds2.h"
#include "nvim/ex_cmds_defs.h"
#include "nvim/ex_docmd.h"
#include "nvim/ex_eval.h"
#include "nvim/ex_eval_defs.h"
#include "nvim/ex_getln.h"
#include "nvim/extmark.h"
#include "nvim/file_search.h"
#include "nvim/fileio.h"
#include "nvim/fold.h"
#include "nvim/fuzzy.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/hashtab.h"
#include "nvim/hashtab_defs.h"
#include "nvim/help.h"
#include "nvim/indent.h"
#include "nvim/indent_c.h"
#include "nvim/insexpand.h"
#include "nvim/main.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/memfile_defs.h"
#include "nvim/memline.h"
#include "nvim/memline_defs.h"
#include "nvim/memory.h"
#include "nvim/message.h"
#include "nvim/move.h"
#include "nvim/normal.h"
#include "nvim/option.h"
#include "nvim/option_defs.h"
#include "nvim/option_vars.h"
#include "nvim/optionstr.h"
#include "nvim/os/fs.h"
#include "nvim/os/fs_defs.h"
#include "nvim/os/input.h"
#include "nvim/os/os.h"
#include "nvim/os/os_defs.h"
#include "nvim/os/time.h"
#include "nvim/path.h"
#include "nvim/plines.h"
#include "nvim/pos_defs.h"
#include "nvim/quickfix.h"
#include "nvim/regexp.h"
#include "nvim/regexp_defs.h"
#include "nvim/runtime.h"
#include "nvim/runtime_defs.h"
#include "nvim/spell.h"
#include "nvim/state_defs.h"
#include "nvim/statusline.h"
#include "nvim/strings.h"
#include "nvim/syntax.h"
#include "nvim/terminal.h"
#include "nvim/ui.h"
#include "nvim/undo.h"
#include "nvim/usercmd.h"
#include "nvim/version.h"
#include "nvim/vim_defs.h"
#include "nvim/window.h"
#include "nvim/winfloat.h"

#include "buffer.c.generated.h"

#ifdef ABORT_ON_INTERNAL_ERROR
# define CHECK_CURBUF \
 do { \
   if (curwin != NULL && curwin->w_buffer != curbuf) { \
     iemsg("curbuf != curwin->w_buffer"); \
   } \
 } while (0)
#else
# define CHECK_CURBUF do {} while (0)
#endif

static const char e_attempt_to_delete_buffer_that_is_in_use_str[]
 = N_("E937: Attempt to delete a buffer that is in use: %s");

// Number of times free_buffer() was called.
static int buf_free_count = 0;

static int top_file_num = 1;            ///< highest file number

typedef enum {
 kBffClearWinInfo = 1,
 kBffInitChangedtick = 2,
} BufFreeFlags;

static void trigger_undo_ftplugin(buf_T *buf, win_T *win)
{
 const bool win_was_locked = win->w_locked;
 window_layout_lock();
 buf->b_locked++;
 win->w_locked = true;
 // b:undo_ftplugin may be set, undo it
 do_cmdline_cmd("if exists('b:undo_ftplugin') | exe b:undo_ftplugin | endif");
 buf->b_locked--;
 win->w_locked = win_was_locked;
 window_layout_unlock();
}

/// Calculate the percentage that `part` is of the `whole`.
int calc_percentage(int64_t part, int64_t whole)
{
 // With 32 bit longs and more than 21,474,836 lines multiplying by 100
 // causes an overflow, thus for large numbers divide instead.
 return (part > 1000000) ? (int)(part / (whole / 100))
                         : (int)((part * 100) / whole);
}

/// @return  the highest possible buffer number
int get_highest_fnum(void)
{
 return top_file_num - 1;
}

/// Read data from buffer for retrying.
///
/// @param read_stdin  read file from stdin, otherwise fifo
/// @param eap  for forced 'ff' and 'fenc' or NULL
/// @param flags  extra flags for readfile()
static int read_buffer(bool read_stdin, exarg_T *eap, int flags)
{
 int retval = OK;
 bool silent = shortmess(SHM_FILEINFO);

 // Read from the buffer which the text is already filled in and append at
 // the end.  This makes it possible to retry when 'fileformat' or
 // 'fileencoding' was guessed wrong.
 linenr_T line_count = curbuf->b_ml.ml_line_count;
 retval = readfile(read_stdin ? NULL : curbuf->b_ffname,
                   read_stdin ? NULL : curbuf->b_fname,
                   line_count, 0, (linenr_T)MAXLNUM, eap,
                   flags | READ_BUFFER, silent);
 if (retval == OK) {
   // Delete the binary lines.
   while (--line_count >= 0) {
     ml_delete(1);
   }
 } else {
   // Delete the converted lines.
   while (curbuf->b_ml.ml_line_count > line_count) {
     ml_delete(line_count);
   }
 }
 // Put the cursor on the first line.
 curwin->w_cursor.lnum = 1;
 curwin->w_cursor.col = 0;

 if (read_stdin) {
   // Set or reset 'modified' before executing autocommands, so that
   // it can be changed there.
   if (!readonlymode && !buf_is_empty(curbuf)) {
     changed(curbuf);
   } else if (retval != FAIL) {
     unchanged(curbuf, false, true);
   }

   apply_autocmds_retval(EVENT_STDINREADPOST, NULL, NULL, false,
                         curbuf, &retval);
 }
 return retval;
}

/// Ensure buffer "buf" is loaded.
bool buf_ensure_loaded(buf_T *buf)
{
 if (buf->b_ml.ml_mfp != NULL) {
   // already open (common case)
   return true;
 }

 aco_save_T aco;

 // Make sure the buffer is in a window.
 aucmd_prepbuf(&aco, buf);
 // status can be OK or NOTDONE (which also means ok/done)
 int status = open_buffer(false, NULL, 0);
 aucmd_restbuf(&aco);
 return (status != FAIL);
}

/// Open current buffer, that is: open the memfile and read the file into
/// memory.
///
/// @param read_stdin  read file from stdin
/// @param eap  for forced 'ff' and 'fenc' or NULL
/// @param flags_arg  extra flags for readfile()
///
/// @return  FAIL for failure, OK otherwise.
int open_buffer(bool read_stdin, exarg_T *eap, int flags_arg)
{
 int flags = flags_arg;
 int retval = OK;
 bufref_T old_curbuf;
 OptInt old_tw = curbuf->b_p_tw;
 bool read_fifo = false;
 bool silent = shortmess(SHM_FILEINFO);

 // The 'readonly' flag is only set when BF_NEVERLOADED is being reset.
 // When re-entering the same buffer, it should not change, because the
 // user may have reset the flag by hand.
 if (readonlymode && curbuf->b_ffname != NULL
     && (curbuf->b_flags & BF_NEVERLOADED)) {
   curbuf->b_p_ro = true;
 }

 if (ml_open(curbuf) == FAIL) {
   // There MUST be a memfile, otherwise we can't do anything
   // If we can't create one for the current buffer, take another buffer
   close_buffer(NULL, curbuf, 0, false, false);

   curbuf = NULL;
   FOR_ALL_BUFFERS(buf) {
     if (buf->b_ml.ml_mfp != NULL) {
       curbuf = buf;
       break;
     }
   }

   // If there is no memfile at all, exit.
   // This is OK, since there are no changes to lose.
   if (curbuf == NULL) {
     emsg(_("E82: Cannot allocate any buffer, exiting..."));

     // Don't try to do any saving, with "curbuf" NULL almost nothing
     // will work.
     v_dying = 2;
     getout(2);
   }

   emsg(_("E83: Cannot allocate buffer, using other one..."));
   enter_buffer(curbuf);
   if (old_tw != curbuf->b_p_tw) {
     check_colorcolumn(NULL, curwin);
   }
   return FAIL;
 }

 // Do not sync this buffer yet, may first want to read the file.
 if (curbuf->b_ml.ml_mfp != NULL) {
   curbuf->b_ml.ml_mfp->mf_dirty = MF_DIRTY_YES_NOSYNC;
 }

 // The autocommands in readfile() may change the buffer, but only AFTER
 // reading the file.
 set_bufref(&old_curbuf, curbuf);
 curbuf->b_modified_was_set = false;

 // mark cursor position as being invalid
 curwin->w_valid = 0;

 // A buffer without an actual file should not use the buffer name to read a
 // file.
 if (bt_nofileread(curbuf)) {
   flags |= READ_NOFILE;
 }

 // Read the file if there is one.
 if (curbuf->b_ffname != NULL) {
#ifdef UNIX
   int save_bin = curbuf->b_p_bin;
   int perm = os_getperm(curbuf->b_ffname);
   if (perm >= 0 && (0 || S_ISFIFO(perm)
                     || S_ISSOCK(perm)
# ifdef OPEN_CHR_FILES
                     || (S_ISCHR(perm)
                         && is_dev_fd_file(curbuf->b_ffname))
# endif
                     )) {
     read_fifo = true;
   }
   if (read_fifo) {
     curbuf->b_p_bin = true;
   }
#endif

   retval = readfile(curbuf->b_ffname, curbuf->b_fname,
                     0, 0, (linenr_T)MAXLNUM, eap,
                     flags | READ_NEW | (read_fifo ? READ_FIFO : 0), silent);
#ifdef UNIX
   if (read_fifo) {
     curbuf->b_p_bin = save_bin;
     if (retval == OK) {
       // don't add READ_FIFO here, otherwise we won't be able to
       // detect the encoding
       retval = read_buffer(false, eap, flags);
     }
   }
#endif

   // Help buffer: populate *local-additions* in help.txt
   if (bt_help(curbuf)) {
     get_local_additions();
   }
 } else if (read_stdin) {
   int save_bin = curbuf->b_p_bin;

   // First read the text in binary mode into the buffer.
   // Then read from that same buffer and append at the end.  This makes
   // it possible to retry when 'fileformat' or 'fileencoding' was
   // guessed wrong.
   curbuf->b_p_bin = true;
   retval = readfile(NULL, NULL, 0,
                     0, (linenr_T)MAXLNUM, NULL,
                     flags | (READ_NEW + READ_STDIN), silent);
   curbuf->b_p_bin = save_bin;
   if (retval == OK) {
     retval = read_buffer(true, eap, flags);
   }
 }

 // Can now sync this buffer in ml_sync_all().
 if (curbuf->b_ml.ml_mfp != NULL
     && curbuf->b_ml.ml_mfp->mf_dirty == MF_DIRTY_YES_NOSYNC) {
   curbuf->b_ml.ml_mfp->mf_dirty = MF_DIRTY_YES;
 }

 // if first time loading this buffer, init b_chartab[]
 if (curbuf->b_flags & BF_NEVERLOADED) {
   buf_init_chartab(curbuf, false);
   parse_cino(curbuf);
 }

 // Set/reset the Changed flag first, autocmds may change the buffer.
 // Apply the automatic commands, before processing the modelines.
 // So the modelines have priority over autocommands.

 // When reading stdin, the buffer contents always needs writing, so set
 // the changed flag.  Unless in readonly mode: "ls | nvim -R -".
 // When interrupted and 'cpoptions' contains 'i' set changed flag.
 if ((got_int && vim_strchr(p_cpo, CPO_INTMOD) != NULL)
     || curbuf->b_modified_was_set  // autocmd did ":set modified"
     || (aborting() && vim_strchr(p_cpo, CPO_INTMOD) != NULL)) {
   changed(curbuf);
 } else if (retval != FAIL && !read_stdin && !read_fifo) {
   unchanged(curbuf, false, true);
 }
 save_file_ff(curbuf);                 // keep this fileformat

 // Set last_changedtick to avoid triggering a TextChanged autocommand right
 // after it was added.
 curbuf->b_last_changedtick = buf_get_changedtick(curbuf);
 curbuf->b_last_changedtick_i = buf_get_changedtick(curbuf);
 curbuf->b_last_changedtick_pum = buf_get_changedtick(curbuf);

 // require "!" to overwrite the file, because it wasn't read completely
 if (aborting()) {
   curbuf->b_flags |= BF_READERR;
 }

 // Need to update automatic folding.  Do this before the autocommands,
 // they may use the fold info.
 foldUpdateAll(curwin);

 // need to set w_topline, unless some autocommand already did that.
 if (!(curwin->w_valid & VALID_TOPLINE)) {
   curwin->w_topline = 1;
   curwin->w_topfill = 0;
 }
 apply_autocmds_retval(EVENT_BUFENTER, NULL, NULL, false, curbuf, &retval);

 // if (retval != OK) {
 if (retval == FAIL) {
   return retval;
 }

 // The autocommands may have changed the current buffer.  Apply the
 // modelines to the correct buffer, if it still exists and is loaded.
 if (bufref_valid(&old_curbuf) && old_curbuf.br_buf->b_ml.ml_mfp != NULL) {
   aco_save_T aco;

   // Go to the buffer that was opened, make sure it is in a window.
   aucmd_prepbuf(&aco, old_curbuf.br_buf);
   do_modelines(0);
   curbuf->b_flags &= ~(BF_CHECK_RO | BF_NEVERLOADED);

   if ((flags & READ_NOWINENTER) == 0) {
     apply_autocmds_retval(EVENT_BUFWINENTER, NULL, NULL, false, curbuf,
                           &retval);
   }

   // restore curwin/curbuf and a few other things
   aucmd_restbuf(&aco);
 }

 return retval;
}

/// Store "buf" in "bufref" and set the free count.
///
/// @param bufref Reference to be used for the buffer.
/// @param buf    The buffer to reference.
void set_bufref(bufref_T *bufref, buf_T *buf)
{
 bufref->br_buf = buf;
 bufref->br_fnum = buf == NULL ? 0 : buf->b_fnum;
 bufref->br_buf_free_count = buf_free_count;
}

/// Return true if "bufref->br_buf" points to the same buffer as when
/// set_bufref() was called and it is a valid buffer.
/// Only goes through the buffer list if buf_free_count changed.
/// Also checks if b_fnum is still the same, a :bwipe followed by :new might get
/// the same allocated memory, but it's a different buffer.
///
/// @param bufref Buffer reference to check for.
bool bufref_valid(bufref_T *bufref)
 FUNC_ATTR_PURE
{
 return bufref->br_buf_free_count == buf_free_count
        ? true
        : buf_valid(bufref->br_buf) && bufref->br_fnum == bufref->br_buf->b_fnum;
}

/// Check that "buf" points to a valid buffer in the buffer list.
///
/// Can be slow if there are many buffers, prefer using bufref_valid().
///
/// @param buf The buffer to check for.
bool buf_valid(buf_T *buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 if (buf == NULL) {
   return false;
 }
 // Assume that we more often have a recent buffer,
 // start with the last one.
 for (buf_T *bp = lastbuf; bp != NULL; bp = bp->b_prev) {
   if (bp == buf) {
     return true;
   }
 }
 return false;
}

/// Return true when buffer "buf" can be unloaded.
/// Give an error message and return false when the buffer is locked or the
/// screen is being redrawn and the buffer is in a window.
static bool can_unload_buffer(buf_T *buf)
{
 bool can_unload = !buf->b_locked;

 if (can_unload && updating_screen) {
   FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
     if (wp->w_buffer == buf) {
       can_unload = false;
       break;
     }
   }
 }
 // Don't unload the buffer while it's still being saved
 if (can_unload && buf->b_saving) {
   can_unload = false;
 }

 if (!can_unload) {
   char *fname = buf->b_fname != NULL ? buf->b_fname : buf->b_ffname;
   semsg(_(e_attempt_to_delete_buffer_that_is_in_use_str),
         fname != NULL ? fname : "[No Name]");
 }
 return can_unload;
}

void buf_close_terminal(buf_T *buf)
{
 assert(buf->terminal);
 buf->b_locked++;
 terminal_close(&buf->terminal, -1);
 buf->b_locked--;
}

/// Close the link to a buffer.
///
/// @param win    If not NULL, set b_last_cursor.
/// @param buf
/// @param action Used when there is no longer a window for the buffer.
///               Possible values:
///                 0            buffer becomes hidden
///                 DOBUF_UNLOAD buffer is unloaded
///                 DOBUF_DEL    buffer is unloaded and removed from buffer list
///                 DOBUF_WIPE   buffer is unloaded and really deleted
///               When doing all but the first one on the current buffer, the
///               caller should get a new buffer very soon!
///               The 'bufhidden' option can force freeing and deleting.
/// @param abort_if_last
///               If true, do not close the buffer if autocommands cause
///               there to be only one window with this buffer. e.g. when
///               ":quit" is supposed to close the window but autocommands
///               close all other windows.
/// @param ignore_abort
///               If true, don't abort even when aborting() returns true.
/// @return  true if b_nwindows was decremented directly by this call (e.g: not via autocmds).
bool close_buffer(win_T *win, buf_T *buf, int action, bool abort_if_last, bool ignore_abort)
{
 bool unload_buf = (action != 0);
 bool del_buf = (action == DOBUF_DEL || action == DOBUF_WIPE);
 bool wipe_buf = (action == DOBUF_WIPE);

 bool is_curwin = (curwin != NULL && curwin->w_buffer == buf);
 win_T *the_curwin = curwin;
 tabpage_T *the_curtab = curtab;

 CHECK_CURBUF;

 // Force unloading or deleting when 'bufhidden' says so, but not for terminal
 // buffers.
 // The caller must take care of NOT deleting/freeing when 'bufhidden' is
 // "hide" (otherwise we could never free or delete a buffer).
 if (!buf->terminal) {
   if (buf->b_p_bh[0] == 'd') {         // 'bufhidden' == "delete"
     del_buf = true;
     unload_buf = true;
   } else if (buf->b_p_bh[0] == 'w') {  // 'bufhidden' == "wipe"
     del_buf = true;
     unload_buf = true;
     wipe_buf = true;
   } else if (buf->b_p_bh[0] == 'u') {  // 'bufhidden' == "unload"
     unload_buf = true;
   }
 }

 if (buf->terminal && (unload_buf || del_buf || wipe_buf)) {
   // terminal buffers can only be wiped
   unload_buf = true;
   del_buf = true;
   wipe_buf = true;
 }

 // Disallow deleting the buffer when it is locked (already being closed or
 // halfway a command that relies on it). Unloading is allowed.
 if ((del_buf || wipe_buf) && !can_unload_buffer(buf)) {
   return false;
 }

 // check no autocommands closed the window
 if (win != NULL  // Avoid bogus clang warning.
     && win_valid_any_tab(win)) {
   // Set b_last_cursor when closing the last window for the buffer.
   // Remember the last cursor position and window options of the buffer.
   // This used to be only for the current window, but then options like
   // 'foldmethod' may be lost with a ":only" command.
   if (buf->b_nwindows == 1) {
     set_last_cursor(win);
   }
   buflist_setfpos(buf, win,
                   win->w_cursor.lnum == 1 ? 0 : win->w_cursor.lnum,
                   win->w_cursor.col, win->w_config.style != kWinStyleMinimal);
 }

 bufref_T bufref;
 set_bufref(&bufref, buf);

 // When the buffer is no longer in a window, trigger BufWinLeave
 if (buf->b_nwindows == 1) {
   buf->b_locked++;
   buf->b_locked_split++;
   if (apply_autocmds(EVENT_BUFWINLEAVE, buf->b_fname, buf->b_fname, false,
                      buf) && !bufref_valid(&bufref)) {
     // Autocommands deleted the buffer.
     emsg(_(e_auabort));
     return false;
   }
   buf->b_locked--;
   buf->b_locked_split--;
   if (abort_if_last && win != NULL && one_window(win, NULL)) {
     // Autocommands made this the only window.
     emsg(_(e_auabort));
     return false;
   }

   // When the buffer becomes hidden, but is not unloaded, trigger
   // BufHidden
   if (!unload_buf) {
     buf->b_locked++;
     buf->b_locked_split++;
     if (apply_autocmds(EVENT_BUFHIDDEN, buf->b_fname, buf->b_fname, false,
                        buf) && !bufref_valid(&bufref)) {
       // Autocommands deleted the buffer.
       emsg(_(e_auabort));
       return false;
     }
     buf->b_locked--;
     buf->b_locked_split--;
     if (abort_if_last && win != NULL && one_window(win, NULL)) {
       // Autocommands made this the only window.
       emsg(_(e_auabort));
       return false;
     }
   }
   // autocmds may abort script processing
   if (!ignore_abort && aborting()) {
     return false;
   }
 }

 // If the buffer was in curwin and the window has changed, go back to that
 // window, if it still exists.  This avoids that ":edit x" triggering a
 // "tabnext" BufUnload autocmd leaves a window behind without a buffer.
 if (is_curwin && curwin != the_curwin && win_valid_any_tab(the_curwin)) {
   block_autocmds();
   goto_tabpage_win(the_curtab, the_curwin);
   unblock_autocmds();
 }

 int nwindows = buf->b_nwindows;

 // decrease the link count from windows (unless not in any window)
 if (buf->b_nwindows > 0) {
   buf->b_nwindows--;
 }

 if (diffopt_hiddenoff() && !unload_buf && buf->b_nwindows == 0) {
   diff_buf_delete(buf);   // Clear 'diff' for hidden buffer.
 }

 // Return when a window is displaying the buffer or when it's not
 // unloaded.
 if (buf->b_nwindows > 0 || !unload_buf) {
   return true;
 }

 // Always remove the buffer when there is no file name.
 if (buf->b_ffname == NULL) {
   del_buf = true;
 }

 // Free all things allocated for this buffer.
 // Also calls the "BufDelete" autocommands when del_buf is true.
 // Remember if we are closing the current buffer.  Restore the number of
 // windows, so that autocommands in buf_freeall() don't get confused.
 bool is_curbuf = (buf == curbuf);

 // When closing the current buffer stop Visual mode before freeing
 // anything.
 if (is_curbuf && VIsual_active
#if defined(EXITFREE)
     && !entered_free_all_mem
#endif
     ) {
   end_visual_mode();
 }

 buf->b_nwindows = nwindows;

 buf_freeall(buf, ((del_buf ? BFA_DEL : 0)
                   + (wipe_buf ? BFA_WIPE : 0)
                   + (ignore_abort ? BFA_IGNORE_ABORT : 0)));

 if (!bufref_valid(&bufref)) {
   // Autocommands may have deleted the buffer.
   return false;
 }
 // autocmds may abort script processing.
 if (!ignore_abort && aborting()) {
   return false;
 }

 // It's possible that autocommands change curbuf to the one being deleted.
 // This might cause the previous curbuf to be deleted unexpectedly.  But
 // in some cases it's OK to delete the curbuf, because a new one is
 // obtained anyway.  Therefore only return if curbuf changed to the
 // deleted buffer.
 if (buf == curbuf && !is_curbuf) {
   return false;
 }

 bool clear_w_buf = false;
 if (win != NULL  // Avoid bogus clang warning.
     && win_valid_any_tab(win)
     && win->w_buffer == buf) {
   // Defer clearing w_buffer until after operations that may invoke dict
   // watchers (e.g., buf_clear_file()), so callers like tabpagebuflist()
   // never see a window in the winlist with a NULL buffer.
   clear_w_buf = true;
 }

 // Autocommands may have opened or closed windows for this buffer.
 // Decrement the count for the close we do here.
 // Don't decrement b_nwindows if the buffer wasn't displayed in any window
 // before calling buf_freeall().
 if (nwindows > 0 && buf->b_nwindows > 0) {
   buf->b_nwindows--;
 }

 // Remove the buffer from the list.
 // Do not wipe out the buffer if it is used in a window, or if autocommands
 // wiped out all other buffers (unless when inside free_all_mem() where all
 // buffers need to be freed and autocommands are blocked).
 if (wipe_buf && buf->b_nwindows <= 0 && (buf->b_prev != NULL || buf->b_next != NULL
#if defined(EXITFREE)
                                          || entered_free_all_mem
#endif
                                          )) {
   if (clear_w_buf) {
     win->w_buffer = NULL;
   }
   FOR_ALL_TAB_WINDOWS(tp, wp) {
     mark_forget_file(wp, buf->b_fnum);
   }
   if (buf->b_sfname != buf->b_ffname) {
     XFREE_CLEAR(buf->b_sfname);
   } else {
     buf->b_sfname = NULL;
   }
   XFREE_CLEAR(buf->b_ffname);
   if (buf->b_prev == NULL) {
     firstbuf = buf->b_next;
   } else {
     buf->b_prev->b_next = buf->b_next;
   }
   if (buf->b_next == NULL) {
     lastbuf = buf->b_prev;
   } else {
     buf->b_next->b_prev = buf->b_prev;
   }
   free_buffer(buf);
 } else {
   if (del_buf) {
     // Free all internal variables and reset option values, to make
     // ":bdel" compatible with Vim 5.7.
     free_buffer_stuff(buf, kBffClearWinInfo | kBffInitChangedtick);

     // Make it look like a new buffer.
     buf->b_flags = BF_CHECK_RO | BF_NEVERLOADED;

     // Init the options when loaded again.
     buf->b_p_initialized = false;
   }
   buf_clear_file(buf);
   if (clear_w_buf) {
     win->w_buffer = NULL;
   }
   if (del_buf) {
     buf->b_p_bl = false;
   }
 }
 // NOTE: at this point "curbuf" may be invalid!
 return true;
}

/// Make buffer not contain a file.
void buf_clear_file(buf_T *buf)
{
 buf->b_ml.ml_line_count = 1;
 unchanged(buf, true, true);
 buf->b_p_eof = false;
 buf->b_start_eof = false;
 buf->b_p_eol = true;
 buf->b_start_eol = true;
 buf->b_p_bomb = false;
 buf->b_start_bomb = false;
 buf->b_ml.ml_mfp = NULL;
 buf->b_ml.ml_flags = ML_EMPTY;                // empty buffer
}

/// Clears the current buffer contents.
void buf_clear(void)
{
 linenr_T line_count = curbuf->b_ml.ml_line_count;
 extmark_free_all(curbuf);   // delete any extmarks
 while (!(curbuf->b_ml.ml_flags & ML_EMPTY)) {
   ml_delete(1);
 }
 deleted_lines_mark(1, line_count);  // prepare for display
}

/// buf_freeall() - free all things allocated for a buffer that are related to
/// the file.  Careful: get here with "curwin" NULL when exiting.
///
/// @param flags BFA_DEL           buffer is going to be deleted
///              BFA_WIPE          buffer is going to be wiped out
///              BFA_KEEP_UNDO     do not free undo information
///              BFA_IGNORE_ABORT  don't abort even when aborting() returns true
void buf_freeall(buf_T *buf, int flags)
{
 bool is_curbuf = (buf == curbuf);
 int is_curwin = (curwin != NULL && curwin->w_buffer == buf);
 win_T *the_curwin = curwin;
 tabpage_T *the_curtab = curtab;

 // Make sure the buffer isn't closed by autocommands.
 buf->b_locked++;
 buf->b_locked_split++;

 bufref_T bufref;
 set_bufref(&bufref, buf);

 if (buf->terminal) {
   buf_close_terminal(buf);
 }

 buf_updates_unload(buf, false);

 if ((buf->b_ml.ml_mfp != NULL)
     && apply_autocmds(EVENT_BUFUNLOAD, buf->b_fname, buf->b_fname, false, buf)
     && !bufref_valid(&bufref)) {
   // Autocommands deleted the buffer.
   return;
 }
 if ((flags & BFA_DEL)
     && buf->b_p_bl
     && apply_autocmds(EVENT_BUFDELETE, buf->b_fname, buf->b_fname, false, buf)
     && !bufref_valid(&bufref)) {
   // Autocommands may delete the buffer.
   return;
 }
 if ((flags & BFA_WIPE)
     && apply_autocmds(EVENT_BUFWIPEOUT, buf->b_fname, buf->b_fname, false,
                       buf)
     && !bufref_valid(&bufref)) {
   // Autocommands may delete the buffer.
   return;
 }
 buf->b_locked--;
 buf->b_locked_split--;

 // If the buffer was in curwin and the window has changed, go back to that
 // window, if it still exists.  This avoids that ":edit x" triggering a
 // "tabnext" BufUnload autocmd leaves a window behind without a buffer.
 if (is_curwin && curwin != the_curwin && win_valid_any_tab(the_curwin)) {
   block_autocmds();
   goto_tabpage_win(the_curtab, the_curwin);
   unblock_autocmds();
 }
 // autocmds may abort script processing
 if ((flags & BFA_IGNORE_ABORT) == 0 && aborting()) {
   return;
 }

 // It's possible that autocommands change curbuf to the one being deleted.
 // This might cause curbuf to be deleted unexpectedly.  But in some cases
 // it's OK to delete the curbuf, because a new one is obtained anyway.
 // Therefore only return if curbuf changed to the deleted buffer.
 if (buf == curbuf && !is_curbuf) {
   return;
 }
 diff_buf_delete(buf);             // Can't use 'diff' for unloaded buffer.
 // Remove any ownsyntax, unless exiting.
 if (curwin != NULL && curwin->w_buffer == buf) {
   reset_synblock(curwin);
 }

 // No folds in an empty buffer.
 FOR_ALL_TAB_WINDOWS(tp, win) {
   if (win->w_buffer == buf) {
     clearFolding(win);
   }
 }

 // Autocommands may have opened another terminal. Block them this time.
 if (buf->terminal) {
   block_autocmds();
   buf_close_terminal(buf);
   unblock_autocmds();
 }

 ml_close(buf, true);              // close and delete the memline/memfile
 buf->b_ml.ml_line_count = 0;      // no lines in buffer
 if ((flags & BFA_KEEP_UNDO) == 0) {
   // free the memory allocated for undo
   // and reset all undo information
   u_clearallandblockfree(buf);
 }
 syntax_clear(&buf->b_s);          // reset syntax info
 buf->b_flags &= ~BF_READERR;      // a read error is no longer relevant
}

/// Free a buffer structure and the things it contains related to the buffer
/// itself (not the file, that must have been done already).
static void free_buffer(buf_T *buf)
{
 pmap_del(int)(&buffer_handles, buf->b_fnum, NULL);
 buf_free_count++;
 // b:changedtick uses an item in buf_T.
 free_buffer_stuff(buf, kBffClearWinInfo);
 if (buf->b_vars->dv_refcount > DO_NOT_FREE_CNT) {
   tv_dict_add(buf->b_vars,
               tv_dict_item_copy((dictitem_T *)(&buf->changedtick_di)));
 }
 unref_var_dict(buf->b_vars);
 aubuflocal_remove(buf);
 xfree(buf->additional_data);
 xfree(buf->b_prompt_text);
 kv_destroy(buf->b_wininfo);
 callback_free(&buf->b_prompt_callback);
 callback_free(&buf->b_prompt_interrupt);
 clear_fmark(&buf->b_last_cursor, 0);
 clear_fmark(&buf->b_last_insert, 0);
 clear_fmark(&buf->b_last_change, 0);
 clear_fmark(&buf->b_prompt_start, 0);
 for (size_t i = 0; i < NMARKS; i++) {
   free_fmark(buf->b_namedm[i]);
 }
 for (int i = 0; i < buf->b_changelistlen; i++) {
   free_fmark(buf->b_changelist[i]);
 }
 if (autocmd_busy) {
   // Do not free the buffer structure while autocommands are executing,
   // it's still needed. Free it when autocmd_busy is reset.
   CLEAR_FIELD(buf->b_namedm);
   CLEAR_FIELD(buf->b_changelist);
   buf->b_next = au_pending_free_buf;
   au_pending_free_buf = buf;
 } else {
   xfree(buf);
   if (curbuf == buf) {
     curbuf = NULL;  // make clear it's not to be used
   }
 }
}

/// Free the b_wininfo list for buffer "buf".
static void clear_wininfo(buf_T *buf)
{
 for (size_t i = 0; i < kv_size(buf->b_wininfo); i++) {
   free_wininfo(kv_A(buf->b_wininfo, i), buf);
 }
 kv_size(buf->b_wininfo) = 0;
}

/// Free stuff in the buffer for ":bdel" and when wiping out the buffer.
///
/// @param buf  Buffer pointer
/// @param free_flags  BufFreeFlags
static void free_buffer_stuff(buf_T *buf, int free_flags)
{
 if (free_flags & kBffClearWinInfo) {
   clear_wininfo(buf);                 // including window-local options
   free_buf_options(buf, true);
   ga_clear(&buf->b_s.b_langp);
 }
 {
   // Avoid losing b:changedtick when deleting buffer: clearing variables
   // implies using clear_tv() on b:changedtick and that sets changedtick to
   // zero.
   hashitem_T *const changedtick_hi = hash_find(&buf->b_vars->dv_hashtab, "changedtick");
   assert(changedtick_hi != NULL);
   hash_remove(&buf->b_vars->dv_hashtab, changedtick_hi);
 }
 vars_clear(&buf->b_vars->dv_hashtab);   // free all internal variables
 hash_init(&buf->b_vars->dv_hashtab);
 if (free_flags & kBffInitChangedtick) {
   buf_init_changedtick(buf);
 }
 uc_clear(&buf->b_ucmds);               // clear local user commands
 extmark_free_all(buf);                 // delete any extmarks
 map_clear_mode(buf, MAP_ALL_MODES, true, false);  // clear local mappings
 map_clear_mode(buf, MAP_ALL_MODES, true, true);   // clear local abbrevs
 XFREE_CLEAR(buf->b_start_fenc);

 buf_free_callbacks(buf);
}

/// Go to another buffer.  Handles the result of the ATTENTION dialog.
void goto_buffer(exarg_T *eap, int start, int dir, int count)
{
 const int save_sea = swap_exists_action;
 bool skip_help_buf;

 switch (eap->cmdidx) {
 case CMD_bnext:
 case CMD_sbnext:
 case CMD_bNext:
 case CMD_bprevious:
 case CMD_sbNext:
 case CMD_sbprevious:
   skip_help_buf = true;
   break;
 default:
   skip_help_buf = false;
   break;
 }

 bufref_T old_curbuf;
 set_bufref(&old_curbuf, curbuf);

 if (swap_exists_action == SEA_NONE) {
   swap_exists_action = SEA_DIALOG;
 }
 (void)do_buffer_ext(*eap->cmd == 's' ? DOBUF_SPLIT : DOBUF_GOTO, start, dir, count,
                     (eap->forceit ? DOBUF_FORCEIT : 0) |
                     (skip_help_buf ? DOBUF_SKIPHELP : 0));

 if (swap_exists_action == SEA_QUIT && *eap->cmd == 's') {
   cleanup_T cs;

   // Reset the error/interrupt/exception state here so that
   // aborting() returns false when closing a window.
   enter_cleanup(&cs);

   // Quitting means closing the split window, nothing else.
   win_close(curwin, true, false);
   swap_exists_action = save_sea;
   swap_exists_did_quit = true;

   // Restore the error/interrupt/exception state if not discarded by a
   // new aborting error, interrupt, or uncaught exception.
   leave_cleanup(&cs);
 } else {
   handle_swap_exists(&old_curbuf);
 }
}

/// Handle the situation of swap_exists_action being set.
///
/// It is allowed for "old_curbuf" to be NULL or invalid.
///
/// @param old_curbuf The buffer to check for.
void handle_swap_exists(bufref_T *old_curbuf)
{
 cleanup_T cs;
 OptInt old_tw = curbuf->b_p_tw;
 buf_T *buf;

 if (swap_exists_action == SEA_QUIT) {
   // Reset the error/interrupt/exception state here so that
   // aborting() returns false when closing a buffer.
   enter_cleanup(&cs);

   // User selected Quit at ATTENTION prompt.  Go back to previous
   // buffer.  If that buffer is gone or the same as the current one,
   // open a new, empty buffer.
   swap_exists_action = SEA_NONE;      // don't want it again
   swap_exists_did_quit = true;
   close_buffer(curwin, curbuf, DOBUF_UNLOAD, false, false);
   if (old_curbuf == NULL
       || !bufref_valid(old_curbuf)
       || old_curbuf->br_buf == curbuf) {
     // Block autocommands here because curwin->w_buffer is NULL.
     block_autocmds();
     buf = buflist_new(NULL, NULL, 1, BLN_CURBUF | BLN_LISTED);
     unblock_autocmds();
   } else {
     buf = old_curbuf->br_buf;
   }
   if (buf != NULL) {
     enter_buffer(buf);

     if (old_tw != curbuf->b_p_tw) {
       check_colorcolumn(NULL, curwin);
     }
   }
   // If "old_curbuf" is NULL we are in big trouble here...

   // Restore the error/interrupt/exception state if not discarded by a
   // new aborting error, interrupt, or uncaught exception.
   leave_cleanup(&cs);
 } else if (swap_exists_action == SEA_RECOVER) {
   // Reset the error/interrupt/exception state here so that
   // aborting() returns false when closing a buffer.
   enter_cleanup(&cs);

   // User selected Recover at ATTENTION prompt.
   msg_scroll = true;
   ml_recover(false);
   msg_puts("\n");     // don't overwrite the last message
   cmdline_row = msg_row;
   do_modelines(0);

   // Restore the error/interrupt/exception state if not discarded by a
   // new aborting error, interrupt, or uncaught exception.
   leave_cleanup(&cs);
 }
 swap_exists_action = SEA_NONE;
}

/// do_bufdel() - delete or unload buffer(s)
///
/// addr_count == 0: ":bdel" - delete current buffer
/// addr_count == 1: ":N bdel" or ":bdel N [N ..]" - first delete
///                  buffer "end_bnr", then any other arguments.
/// addr_count == 2: ":N,N bdel" - delete buffers in range
///
/// command can be DOBUF_UNLOAD (":bunload"), DOBUF_WIPE (":bwipeout") or
/// DOBUF_DEL (":bdel")
///
/// @param arg  pointer to extra arguments
/// @param start_bnr  first buffer number in a range
/// @param end_bnr  buffer nr or last buffer nr in a range
///
/// @return  error message or NULL
char *do_bufdel(int command, char *arg, int addr_count, int start_bnr, int end_bnr, int forceit)
{
 int do_current = 0;             // delete current buffer?
 int deleted = 0;                // number of buffers deleted
 char *errormsg = NULL;          // return value
 int bnr;                        // buffer number

 if (addr_count == 0) {
   do_buffer(command, DOBUF_CURRENT, FORWARD, 0, forceit);
 } else {
   if (addr_count == 2) {
     if (*arg) {               // both range and argument is not allowed
       return ex_errmsg(e_trailing_arg, arg);
     }
     bnr = start_bnr;
   } else {    // addr_count == 1
     bnr = end_bnr;
   }

   for (; !got_int; os_breakcheck()) {
     // delete the current buffer last, otherwise when the
     // current buffer is deleted, the next buffer becomes
     // the current one and will be loaded, which may then
     // also be deleted, etc.
     if (bnr == curbuf->b_fnum) {
       do_current = bnr;
     } else if (do_buffer(command, DOBUF_FIRST, FORWARD, bnr,
                          forceit) == OK) {
       deleted++;
     }

     // find next buffer number to delete/unload
     if (addr_count == 2) {
       if (++bnr > end_bnr) {
         break;
       }
     } else {    // addr_count == 1
       arg = skipwhite(arg);
       if (*arg == NUL) {
         break;
       }
       if (!ascii_isdigit(*arg)) {
         char *p = skiptowhite_esc(arg);
         bnr = buflist_findpat(arg, p, command == DOBUF_WIPE, false, false);
         if (bnr < 0) {                    // failed
           break;
         }
         arg = p;
       } else {
         bnr = getdigits_int(&arg, false, 0);
       }
     }
   }
   if (!got_int && do_current
       && do_buffer(command, DOBUF_FIRST,
                    FORWARD, do_current, forceit) == OK) {
     deleted++;
   }

   if (deleted == 0) {
     if (command == DOBUF_UNLOAD) {
       xstrlcpy(IObuff, _("E515: No buffers were unloaded"), IOSIZE);
     } else if (command == DOBUF_DEL) {
       xstrlcpy(IObuff, _("E516: No buffers were deleted"), IOSIZE);
     } else {
       xstrlcpy(IObuff, _("E517: No buffers were wiped out"), IOSIZE);
     }
     errormsg = IObuff;
   } else if (deleted >= p_report) {
     if (command == DOBUF_UNLOAD) {
       smsg(0, NGETTEXT("%d buffer unloaded", "%d buffers unloaded", deleted),
            deleted);
     } else if (command == DOBUF_DEL) {
       smsg(0, NGETTEXT("%d buffer deleted", "%d buffers deleted", deleted),
            deleted);
     } else {
       smsg(0, NGETTEXT("%d buffer wiped out", "%d buffers wiped out", deleted),
            deleted);
     }
   }
 }

 return errormsg;
}

/// Make the current buffer empty.
/// Used when it is wiped out and it's the last buffer.
static int empty_curbuf(bool close_others, int forceit, int action)
{
 buf_T *buf = curbuf;

 if (action == DOBUF_UNLOAD) {
   emsg(_("E90: Cannot unload last buffer"));
   return FAIL;
 }

 bufref_T bufref;
 set_bufref(&bufref, buf);

 if (close_others) {
   bool can_close_all_others = true;
   if (curwin->w_floating) {
     // Closing all other windows with this buffer may leave only floating windows.
     can_close_all_others = false;
     for (win_T *wp = firstwin; !wp->w_floating; wp = wp->w_next) {
       if (wp->w_buffer != curbuf) {
         // Found another non-floating window with a different (probably unlisted) buffer.
         // Closing all other windows with this buffer is fine in this case.
         can_close_all_others = true;
         break;
       }
     }
   }
   // If it is fine to close all other windows with this buffer, keep the current window and
   // close any other windows with this buffer, then make it empty.
   // Otherwise close_windows() will refuse to close the last non-floating window, so allow it
   // to close the current window instead.
   close_windows(buf, can_close_all_others);
 }

 setpcmark();
 int retval = do_ecmd(0, NULL, NULL, NULL, ECMD_ONE, forceit ? ECMD_FORCEIT : 0, curwin);

 // do_ecmd() may create a new buffer, then we have to delete
 // the old one.  But do_ecmd() may have done that already, check
 // if the buffer still exists.
 if (buf != curbuf && bufref_valid(&bufref) && buf->b_nwindows == 0) {
   close_buffer(NULL, buf, action, false, false);
 }

 if (!close_others) {
   need_fileinfo = false;
 }

 return retval;
}

/// Implementation of the commands for the buffer list.
///
/// action == DOBUF_GOTO     go to specified buffer
/// action == DOBUF_SPLIT    split window and go to specified buffer
/// action == DOBUF_UNLOAD   unload specified buffer(s)
/// action == DOBUF_DEL      delete specified buffer(s) from buffer list
/// action == DOBUF_WIPE     delete specified buffer(s) really
///
/// start == DOBUF_CURRENT   go to "count" buffer from current buffer
/// start == DOBUF_FIRST     go to "count" buffer from first buffer
/// start == DOBUF_LAST      go to "count" buffer from last buffer
/// start == DOBUF_MOD       go to "count" modified buffer from current buffer
///
/// @param dir  FORWARD or BACKWARD
/// @param count  buffer number or number of buffers
/// @param flags  see @ref dobuf_flags_value
///
/// @return  FAIL or OK.
static int do_buffer_ext(int action, int start, int dir, int count, int flags)
{
 buf_T *buf;
 buf_T *bp;
 bool update_jumplist = true;
 bool unload = (action == DOBUF_UNLOAD || action == DOBUF_DEL
                || action == DOBUF_WIPE);

 switch (start) {
 case DOBUF_FIRST:
   buf = firstbuf; break;
 case DOBUF_LAST:
   buf = lastbuf;  break;
 default:
   buf = curbuf;   break;
 }
 if (start == DOBUF_MOD) {         // find next modified buffer
   while (count-- > 0) {
     do {
       buf = buf->b_next;
       if (buf == NULL) {
         buf = firstbuf;
       }
     } while (buf != curbuf && !bufIsChanged(buf));
   }
   if (!bufIsChanged(buf)) {
     emsg(_("E84: No modified buffer found"));
     return FAIL;
   }
 } else if (start == DOBUF_FIRST && count) {  // find specified buffer number
   while (buf != NULL && buf->b_fnum != count) {
     buf = buf->b_next;
   }
 } else {
   const bool help_only = (flags & DOBUF_SKIPHELP) != 0 && buf->b_help;

   bp = NULL;
   while (count > 0 || (bp != buf && !unload
                        && !(help_only ? buf->b_help : buf->b_p_bl))) {
     // remember the buffer where we start, we come back there when all
     // buffers are unlisted.
     if (bp == NULL) {
       bp = buf;
     }
     buf = dir == FORWARD ? (buf->b_next != NULL ? buf->b_next : firstbuf)
                          : (buf->b_prev != NULL ? buf->b_prev : lastbuf);
     // Avoid non-help buffers if the starting point was a help buffer
     // and vice-versa.
     // Don't count unlisted buffers.
     if (unload
         || (help_only
             ? buf->b_help
             : (buf->b_p_bl && ((flags & DOBUF_SKIPHELP) == 0 || !buf->b_help)))) {
       count--;
       bp = NULL;              // use this buffer as new starting point
     }
     if (bp == buf) {
       // back where we started, didn't find anything.
       emsg(_("E85: There is no listed buffer"));
       return FAIL;
     }
   }
 }

 if (buf == NULL) {        // could not find it
   if (start == DOBUF_FIRST) {
     // don't warn when deleting
     if (!unload) {
       semsg(_(e_nobufnr), (int64_t)count);
     }
   } else if (dir == FORWARD) {
     emsg(_("E87: Cannot go beyond last buffer"));
   } else {
     emsg(_("E88: Cannot go before first buffer"));
   }
   return FAIL;
 }

 if (action == DOBUF_GOTO && buf != curbuf
     && !check_can_set_curbuf_forceit((flags & DOBUF_FORCEIT) != 0)) {
   // disallow navigating to another buffer when 'winfixbuf' is applied
   return FAIL;
 }

 if ((action == DOBUF_GOTO || action == DOBUF_SPLIT) && (buf->b_flags & BF_DUMMY)) {
   // disallow navigating to the dummy buffer
   semsg(_(e_nobufnr), count);
   return FAIL;
 }

 // delete buffer "buf" from memory and/or the list
 if (unload) {
   int forward;
   bufref_T bufref;
   if (!can_unload_buffer(buf)) {
     return FAIL;
   }
   set_bufref(&bufref, buf);

   // When unloading or deleting a buffer that's already unloaded and
   // unlisted: fail silently.
   if (action != DOBUF_WIPE && buf->b_ml.ml_mfp == NULL && !buf->b_p_bl) {
     return FAIL;
   }

   if ((flags & DOBUF_FORCEIT) == 0 && bufIsChanged(buf)) {
     if ((p_confirm || (cmdmod.cmod_flags & CMOD_CONFIRM)) && p_write) {
       dialog_changed(buf, false);
       if (!bufref_valid(&bufref)) {
         // Autocommand deleted buffer, oops! It's not changed now.
         return FAIL;
       }
       // If it's still changed fail silently, the dialog already
       // mentioned why it fails.
       if (bufIsChanged(buf)) {
         return FAIL;
       }
     } else {
       semsg(_(e_no_write_since_last_change_for_buffer_nr_add_bang_to_override),
             buf->b_fnum);
       return FAIL;
     }
   }

   if (!(flags & DOBUF_FORCEIT) && buf->terminal && terminal_running(buf->terminal)) {
     if (p_confirm || (cmdmod.cmod_flags & CMOD_CONFIRM)) {
       if (!dialog_close_terminal(buf)) {
         return FAIL;
       }
     } else {
       semsg(_("E89: %s will be killed (add ! to override)"), buf->b_fname);
       return FAIL;
     }
   }

   int buf_fnum = buf->b_fnum;

   // When closing the current buffer stop Visual mode.
   if (buf == curbuf && VIsual_active) {
     end_visual_mode();
   }

   // If deleting the last (listed) buffer, make it empty.
   // The last (listed) buffer cannot be unloaded.
   bp = NULL;
   FOR_ALL_BUFFERS(bp2) {
     if (bp2->b_p_bl && bp2 != buf) {
       bp = bp2;
       break;
     }
   }
   if (bp == NULL && buf == curbuf) {
     return empty_curbuf(true, (flags & DOBUF_FORCEIT), action);
   }

   // If the deleted buffer is the current one, close the current window
   // (unless it's the only non-floating window).
   // When the autocommand window is involved win_close() may need to print an error message.
   // Repeat this so long as we end up in a window with this buffer.
   while (buf == curbuf
          && !(win_locked(curwin) || curwin->w_buffer->b_locked > 0)
          && (is_aucmd_win(lastwin) || !last_window(curwin))) {
     if (win_close(curwin, false, false) == FAIL) {
       break;
     }
   }

   // If the buffer to be deleted is not the current one, delete it here.
   if (buf != curbuf) {
     if (jop_flags & kOptJopFlagClean) {
       // Remove the buffer to be deleted from the jump list.
       mark_jumplist_forget_file(curwin, buf_fnum);
     }

     close_windows(buf, false);

     if (buf != curbuf && bufref_valid(&bufref) && buf->b_nwindows <= 0) {
       close_buffer(NULL, buf, action, false, false);
     }
     return OK;
   }

   // Deleting the current buffer: Need to find another buffer to go to.
   // There should be another, otherwise it would have been handled
   // above.  However, autocommands may have deleted all buffers.
   // First use au_new_curbuf.br_buf, if it is valid.
   // Then prefer the buffer we most recently visited.
   // Else try to find one that is loaded, after the current buffer,
   // then before the current buffer.
   // Finally use any buffer.  Skip buffers that are closing throughout.
   buf = NULL;  // Selected buffer.
   bp = NULL;   // Used when no loaded buffer found.
   if (au_new_curbuf.br_buf != NULL && bufref_valid(&au_new_curbuf)
       && !au_new_curbuf.br_buf->b_locked_split) {
     buf = au_new_curbuf.br_buf;
   } else if (curwin->w_jumplistlen > 0) {
     if (jop_flags & kOptJopFlagClean) {
       // Remove the buffer from the jump list.
       mark_jumplist_forget_file(curwin, buf_fnum);
     }

     // It's possible that we removed all jump list entries, in that case we need to try another
     // approach
     if (curwin->w_jumplistlen > 0) {
       int jumpidx = curwin->w_jumplistidx;

       if (jop_flags & kOptJopFlagClean) {
         // If the index is the same as the length, the current position was not yet added to the
         // jump list. So we can safely go back to the last entry and search from there.
         if (jumpidx == curwin->w_jumplistlen) {
           jumpidx = curwin->w_jumplistidx = curwin->w_jumplistlen - 1;
         }
       } else {
         jumpidx--;
         if (jumpidx < 0) {
           jumpidx = curwin->w_jumplistlen - 1;
         }
       }

       forward = jumpidx;
       while ((jop_flags & kOptJopFlagClean) || jumpidx != curwin->w_jumplistidx) {
         buf = buflist_findnr(curwin->w_jumplist[jumpidx].fmark.fnum);

         if (buf != NULL) {
           // Skip current and unlisted bufs.  Also skip a quickfix
           // or closing buffer, it might be deleted soon.
           if (buf == curbuf || !buf->b_p_bl || bt_quickfix(buf)
               || buf->b_locked_split) {
             buf = NULL;
           } else if (buf->b_ml.ml_mfp == NULL) {
             // skip unloaded buf, but may keep it for later
             if (bp == NULL) {
               bp = buf;
             }
             buf = NULL;
           }
         }
         if (buf != NULL) {         // found a valid buffer: stop searching
           if (jop_flags & kOptJopFlagClean) {
             curwin->w_jumplistidx = jumpidx;
             update_jumplist = false;
           }
           break;
         }
         // advance to older entry in jump list
         if (!jumpidx && curwin->w_jumplistidx == curwin->w_jumplistlen) {
           break;
         }
         if (--jumpidx < 0) {
           jumpidx = curwin->w_jumplistlen - 1;
         }
         if (jumpidx == forward) {               // List exhausted for sure
           break;
         }
       }
     }
   }

   if (buf == NULL) {          // No previous buffer, Try 2'nd approach
     forward = true;
     buf = curbuf->b_next;
     while (true) {
       if (buf == NULL) {
         if (!forward) {               // tried both directions
           break;
         }
         buf = curbuf->b_prev;
         forward = false;
         continue;
       }
       // in non-help buffer, try to skip help buffers, and vv
       if (buf->b_help == curbuf->b_help && buf->b_p_bl
           && !bt_quickfix(buf) && !buf->b_locked_split) {
         if (buf->b_ml.ml_mfp != NULL) {           // found loaded buffer
           break;
         }
         if (bp == NULL) {             // remember unloaded buf for later
           bp = buf;
         }
       }
       buf = forward ? buf->b_next : buf->b_prev;
     }
   }
   if (buf == NULL) {          // No loaded buffer, use unloaded one
     buf = bp;
   }
   if (buf == NULL) {          // No loaded buffer, find listed one
     FOR_ALL_BUFFERS(buf2) {
       if (buf2->b_p_bl && buf2 != curbuf && !bt_quickfix(buf2) && !buf2->b_locked_split) {
         buf = buf2;
         break;
       }
     }
   }
   if (buf == NULL) {          // Still no buffer, just take one
     buf = curbuf->b_next != NULL ? curbuf->b_next : curbuf->b_prev;
     if (bt_quickfix(buf) || (buf != curbuf && buf->b_locked_split)) {
       buf = NULL;
     }
   }
 }

 if (buf == NULL) {
   // Autocommands must have wiped out all other buffers.  Only option
   // now is to make the current buffer empty.
   return empty_curbuf(false, (flags & DOBUF_FORCEIT), action);
 }

 // make "buf" the current buffer
 // If 'switchbuf' is set jump to the window containing "buf".
 if (action == DOBUF_SPLIT && swbuf_goto_win_with_buf(buf) != NULL) {
   return OK;
 }
 // Whether splitting or not, don't open a closing buffer in more windows.
 if (buf != curbuf && buf->b_locked_split) {
   emsg(_(e_cannot_switch_to_a_closing_buffer));
   return FAIL;
 }
 if (action == DOBUF_SPLIT && win_split(0, 0) == FAIL) {  // split window first
   return FAIL;
 }

 // go to current buffer - nothing to do
 if (buf == curbuf) {
   return OK;
 }

 // Check if the current buffer may be abandoned.
 if (action == DOBUF_GOTO && !can_abandon(curbuf, (flags & DOBUF_FORCEIT))) {
   if ((p_confirm || (cmdmod.cmod_flags & CMOD_CONFIRM)) && p_write) {
     bufref_T bufref;
     set_bufref(&bufref, buf);
     dialog_changed(curbuf, false);
     if (!bufref_valid(&bufref)) {
       // Autocommand deleted buffer, oops!
       return FAIL;
     }
   }
   if (bufIsChanged(curbuf)) {
     no_write_message();
     return FAIL;
   }
 }

 // Go to the other buffer.
 set_curbuf(buf, action, update_jumplist);

 if (action == DOBUF_SPLIT) {
   RESET_BINDING(curwin);      // reset 'scrollbind' and 'cursorbind'
 }

 if (aborting()) {         // autocmds may abort script processing
   return FAIL;
 }

 return OK;
}

int do_buffer(int action, int start, int dir, int count, int forceit)
{
 return do_buffer_ext(action, start, dir, count, forceit ? DOBUF_FORCEIT : 0);
}

/// Set current buffer to "buf".  Executes autocommands and closes current
/// buffer.
///
/// @param action  tells how to close the current buffer:
///                DOBUF_GOTO       free or hide it
///                DOBUF_SPLIT      nothing
///                DOBUF_UNLOAD     unload it
///                DOBUF_DEL        delete it
///                DOBUF_WIPE       wipe it out
void set_curbuf(buf_T *buf, int action, bool update_jumplist)
{
 buf_T *prevbuf;
 int unload = (action == DOBUF_UNLOAD || action == DOBUF_DEL
               || action == DOBUF_WIPE);
 OptInt old_tw = curbuf->b_p_tw;
 const int last_winid = get_last_winid();

 if (update_jumplist) {
   setpcmark();
 }

 if ((cmdmod.cmod_flags & CMOD_KEEPALT) == 0) {
   curwin->w_alt_fnum = curbuf->b_fnum;     // remember alternate file
 }
 buflist_altfpos(curwin);                       // remember curpos

 // Don't restart Select mode after switching to another buffer.
 VIsual_reselect = false;

 // close_windows() or apply_autocmds() may change curbuf and wipe out "buf"
 prevbuf = curbuf;
 bufref_T newbufref;
 bufref_T prevbufref;
 set_bufref(&prevbufref, prevbuf);
 set_bufref(&newbufref, buf);
 const int prev_nwindows = prevbuf->b_nwindows;

 // Autocommands may delete the current buffer and/or the buffer we want to
 // go to.  In those cases don't close the buffer.
 if (!apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, false, curbuf)
     || (bufref_valid(&prevbufref) && bufref_valid(&newbufref)
         && !aborting())) {
   if (prevbuf == curwin->w_buffer) {
     reset_synblock(curwin);
   }
   // autocommands may have opened a new window
   // with prevbuf, grr
   if (unload
       || (prev_nwindows <= 1 && last_winid != get_last_winid()
           && action == DOBUF_GOTO && !buf_hide(prevbuf))) {
     close_windows(prevbuf, false);
   }
   if (bufref_valid(&prevbufref) && !aborting()) {
     win_T *previouswin = curwin;

     // Do not sync when in Insert mode and the buffer is open in
     // another window, might be a timer doing something in another
     // window.
     if (prevbuf == curbuf && ((State & MODE_INSERT) == 0 || curbuf->b_nwindows <= 1)) {
       u_sync(false);
     }
     close_buffer(prevbuf == curwin->w_buffer ? curwin : NULL,
                  prevbuf,
                  unload
                  ? action
                  : (action == DOBUF_GOTO && !buf_hide(prevbuf)
                     && !bufIsChanged(prevbuf)) ? DOBUF_UNLOAD : 0,
                  false, false);
     if (curwin != previouswin && win_valid(previouswin)) {
       // autocommands changed curwin, Grr!
       curwin = previouswin;
     }
   }
 }
 // An autocommand may have deleted "buf", already entered it (e.g., when
 // it did ":bunload") or aborted the script processing!
 // If curwin->w_buffer is null, enter_buffer() will make it valid again
 bool valid = buf_valid(buf);
 if ((valid && buf != curbuf && !aborting()) || curwin->w_buffer == NULL) {
   // autocommands changed curbuf and we will move to another
   // buffer soon, so decrement curbuf->b_nwindows
   if (curbuf != NULL && prevbuf != curbuf) {
     curbuf->b_nwindows--;
   }
   // If the buffer is not valid but curwin->w_buffer is NULL we must
   // enter some buffer.  Using the last one is hopefully OK.
   enter_buffer(valid ? buf : lastbuf);
   if (old_tw != curbuf->b_p_tw) {
     check_colorcolumn(NULL, curwin);
   }
 }

 if (bufref_valid(&prevbufref) && prevbuf->terminal != NULL) {
   terminal_check_size(prevbuf->terminal);
 }
}

/// Enter a new current buffer.
/// Old curbuf must have been abandoned already!  This also means "curbuf" may
/// be pointing to freed memory.
static void enter_buffer(buf_T *buf)
{
 // when closing the current buffer stop Visual mode
 if (VIsual_active
#if defined(EXITFREE)
     && !entered_free_all_mem
#endif
     ) {
   end_visual_mode();
 }

 // Get the buffer in the current window.
 curwin->w_buffer = buf;
 curbuf = buf;
 curbuf->b_nwindows++;

 // Copy buffer and window local option values.  Not for a help buffer.
 buf_copy_options(buf, BCO_ENTER | BCO_NOHELP);
 if (!buf->b_help) {
   get_winopts(buf);
 } else {
   // Remove all folds in the window.
   clearFolding(curwin);
 }
 foldUpdateAll(curwin);        // update folds (later).

 if (curwin->w_p_diff) {
   diff_buf_add(curbuf);
 }

 curwin->w_s = &(curbuf->b_s);

 // Cursor on first line by default.
 curwin->w_cursor.lnum = 1;
 curwin->w_cursor.col = 0;
 curwin->w_cursor.coladd = 0;
 curwin->w_set_curswant = true;
 curwin->w_topline_was_set = false;

 // mark cursor position as being invalid
 curwin->w_valid = 0;

 // Make sure the buffer is loaded.
 if (curbuf->b_ml.ml_mfp == NULL) {    // need to load the file
   // If there is no filetype, allow for detecting one.  Esp. useful for
   // ":ball" used in an autocommand.  If there already is a filetype we
   // might prefer to keep it.
   if (*curbuf->b_p_ft == NUL) {
     curbuf->b_did_filetype = false;
   }

   open_buffer(false, NULL, 0);
 } else {
   if (!msg_silent && !shortmess(SHM_FILEINFO)) {
     need_fileinfo = true;             // display file info after redraw
   }
   // check if file changed
   buf_check_timestamp(curbuf);

   curwin->w_topline = 1;
   curwin->w_topfill = 0;
   apply_autocmds(EVENT_BUFENTER, NULL, NULL, false, curbuf);
   apply_autocmds(EVENT_BUFWINENTER, NULL, NULL, false, curbuf);
 }

 // If autocommands did not change the cursor position, restore cursor lnum
 // and possibly cursor col.
 if (curwin->w_cursor.lnum == 1 && inindent(0)) {
   buflist_getfpos();
 }

 check_arg_idx(curwin);                // check for valid arg_idx
 maketitle();
 // when autocmds didn't change it
 if (curwin->w_topline == 1 && !curwin->w_topline_was_set) {
   scroll_cursor_halfway(curwin, false, false);  // redisplay at correct position
 }

 // Change directories when the 'acd' option is set.
 do_autochdir();

 if (curbuf->b_kmap_state & KEYMAP_INIT) {
   keymap_init();
 }
 // May need to set the spell language.  Can only do this after the buffer
 // has been properly setup.
 if (!curbuf->b_help && curwin->w_p_spell && *curwin->w_s->b_p_spl != NUL) {
   parse_spelllang(curwin);
 }
 curbuf->b_last_used = time(NULL);

 if (curbuf->terminal != NULL) {
   terminal_check_size(curbuf->terminal);
 }

 redraw_later(curwin, UPD_NOT_VALID);
}

/// Change to the directory of the current buffer.
/// Don't do this while still starting up.
void do_autochdir(void)
{
 if (p_acd) {
   if (starting == 0
       && curbuf->b_ffname != NULL
       && vim_chdirfile(curbuf->b_ffname, kCdCauseAuto) == OK) {
     last_chdir_reason = "autochdir";
     shorten_fnames(true);
   }
 }
}

void no_write_message_buf(buf_T *buf)
{
 if (buf->terminal
     && channel_job_running((uint64_t)buf->b_p_channel)) {
   emsg(_(e_job_still_running_add_bang_to_end_the_job));
 } else {
   semsg(_(e_no_write_since_last_change_for_buffer_nr_add_bang_to_override),
         buf->b_fnum);
 }
}

void no_write_message(void)
{
 if (curbuf->terminal
     && channel_job_running((uint64_t)curbuf->b_p_channel)) {
   emsg(_(e_job_still_running_add_bang_to_end_the_job));
 } else {
   emsg(_(e_no_write_since_last_change_add_bang_to_override));
 }
}

void no_write_message_nobang(const buf_T *const buf)
 FUNC_ATTR_NONNULL_ALL
{
 if (buf->terminal
     && channel_job_running((uint64_t)buf->b_p_channel)) {
   emsg(_(e_job_still_running));
 } else {
   emsg(_(e_no_write_since_last_change));
 }
}

//
// functions for dealing with the buffer list
//

/// Initialize b:changedtick and changedtick_val attribute
///
/// @param[out]  buf  Buffer to initialize for.
static inline void buf_init_changedtick(buf_T *const buf)
 FUNC_ATTR_ALWAYS_INLINE FUNC_ATTR_NONNULL_ALL
{
 STATIC_ASSERT(sizeof("changedtick") <= sizeof(buf->changedtick_di.di_key),
               "buf->changedtick_di cannot hold large enough keys");
 buf->changedtick_di = (ChangedtickDictItem) {
   .di_flags = DI_FLAGS_RO|DI_FLAGS_FIX,  // Must not include DI_FLAGS_ALLOC.
   .di_tv = (typval_T) {
     .v_type = VAR_NUMBER,
     .v_lock = VAR_FIXED,
     .vval.v_number = buf_get_changedtick(buf),
   },
   .di_key = "changedtick",
 };
 tv_dict_add(buf->b_vars, (dictitem_T *)&buf->changedtick_di);
}

/// Add a file name to the buffer list.
/// If the same file name already exists return a pointer to that buffer.
/// If it does not exist, or if fname == NULL, a new entry is created.
/// If (flags & BLN_CURBUF) is true, may use current buffer.
/// If (flags & BLN_LISTED) is true, add new buffer to buffer list.
/// If (flags & BLN_DUMMY) is true, don't count it as a real buffer.
/// If (flags & BLN_NEW) is true, don't use an existing buffer.
/// If (flags & BLN_NOOPT) is true, don't copy options from the current buffer
///                                 if the buffer already exists.
/// This is the ONLY way to create a new buffer.
///
/// @param ffname_arg  full path of fname or relative
/// @param sfname_arg  short fname or NULL
/// @param lnum   preferred cursor line
/// @param flags  BLN_ defines
/// @param bufnr
///
/// @return  pointer to the buffer
buf_T *buflist_new(char *ffname_arg, char *sfname_arg, linenr_T lnum, int flags)
{
 char *ffname = ffname_arg;
 char *sfname = sfname_arg;
 buf_T *buf;

 fname_expand(curbuf, &ffname, &sfname);       // will allocate ffname

 // If the file name already exists in the list, update the entry.

 // We can use inode numbers when the file exists.  Works better
 // for hard links.
 FileID file_id;
 bool file_id_valid = (sfname != NULL && os_fileid(sfname, &file_id));
 if (ffname != NULL && !(flags & (BLN_DUMMY | BLN_NEW))
     && (buf = buflist_findname_file_id(ffname, &file_id, file_id_valid)) != NULL) {
   xfree(ffname);
   if (lnum != 0) {
     buflist_setfpos(buf, (flags & BLN_NOCURWIN) ? NULL : curwin,
                     lnum, 0, false);
   }
   if ((flags & BLN_NOOPT) == 0) {
     // Copy the options now, if 'cpo' doesn't have 's' and not done already.
     buf_copy_options(buf, 0);
   }
   if ((flags & BLN_LISTED) && !buf->b_p_bl) {
     buf->b_p_bl = true;
     bufref_T bufref;
     set_bufref(&bufref, buf);
     if (!(flags & BLN_DUMMY)) {
       if (apply_autocmds(EVENT_BUFADD, NULL, NULL, false, buf)
           && !bufref_valid(&bufref)) {
         return NULL;
       }
     }
   }
   return buf;
 }

 // If the current buffer has no name and no contents, use the current
 // buffer.    Otherwise: Need to allocate a new buffer structure.
 //
 // This is the ONLY place where a new buffer structure is allocated!
 // (A spell file buffer is allocated in spell.c, but that's not a normal
 // buffer.)
 buf = NULL;
 if ((flags & BLN_CURBUF) && curbuf_reusable()) {
   bufref_T bufref;

   assert(curbuf != NULL);
   buf = curbuf;
   set_bufref(&bufref, buf);
   trigger_undo_ftplugin(buf, curwin);
   // It's like this buffer is deleted.  Watch out for autocommands that
   // change curbuf!  If that happens, allocate a new buffer anyway.
   buf_freeall(buf, BFA_WIPE | BFA_DEL);
   if (aborting()) {           // autocmds may abort script processing
     xfree(ffname);
     return NULL;
   }
   if (!bufref_valid(&bufref)) {
     buf = NULL;  // buf was deleted; allocate a new buffer
   }
 }
 if (buf != curbuf || curbuf == NULL) {
   buf = xcalloc(1, sizeof(buf_T));
   // init b: variables
   buf->b_vars = tv_dict_alloc();
   init_var_dict(buf->b_vars, &buf->b_bufvar, VAR_SCOPE);
   buf_init_changedtick(buf);
 }

 if (ffname != NULL) {
   buf->b_ffname = ffname;
   buf->b_sfname = xstrdup(sfname);
 }

 clear_wininfo(buf);
 WinInfo *curwin_info = xcalloc(1, sizeof(WinInfo));
 kv_push(buf->b_wininfo, curwin_info);

 if (buf == curbuf) {
   free_buffer_stuff(buf, kBffInitChangedtick);  // delete local vars et al.

   // Init the options.
   buf->b_p_initialized = false;
   buf_copy_options(buf, BCO_ENTER);

   // need to reload lmaps and set b:keymap_name
   curbuf->b_kmap_state |= KEYMAP_INIT;
 } else {
   // put new buffer at the end of the buffer list
   buf->b_next = NULL;
   if (firstbuf == NULL) {             // buffer list is empty
     buf->b_prev = NULL;
     firstbuf = buf;
   } else {                            // append new buffer at end of list
     lastbuf->b_next = buf;
     buf->b_prev = lastbuf;
   }
   lastbuf = buf;

   buf->b_fnum = top_file_num++;
   pmap_put(int)(&buffer_handles, buf->b_fnum, buf);
   if (top_file_num < 0) {  // wrap around (may cause duplicates)
     emsg(_("W14: Warning: List of file names overflow"));
     if (emsg_silent == 0 && !in_assert_fails) {
       msg_delay(3001, true);  // make sure it is noticed
     }
     top_file_num = 1;
   }

   // Always copy the options from the current buffer.
   buf_copy_options(buf, BCO_ALWAYS);
 }

 curwin_info->wi_mark = (fmark_T)INIT_FMARK;
 curwin_info->wi_mark.mark.lnum = lnum;
 curwin_info->wi_win = curwin;

 hash_init(&buf->b_s.b_keywtab);
 hash_init(&buf->b_s.b_keywtab_ic);

 buf->b_fname = buf->b_sfname;
 if (!file_id_valid) {
   buf->file_id_valid = false;
 } else {
   buf->file_id_valid = true;
   buf->file_id = file_id;
 }
 buf->b_u_synced = true;
 buf->b_flags = BF_CHECK_RO | BF_NEVERLOADED;
 if (flags & BLN_DUMMY) {
   buf->b_flags |= BF_DUMMY;
 }
 buf_clear_file(buf);
 clrallmarks(buf, 0);                  // clear marks
 fmarks_check_names(buf);              // check file marks for this file
 buf->b_p_bl = (flags & BLN_LISTED) ? true : false;    // init 'buflisted'
 kv_destroy(buf->update_channels);
 kv_init(buf->update_channels);
 kv_destroy(buf->update_callbacks);
 kv_init(buf->update_callbacks);
 if (!(flags & BLN_DUMMY)) {
   // Tricky: these autocommands may change the buffer list.  They could also
   // split the window with re-using the one empty buffer. This may result in
   // unexpectedly losing the empty buffer.
   bufref_T bufref;
   set_bufref(&bufref, buf);
   if (apply_autocmds(EVENT_BUFNEW, NULL, NULL, false, buf)
       && !bufref_valid(&bufref)) {
     return NULL;
   }
   if ((flags & BLN_LISTED)
       && apply_autocmds(EVENT_BUFADD, NULL, NULL, false, buf)
       && !bufref_valid(&bufref)) {
     return NULL;
   }
   if (aborting()) {
     // Autocmds may abort script processing.
     return NULL;
   }
 }

 buf->b_prompt_callback.type = kCallbackNone;
 buf->b_prompt_interrupt.type = kCallbackNone;
 buf->b_prompt_text = NULL;
 buf->b_prompt_start = (fmark_T)INIT_FMARK;
 buf->b_prompt_start.mark.col = 2;  // default prompt is "% "

 return buf;
}

/// Return true if the current buffer is empty, unnamed, unmodified and used in
/// only one window. That means it can be reused.
bool curbuf_reusable(void)
{
 return (curbuf != NULL
         && curbuf->b_ffname == NULL
         && curbuf->b_nwindows <= 1
         && !curbuf->terminal
         && (curbuf->b_ml.ml_mfp == NULL || buf_is_empty(curbuf))
         && !bt_quickfix(curbuf)
         && !curbufIsChanged());
}

/// Free the memory for the options of a buffer.
/// If "free_p_ff" is true also free 'fileformat', 'buftype' and
/// 'fileencoding'.
void free_buf_options(buf_T *buf, bool free_p_ff)
{
 if (free_p_ff) {
   clear_string_option(&buf->b_p_fenc);
   clear_string_option(&buf->b_p_ff);
   clear_string_option(&buf->b_p_bh);
   clear_string_option(&buf->b_p_bt);
 }
 clear_string_option(&buf->b_p_def);
 clear_string_option(&buf->b_p_inc);
 clear_string_option(&buf->b_p_inex);
 clear_string_option(&buf->b_p_inde);
 clear_string_option(&buf->b_p_indk);
 clear_string_option(&buf->b_p_fp);
 clear_string_option(&buf->b_p_fex);
 clear_string_option(&buf->b_p_kp);
 clear_string_option(&buf->b_p_mps);
 clear_string_option(&buf->b_p_fo);
 clear_string_option(&buf->b_p_flp);
 clear_string_option(&buf->b_p_isk);
 clear_string_option(&buf->b_p_vsts);
 XFREE_CLEAR(buf->b_p_vsts_nopaste);
 XFREE_CLEAR(buf->b_p_vsts_array);
 clear_string_option(&buf->b_p_vts);
 XFREE_CLEAR(buf->b_p_vts_array);
 clear_string_option(&buf->b_p_keymap);
 keymap_ga_clear(&buf->b_kmap_ga);
 ga_clear(&buf->b_kmap_ga);
 clear_string_option(&buf->b_p_com);
 clear_string_option(&buf->b_p_cms);
 clear_string_option(&buf->b_p_nf);
 clear_string_option(&buf->b_p_syn);
 clear_string_option(&buf->b_s.b_syn_isk);
 clear_string_option(&buf->b_s.b_p_spc);
 clear_string_option(&buf->b_s.b_p_spf);
 vim_regfree(buf->b_s.b_cap_prog);
 buf->b_s.b_cap_prog = NULL;
 clear_string_option(&buf->b_s.b_p_spl);
 clear_string_option(&buf->b_s.b_p_spo);
 clear_string_option(&buf->b_p_sua);
 clear_string_option(&buf->b_p_ft);
 clear_string_option(&buf->b_p_cink);
 clear_string_option(&buf->b_p_cino);
 clear_string_option(&buf->b_p_lop);
 clear_string_option(&buf->b_p_cinsd);
 clear_string_option(&buf->b_p_cinw);
 clear_string_option(&buf->b_p_cot);
 clear_string_option(&buf->b_p_cpt);
 clear_string_option(&buf->b_p_cfu);
 callback_free(&buf->b_cfu_cb);
 clear_string_option(&buf->b_p_ofu);
 callback_free(&buf->b_ofu_cb);
 clear_string_option(&buf->b_p_tsrfu);
 callback_free(&buf->b_tsrfu_cb);
 clear_cpt_callbacks(&buf->b_p_cpt_cb, buf->b_p_cpt_count);
 buf->b_p_cpt_count = 0;
 clear_string_option(&buf->b_p_gefm);
 clear_string_option(&buf->b_p_gp);
 clear_string_option(&buf->b_p_mp);
 clear_string_option(&buf->b_p_efm);
 clear_string_option(&buf->b_p_ep);
 clear_string_option(&buf->b_p_path);
 clear_string_option(&buf->b_p_tags);
 clear_string_option(&buf->b_p_tc);
 clear_string_option(&buf->b_p_tfu);
 callback_free(&buf->b_tfu_cb);
 clear_string_option(&buf->b_p_ffu);
 callback_free(&buf->b_ffu_cb);
 clear_string_option(&buf->b_p_dict);
 clear_string_option(&buf->b_p_dia);
 clear_string_option(&buf->b_p_tsr);
 clear_string_option(&buf->b_p_qe);
 buf->b_p_ac = -1;
 buf->b_p_ar = -1;
 buf->b_p_fs = -1;
 buf->b_p_ul = NO_LOCAL_UNDOLEVEL;
 clear_string_option(&buf->b_p_lw);
 clear_string_option(&buf->b_p_bkc);
 clear_string_option(&buf->b_p_menc);
}

/// Get alternate file "n".
/// Set linenr to "lnum" or altfpos.lnum if "lnum" == 0.
/// Also set cursor column to altfpos.col if 'startofline' is not set.
/// if (options & GETF_SETMARK) call setpcmark()
/// if (options & GETF_ALT) we are jumping to an alternate file.
/// if (options & GETF_SWITCH) respect 'switchbuf' settings when jumping
///
/// Return FAIL for failure, OK for success.
int buflist_getfile(int n, linenr_T lnum, int options, int forceit)
{
 win_T *wp = NULL;
 fmark_T *fm = NULL;

 buf_T *buf = buflist_findnr(n);
 if (buf == NULL) {
   if ((options & GETF_ALT) && n == 0) {
     emsg(_(e_noalt));
   } else {
     semsg(_(e_buffer_nr_not_found), n);
   }
   return FAIL;
 }

 // if alternate file is the current buffer, nothing to do
 if (buf == curbuf) {
   return OK;
 }

 if (text_or_buf_locked()) {
   return FAIL;
 }

 colnr_T col;
 bool restore_view = false;
 // altfpos may be changed by getfile(), get it now
 if (lnum == 0) {
   fm = buflist_findfmark(buf);
   lnum = fm->mark.lnum;
   col = fm->mark.col;
   restore_view = true;
 } else {
   col = 0;
 }

 if (options & GETF_SWITCH) {
   // If 'switchbuf' is set jump to the window containing "buf".
   wp = swbuf_goto_win_with_buf(buf);

   // If 'switchbuf' contains "split", "vsplit" or "newtab" and the
   // current buffer isn't empty: open new tab or window
   if (wp == NULL && (swb_flags & (kOptSwbFlagVsplit | kOptSwbFlagSplit | kOptSwbFlagNewtab))
       && !buf_is_empty(curbuf)) {
     if (swb_flags & kOptSwbFlagNewtab) {
       tabpage_new();
     } else if (win_split(0, (swb_flags & kOptSwbFlagVsplit) ? WSP_VERT : 0)
                == FAIL) {
       return FAIL;
     }
     RESET_BINDING(curwin);
   }
 }

 RedrawingDisabled++;
 if (GETFILE_SUCCESS(getfile(buf->b_fnum, NULL, NULL,
                             (options & GETF_SETMARK), lnum, forceit))) {
   RedrawingDisabled--;

   // cursor is at to BOL and w_cursor.lnum is checked due to getfile()
   if (!p_sol && col != 0) {
     curwin->w_cursor.col = col;
     check_cursor_col(curwin);
     curwin->w_cursor.coladd = 0;
     curwin->w_set_curswant = true;
   }
   if (jop_flags & kOptJopFlagView && restore_view) {
     mark_view_restore(fm);
   }
   return OK;
 }
 RedrawingDisabled--;
 return FAIL;
}

/// Go to the last known line number for the current buffer.
static void buflist_getfpos(void)
{
 fmark_T *fm = buflist_findfmark(curbuf);
 const pos_T *fpos = &fm->mark;

 curwin->w_cursor.lnum = fpos->lnum;
 check_cursor_lnum(curwin);

 if (p_sol) {
   curwin->w_cursor.col = 0;
 } else {
   curwin->w_cursor.col = fpos->col;
   check_cursor_col(curwin);
   curwin->w_cursor.coladd = 0;
   curwin->w_set_curswant = true;
 }

 if (jop_flags & kOptJopFlagView) {
   mark_view_restore(fm);
 }
}

/// Find file in buffer list by name (it has to be for the current window).
///
/// @return  buffer or NULL if not found
buf_T *buflist_findname_exp(char *fname)
{
 buf_T *buf = NULL;

 // First make the name into a full path name
 char *ffname = FullName_save(fname,
#ifdef UNIX
                              // force expansion, get rid of symbolic links
                              true
#else
                              false
#endif
                              );
 if (ffname != NULL) {
   buf = buflist_findname(ffname);
   xfree(ffname);
 }
 return buf;
}

/// Find file in buffer list by name (it has to be for the current window).
/// "ffname" must have a full path.
/// Skips dummy buffers.
///
/// @return  buffer or NULL if not found
buf_T *buflist_findname(char *ffname)
{
 FileID file_id;
 bool file_id_valid = os_fileid(ffname, &file_id);
 return buflist_findname_file_id(ffname, &file_id, file_id_valid);
}

/// Same as buflist_findname(), but pass the FileID structure to avoid
/// getting it twice for the same file.
///
/// @return  buffer or NULL if not found
static buf_T *buflist_findname_file_id(char *ffname, FileID *file_id, bool file_id_valid)
 FUNC_ATTR_PURE
{
 // Start at the last buffer, expect to find a match sooner.
 FOR_ALL_BUFFERS_BACKWARDS(buf) {
   if ((buf->b_flags & BF_DUMMY) == 0
       && !otherfile_buf(buf, ffname, file_id, file_id_valid)) {
     return buf;
   }
 }
 return NULL;
}

/// Find file in buffer list by a regexp pattern.
///
/// @param pattern_end  pointer to first char after pattern
/// @param unlisted  find unlisted buffers
/// @param diffmode  find diff-mode buffers only
/// @param curtab_only  find buffers in current tab only
///
/// @return  fnum of the found buffer or < 0 for error.
int buflist_findpat(const char *pattern, const char *pattern_end, bool unlisted, bool diffmode,
                   bool curtab_only)
 FUNC_ATTR_NONNULL_ARG(1)
{
 int match = -1;

 if (pattern_end == pattern + 1 && (*pattern == '%' || *pattern == '#')) {
   match = *pattern == '%' ? curbuf->b_fnum : curwin->w_alt_fnum;
   buf_T *found_buf = buflist_findnr(match);
   if (diffmode && !(found_buf && diff_mode_buf(found_buf))) {
     match = -1;
   }
 } else {
   // Try four ways of matching a listed buffer:
   // attempt == 0: without '^' or '$' (at any position)
   // attempt == 1: with '^' at start (only at position 0)
   // attempt == 2: with '$' at end (only match at end)
   // attempt == 3: with '^' at start and '$' at end (only full match)
   // Repeat this for finding an unlisted buffer if there was no matching
   // listed buffer.

   char *pat = file_pat_to_reg_pat(pattern, pattern_end, NULL, false);
   if (pat == NULL) {
     return -1;
   }
   char *patend = pat + strlen(pat) - 1;
   bool toggledollar = (patend > pat && *patend == '$');

   // First try finding a listed buffer.  If not found and "unlisted"
   // is true, try finding an unlisted buffer.

   int find_listed = true;
   while (true) {
     for (int attempt = 0; attempt <= 3; attempt++) {
       // may add '^' and '$'
       if (toggledollar) {
         *patend = (attempt < 2) ? NUL : '$';           // add/remove '$'
       }
       char *p = pat;
       if (*p == '^' && !(attempt & 1)) {               // add/remove '^'
         p++;
       }

       regmatch_T regmatch;
       regmatch.regprog = vim_regcomp(p, magic_isset() ? RE_MAGIC : 0);

       FOR_ALL_BUFFERS_BACKWARDS(buf) {
         if (regmatch.regprog == NULL) {
           // invalid pattern, possibly after switching engine
           xfree(pat);
           return -1;
         }
         if (buf->b_p_bl == find_listed
             && (!diffmode || diff_mode_buf(buf))
             && buflist_match(&regmatch, buf, false) != NULL) {
           if (curtab_only) {
             // Ignore the match if the buffer is not open in
             // the current tab.
             bool found_window = false;
             FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
               if (wp->w_buffer == buf) {
                 found_window = true;
                 break;
               }
             }
             if (!found_window) {
               continue;
             }
           }
           if (match >= 0) {                   // already found a match
             match = -2;
             break;
           }
           match = buf->b_fnum;                // remember first match
         }
       }

       vim_regfree(regmatch.regprog);
       if (match >= 0) {                       // found one match
         break;
       }
     }

     // Only search for unlisted buffers if there was no match with
     // a listed buffer.
     if (!unlisted || !find_listed || match != -1) {
       break;
     }
     find_listed = false;
   }

   xfree(pat);
 }

 if (match == -2) {
   semsg(_("E93: More than one match for %s"), pattern);
 } else if (match < 0) {
   semsg(_("E94: No matching buffer for %s"), pattern);
 }
 return match;
}

typedef struct {
 buf_T *buf;
 char *match;
} bufmatch_T;

/// Compare functions for qsort() below, that compares b_last_used.
static int buf_time_compare(const void *s1, const void *s2)
{
 buf_T *buf1 = *(buf_T **)s1;
 buf_T *buf2 = *(buf_T **)s2;

 if (buf1->b_last_used == buf2->b_last_used) {
   return 0;
 }
 return buf1->b_last_used > buf2->b_last_used ? -1 : 1;
}

/// Find all buffer names that match.
/// For command line expansion of ":buf" and ":sbuf".
///
/// @return  OK if matches found, FAIL otherwise.
int ExpandBufnames(char *pat, int *num_file, char ***file, int options)
{
 bufmatch_T *matches = NULL;
 bool to_free = false;

 *num_file = 0;                    // return values in case of FAIL
 *file = NULL;

 if ((options & BUF_DIFF_FILTER) && !curwin->w_p_diff) {
   return FAIL;
 }

 const bool fuzzy = cmdline_fuzzy_complete(pat);

 char *patc = NULL;
 fuzmatch_str_T *fuzmatch = NULL;
 regmatch_T regmatch;

 // Make a copy of "pat" and change "^" to "\(^\|[\/]\)" (if doing regular
 // expression matching)
 if (!fuzzy) {
   if (*pat == '^' && pat[1] != NUL) {
     patc = xstrdup(pat + 1);
     to_free = true;
   } else if (*pat == '^') {
     patc = "";
   } else {
     patc = pat;
   }
   regmatch.regprog = vim_regcomp(patc, RE_MAGIC);
 }

 int count = 0;
 int score = 0;
 // round == 1: Count the matches.
 // round == 2: Build the array to keep the matches.
 for (int round = 1; round <= 2; round++) {
   count = 0;
   FOR_ALL_BUFFERS(buf) {
     if (!buf->b_p_bl) {             // skip unlisted buffers
       continue;
     }
     if (options & BUF_DIFF_FILTER) {
       // Skip buffers not suitable for
       // :diffget or :diffput completion.
       if (buf == curbuf || !diff_mode_buf(buf)) {
         continue;
       }
     }

     char *p = NULL;
     if (!fuzzy) {
       if (regmatch.regprog == NULL) {
         // invalid pattern, possibly after recompiling
         if (to_free) {
           xfree(patc);
         }
         return FAIL;
       }
       p = buflist_match(&regmatch, buf, p_wic);
     } else {
       p = NULL;
       // first try matching with the short file name
       if ((score = fuzzy_match_str(buf->b_sfname, pat)) != FUZZY_SCORE_NONE) {
         p = buf->b_sfname;
       }
       if (p == NULL) {
         // next try matching with the full path file name
         if ((score = fuzzy_match_str(buf->b_ffname, pat)) != FUZZY_SCORE_NONE) {
           p = buf->b_ffname;
         }
       }
     }

     if (p == NULL) {
       continue;
     }

     if (round == 1) {
       count++;
       continue;
     }

     if (options & WILD_HOME_REPLACE) {
       p = home_replace_save(buf, p);
     } else {
       p = xstrdup(p);
     }

     if (!fuzzy) {
       if (matches != NULL) {
         matches[count].buf = buf;
         matches[count].match = p;
         count++;
       } else {
         (*file)[count++] = p;
       }
     } else {
       fuzmatch[count].idx = count;
       fuzmatch[count].str = p;
       fuzmatch[count].score = score;
       count++;
     }
   }
   if (count == 0) {         // no match found, break here
     break;
   }
   if (round == 1) {
     if (!fuzzy) {
       *file = xmalloc((size_t)count * sizeof(**file));
       if (options & WILD_BUFLASTUSED) {
         matches = xmalloc((size_t)count * sizeof(*matches));
       }
     } else {
       fuzmatch = xmalloc((size_t)count * sizeof(fuzmatch_str_T));
     }
   }
 }

 if (!fuzzy) {
   vim_regfree(regmatch.regprog);
   if (to_free) {
     xfree(patc);
   }
 }

 if (!fuzzy) {
   if (matches != NULL) {
     if (count > 1) {
       qsort(matches, (size_t)count, sizeof(bufmatch_T), buf_time_compare);
     }

     // if the current buffer is first in the list, place it at the end
     if (matches[0].buf == curbuf) {
       for (int i = 1; i < count; i++) {
         (*file)[i - 1] = matches[i].match;
       }
       (*file)[count - 1] = matches[0].match;
     } else {
       for (int i = 0; i < count; i++) {
         (*file)[i] = matches[i].match;
       }
     }
     xfree(matches);
   }
 } else {
   fuzzymatches_to_strmatches(fuzmatch, file, count, false);
 }

 *num_file = count;
 return count == 0 ? FAIL : OK;
}

/// Check for a match on the file name for buffer "buf" with regprog "prog".
/// Note that rmp->regprog may become NULL when switching regexp engine.
///
/// @param ignore_case  When true, ignore case. Use 'fic' otherwise.
static char *buflist_match(regmatch_T *rmp, buf_T *buf, bool ignore_case)
{
 // First try the short file name, then the long file name.
 char *match = fname_match(rmp, buf->b_sfname, ignore_case);
 if (match == NULL && rmp->regprog != NULL) {
   match = fname_match(rmp, buf->b_ffname, ignore_case);
 }
 return match;
}

/// Try matching the regexp in "rmp->regprog" with file name "name".
/// Note that rmp->regprog may become NULL when switching regexp engine.
///
/// @param ignore_case  When true, ignore case. Use 'fileignorecase' otherwise.
///
/// @return  "name" when there is a match, NULL when not.
static char *fname_match(regmatch_T *rmp, char *name, bool ignore_case)
{
 char *match = NULL;

 // extra check for valid arguments
 if (name == NULL || rmp->regprog == NULL) {
   return NULL;
 }

 // Ignore case when 'fileignorecase' or the argument is set.
 rmp->rm_ic = p_fic || ignore_case;
 if (vim_regexec(rmp, name, 0)) {
   match = name;
 } else if (rmp->regprog != NULL) {
   // Replace $(HOME) with '~' and try matching again.
   char *p = home_replace_save(NULL, name);
   if (vim_regexec(rmp, p, 0)) {
     match = name;
   }
   xfree(p);
 }

 return match;
}

/// Find a file in the buffer list by buffer number.
buf_T *buflist_findnr(int nr)
{
 if (nr == 0) {
   nr = curwin->w_alt_fnum;
 }

 return handle_get_buffer((handle_T)nr);
}

/// Get name of file 'n' in the buffer list.
/// When the file has no name an empty string is returned.
/// home_replace() is used to shorten the file name (used for marks).
///
/// @param helptail  for help buffers return tail only
///
/// @return  a pointer to allocated memory, of NULL when failed.
char *buflist_nr2name(int n, int fullname, int helptail)
{
 buf_T *buf = buflist_findnr(n);
 if (buf == NULL) {
   return NULL;
 }
 return home_replace_save(helptail ? buf : NULL,
                          fullname ? buf->b_ffname : buf->b_fname);
}

/// Set the line and column numbers for the given buffer and window
///
/// @param[in,out]  buf           Buffer for which line and column are set.
/// @param[in,out]  win           Window for which line and column are set.
///                               May be NULL when using :badd.
/// @param[in]      lnum          Line number to be set. If it is zero then only
///                               options are touched.
/// @param[in]      col           Column number to be set.
/// @param[in]      copy_options  If true save the local window option values.
void buflist_setfpos(buf_T *const buf, win_T *const win, linenr_T lnum, colnr_T col,
                    bool copy_options)
 FUNC_ATTR_NONNULL_ARG(1)
{
 WinInfo *wip;

 size_t i;
 for (i = 0; i < kv_size(buf->b_wininfo); i++) {
   wip = kv_A(buf->b_wininfo, i);
   if (wip->wi_win == win) {
     break;
   }
 }

 if (i == kv_size(buf->b_wininfo)) {
   // allocate a new entry
   wip = xcalloc(1, sizeof(WinInfo));
   wip->wi_win = win;
   if (lnum == 0) {            // set lnum even when it's 0
     lnum = 1;
   }
 } else {
   // remove the entry from the list
   kv_shift(buf->b_wininfo, i, 1);
   if (copy_options && wip->wi_optset) {
     clear_winopt(&wip->wi_opt);
     deleteFoldRecurse(buf, &wip->wi_folds);
   }
 }
 if (lnum != 0) {
   wip->wi_mark.mark.lnum = lnum;
   wip->wi_mark.mark.col = col;
   if (win != NULL) {
     wip->wi_mark.view = mark_view_make(win->w_topline, wip->wi_mark.mark);
   }
 }
 if (win != NULL) {
   wip->wi_changelistidx = win->w_changelistidx;
 }
 if (copy_options && win != NULL) {
   // Save the window-specific option values.
   copy_winopt(&win->w_onebuf_opt, &wip->wi_opt);
   wip->wi_fold_manual = win->w_fold_manual;
   cloneFoldGrowArray(&win->w_folds, &wip->wi_folds);
   wip->wi_optset = true;
 }

 // insert the entry in front of the list
 kv_pushp(buf->b_wininfo);
 memmove(&kv_A(buf->b_wininfo, 1), &kv_A(buf->b_wininfo, 0),
         (kv_size(buf->b_wininfo) - 1) * sizeof(kv_A(buf->b_wininfo, 0)));
 kv_A(buf->b_wininfo, 0) = wip;
}

/// Check that "wip" has 'diff' set and the diff is only for another tab page.
/// That's because a diff is local to a tab page.
static bool wininfo_other_tab_diff(WinInfo *wip)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
{
 if (!wip->wi_opt.wo_diff) {
   return false;
 }

 FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
   // return false when it's a window in the current tab page, thus
   // the buffer was in diff mode here
   if (wip->wi_win == wp) {
     return false;
   }
 }
 return true;
}

/// Find info for the current window in buffer "buf".
/// If not found, return the info for the most recently used window.
///
/// @param need_options      when true, skip entries where wi_optset is false.
/// @param skip_diff_buffer  when true, avoid windows with 'diff' set that is in another tab page.
///
/// @return  NULL when there isn't any info.
static WinInfo *find_wininfo(buf_T *buf, bool need_options, bool skip_diff_buffer)
 FUNC_ATTR_NONNULL_ALL FUNC_ATTR_PURE
{
 for (size_t i = 0; i < kv_size(buf->b_wininfo); i++) {
   WinInfo *wip = kv_A(buf->b_wininfo, i);
   if (wip->wi_win == curwin
       && (!skip_diff_buffer || !wininfo_other_tab_diff(wip))
       && (!need_options || wip->wi_optset)) {
     return wip;
   }
 }

 // If no wininfo for curwin, use the first in the list (that doesn't have
 // 'diff' set and is in another tab page).
 // If "need_options" is true skip entries that don't have options set,
 // unless the window is editing "buf", so we can copy from the window
 // itself.
 if (skip_diff_buffer) {
   for (size_t i = 0; i < kv_size(buf->b_wininfo); i++) {
     WinInfo *wip = kv_A(buf->b_wininfo, i);
     if (!wininfo_other_tab_diff(wip)
         && (!need_options
             || wip->wi_optset
             || (wip->wi_win != NULL
                 && wip->wi_win->w_buffer == buf))) {
       return wip;
     }
   }
 } else if (kv_size(buf->b_wininfo)) {
   return kv_A(buf->b_wininfo, 0);
 }
 return NULL;
}

/// Reset the local window options to the values last used in this window.
/// If the buffer wasn't used in this window before, use the values from
/// the most recently used window.  If the values were never set, use the
/// global values for the window.
void get_winopts(buf_T *buf)
{
 clear_winopt(&curwin->w_onebuf_opt);
 clearFolding(curwin);

 WinInfo *const wip = find_wininfo(buf, true, true);
 if (wip != NULL && wip->wi_win != curwin && wip->wi_win != NULL
     && wip->wi_win->w_buffer == buf) {
   win_T *wp = wip->wi_win;
   copy_winopt(&wp->w_onebuf_opt, &curwin->w_onebuf_opt);
   curwin->w_fold_manual = wp->w_fold_manual;
   curwin->w_foldinvalid = true;
   cloneFoldGrowArray(&wp->w_folds, &curwin->w_folds);
 } else if (wip != NULL && wip->wi_optset) {
   copy_winopt(&wip->wi_opt, &curwin->w_onebuf_opt);
   curwin->w_fold_manual = wip->wi_fold_manual;
   curwin->w_foldinvalid = true;
   cloneFoldGrowArray(&wip->wi_folds, &curwin->w_folds);
 } else {
   copy_winopt(&curwin->w_allbuf_opt, &curwin->w_onebuf_opt);
 }
 if (wip != NULL) {
   curwin->w_changelistidx = wip->wi_changelistidx;
 }

 if (curwin->w_config.style == kWinStyleMinimal) {
   didset_window_options(curwin, false);
   win_set_minimal_style(curwin);
 }

 // Set 'foldlevel' to 'foldlevelstart' if it's not negative.
 if (p_fdls >= 0) {
   curwin->w_p_fdl = p_fdls;
 }
 didset_window_options(curwin, false);
}

/// Find the mark for the buffer 'buf' for the current window.
///
/// @return  a pointer to no_position if no position is found.
fmark_T *buflist_findfmark(buf_T *buf)
 FUNC_ATTR_PURE
{
 static fmark_T no_position = { { 1, 0, 0 }, 0, 0, INIT_FMARKV, NULL };

 WinInfo *const wip = find_wininfo(buf, false, false);
 return (wip == NULL) ? &no_position : &(wip->wi_mark);
}

/// Find the lnum for the buffer 'buf' for the current window.
linenr_T buflist_findlnum(buf_T *buf)
 FUNC_ATTR_PURE
{
 return buflist_findfmark(buf)->mark.lnum;
}

/// List all known file names (for :files and :buffers command).
void buflist_list(exarg_T *eap)
{
 buf_T *buf = firstbuf;

 garray_T buflist;
 buf_T **buflist_data = NULL;

 msg_ext_set_kind("list_cmd");
 if (vim_strchr(eap->arg, 't')) {
   ga_init(&buflist, sizeof(buf_T *), 50);
   for (buf = firstbuf; buf != NULL; buf = buf->b_next) {
     ga_grow(&buflist, 1);
     ((buf_T **)buflist.ga_data)[buflist.ga_len++] = buf;
   }

   qsort(buflist.ga_data, (size_t)buflist.ga_len,
         sizeof(buf_T *), buf_time_compare);

   buflist_data = (buf_T **)buflist.ga_data;
   buf = *buflist_data;
 }
 buf_T **p = buflist_data;

 for (;
      buf != NULL && !got_int;
      buf = buflist_data != NULL
            ? (++p < buflist_data + buflist.ga_len ? *p : NULL) : buf->b_next) {
   const bool is_terminal = buf->terminal;
   const bool job_running = buf->terminal && terminal_running(buf->terminal);

   // skip unspecified buffers
   if ((!buf->b_p_bl && !eap->forceit && !vim_strchr(eap->arg, 'u'))
       || (vim_strchr(eap->arg, 'u') && buf->b_p_bl)
       || (vim_strchr(eap->arg, '+')
           && ((buf->b_flags & BF_READERR) || !bufIsChanged(buf)))
       || (vim_strchr(eap->arg, 'a')
           && (buf->b_ml.ml_mfp == NULL || buf->b_nwindows == 0))
       || (vim_strchr(eap->arg, 'h')
           && (buf->b_ml.ml_mfp == NULL || buf->b_nwindows != 0))
       || (vim_strchr(eap->arg, 'R') && (!is_terminal || !job_running))
       || (vim_strchr(eap->arg, 'F') && (!is_terminal || job_running))
       || (vim_strchr(eap->arg, '-') && buf->b_p_ma)
       || (vim_strchr(eap->arg, '=') && !buf->b_p_ro)
       || (vim_strchr(eap->arg, 'x') && !(buf->b_flags & BF_READERR))
       || (vim_strchr(eap->arg, '%') && buf != curbuf)
       || (vim_strchr(eap->arg, '#')
           && (buf == curbuf || curwin->w_alt_fnum != buf->b_fnum))) {
     continue;
   }
   char *name = buf_spname(buf);
   if (name != NULL) {
     xstrlcpy(NameBuff, name, MAXPATHL);
   } else {
     home_replace(buf, buf->b_fname, NameBuff, MAXPATHL, true);
   }

   if (message_filtered(NameBuff)) {
     continue;
   }

   const int changed_char = (buf->b_flags & BF_READERR)
                            ? 'x'
                            : (bufIsChanged(buf) ? '+' : ' ');
   int ro_char = !MODIFIABLE(buf) ? '-' : (buf->b_p_ro ? '=' : ' ');
   if (buf->terminal) {
     ro_char = terminal_running(buf->terminal) ? 'R' : 'F';
   }

   if (!ui_has(kUIMessages) || msg_col > 0) {
     msg_putchar('\n');
   }
   int len = (int)vim_snprintf_safelen(IObuff, IOSIZE - 20, "%3d%c%c%c%c%c \"%s\"",
                                       buf->b_fnum,
                                       buf->b_p_bl ? ' ' : 'u',
                                       buf == curbuf ? '%'
                                                     : (curwin->w_alt_fnum
                                                        == buf->b_fnum ? '#' : ' '),
                                       buf->b_ml.ml_mfp == NULL ? ' '
                                                                : (buf->b_nwindows
                                                                   == 0 ? 'h' : 'a'),
                                       ro_char,
                                       changed_char,
                                       NameBuff);

   len = MIN(len, IOSIZE - 20);

   // put "line 999" in column 40 or after the file name
   int i = 40 - vim_strsize(IObuff);
   do {
     IObuff[len++] = ' ';
   } while (--i > 0 && len < IOSIZE - 18);
   if (vim_strchr(eap->arg, 't') && buf->b_last_used) {
     undo_fmt_time(IObuff + len, (size_t)(IOSIZE - len), buf->b_last_used);
   } else {
     vim_snprintf(IObuff + len, (size_t)(IOSIZE - len), _("line %" PRId64),
                  buf == curbuf ? (int64_t)curwin->w_cursor.lnum : (int64_t)buflist_findlnum(buf));
   }

   msg_outtrans(IObuff, 0, false);
   line_breakcheck();
 }

 if (buflist_data) {
   ga_clear(&buflist);
 }
}

/// Get file name and line number for file 'fnum'.
/// Used by DoOneCmd() for translating '%' and '#'.
/// Used by insert_reg() and cmdline_paste() for '#' register.
///
/// @return  FAIL if not found, OK for success.
int buflist_name_nr(int fnum, char **fname, linenr_T *lnum)
{
 buf_T *buf = buflist_findnr(fnum);
 if (buf == NULL || buf->b_fname == NULL) {
   return FAIL;
 }

 *fname = buf->b_fname;
 *lnum = buflist_findlnum(buf);

 return OK;
}

/// Set the file name for "buf" to "ffname_arg", short file name to
/// "sfname_arg".
/// The file name with the full path is also remembered, for when :cd is used.
///
/// @param message  give message when buffer already exists
///
/// @return  FAIL for failure (file name already in use by other buffer) OK otherwise.
int setfname(buf_T *buf, char *ffname_arg, char *sfname_arg, bool message)
{
 char *ffname = ffname_arg;
 char *sfname = sfname_arg;
 buf_T *obuf = NULL;
 FileID file_id;
 bool file_id_valid = false;

 if (ffname == NULL || *ffname == NUL) {
   // Removing the name.
   if (buf->b_sfname != buf->b_ffname) {
     XFREE_CLEAR(buf->b_sfname);
   } else {
     buf->b_sfname = NULL;
   }
   XFREE_CLEAR(buf->b_ffname);
 } else {
   fname_expand(buf, &ffname, &sfname);    // will allocate ffname
   if (ffname == NULL) {                   // out of memory
     return FAIL;
   }

   // If the file name is already used in another buffer:
   // - if the buffer is loaded, fail
   // - if the buffer is not loaded, delete it from the list
   file_id_valid = os_fileid(ffname, &file_id);
   if (!(buf->b_flags & BF_DUMMY)) {
     obuf = buflist_findname_file_id(ffname, &file_id, file_id_valid);
   }
   if (obuf != NULL && obuf != buf) {
     bool in_use = false;

     // during startup a window may use a buffer that is not loaded yet
     FOR_ALL_TAB_WINDOWS(tab, win) {
       if (win->w_buffer == obuf) {
         in_use = true;
       }
     }

     // it's loaded or used in a window, fail
     if (obuf->b_ml.ml_mfp != NULL || in_use) {
       if (message) {
         emsg(_("E95: Buffer with this name already exists"));
       }
       xfree(ffname);
       return FAIL;
     }
     // delete from the list
     close_buffer(NULL, obuf, DOBUF_WIPE, false, false);
   }
   sfname = xstrdup(sfname);
#ifdef CASE_INSENSITIVE_FILENAME
   path_fix_case(sfname);            // set correct case for short file name
#endif
   if (buf->b_sfname != buf->b_ffname) {
     xfree(buf->b_sfname);
   }
   xfree(buf->b_ffname);
   buf->b_ffname = ffname;
   buf->b_sfname = sfname;
 }
 buf->b_fname = buf->b_sfname;
 if (!file_id_valid) {
   buf->file_id_valid = false;
 } else {
   buf->file_id_valid = true;
   buf->file_id = file_id;
 }

 buf_name_changed(buf);
 return OK;
}

/// Crude way of changing the name of a buffer.  Use with care!
/// The name should be relative to the current directory.
void buf_set_name(int fnum, char *name)
{
 buf_T *buf = buflist_findnr(fnum);
 if (buf == NULL) {
   return;
 }

 if (buf->b_sfname != buf->b_ffname) {
   xfree(buf->b_sfname);
 }
 xfree(buf->b_ffname);
 buf->b_ffname = xstrdup(name);
 buf->b_sfname = NULL;
 // Allocate ffname and expand into full path.  Also resolves .lnk
 // files on Win32.
 fname_expand(buf, &buf->b_ffname, &buf->b_sfname);
 buf->b_fname = buf->b_sfname;
}

/// Take care of what needs to be done when the name of buffer "buf" has changed.
void buf_name_changed(buf_T *buf)
{
 // If the file name changed, also change the name of the swapfile
 if (buf->b_ml.ml_mfp != NULL) {
   ml_setname(buf);
 }

 if (curwin->w_buffer == buf) {
   check_arg_idx(curwin);      // check file name for arg list
 }
 maketitle();                  // set window title
 status_redraw_all();          // status lines need to be redrawn
 fmarks_check_names(buf);      // check named file marks
 ml_timestamp(buf);            // reset timestamp
}

/// Set alternate file name for current window
///
/// Used by do_one_cmd(), do_write() and do_ecmd().
///
/// @return  the buffer.
buf_T *setaltfname(char *ffname, char *sfname, linenr_T lnum)
{
 // Create a buffer.  'buflisted' is not set if it's a new buffer
 buf_T *buf = buflist_new(ffname, sfname, lnum, 0);
 if (buf != NULL && (cmdmod.cmod_flags & CMOD_KEEPALT) == 0) {
   curwin->w_alt_fnum = buf->b_fnum;
 }
 return buf;
}

/// Get alternate file name for current window.
/// Return NULL if there isn't any, and give error message if requested.
///
/// @param errmsg  give error message
char *getaltfname(bool errmsg)
{
 char *fname;
 linenr_T dummy;

 if (buflist_name_nr(0, &fname, &dummy) == FAIL) {
   if (errmsg) {
     emsg(_(e_noalt));
   }
   return NULL;
 }
 return fname;
}

/// Add a file name to the buflist and return its number.
/// Uses same flags as buflist_new(), except BLN_DUMMY.
///
/// Used by qf_init(), main() and doarglist()
int buflist_add(char *fname, int flags)
{
 buf_T *buf = buflist_new(fname, NULL, 0, flags);
 if (buf != NULL) {
   return buf->b_fnum;
 }
 return 0;
}

#if defined(BACKSLASH_IN_FILENAME)
/// Adjust slashes in file names.  Called after 'shellslash' was set.
void buflist_slash_adjust(void)
{
 FOR_ALL_BUFFERS(bp) {
   if (bp->b_ffname != NULL) {
     slash_adjust(bp->b_ffname);
   }
   if (bp->b_sfname != NULL) {
     slash_adjust(bp->b_sfname);
   }
 }
}

#endif

/// Set alternate cursor position for the current buffer and window "win".
/// Also save the local window option values.
void buflist_altfpos(win_T *win)
{
 buflist_setfpos(curbuf, win, win->w_cursor.lnum, win->w_cursor.col,
                 win->w_config.style != kWinStyleMinimal);
}

/// Check that "ffname" is not the same file as current file.
/// Fname must have a full path (expanded by path_to_absolute()).
///
/// @param  ffname  full path name to check
bool otherfile(char *ffname)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
{
 return otherfile_buf(curbuf, ffname, NULL, false);
}

/// Check that "ffname" is not the same file as the file loaded in "buf".
/// Fname must have a full path (expanded by path_to_absolute()).
///
/// @param  buf            buffer to check
/// @param  ffname         full path name to check
/// @param  file_id_p      information about the file at "ffname".
/// @param  file_id_valid  whether a valid "file_id_p" was passed in.
static bool otherfile_buf(buf_T *buf, char *ffname, FileID *file_id_p, bool file_id_valid)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 // no name is different
 if (ffname == NULL || *ffname == NUL || buf->b_ffname == NULL) {
   return true;
 }
 if (path_fnamecmp(ffname, buf->b_ffname) == 0) {
   return false;
 }
 {
   FileID file_id;
   // If no struct stat given, get it now
   if (file_id_p == NULL) {
     file_id_p = &file_id;
     file_id_valid = os_fileid(ffname, file_id_p);
   }
   if (!file_id_valid) {
     // file_id not valid, assume files are different.
     return true;
   }
   // Use dev/ino to check if the files are the same, even when the names
   // are different (possible with links).  Still need to compare the
   // name above, for when the file doesn't exist yet.
   // Problem: The dev/ino changes when a file is deleted (and created
   // again) and remains the same when renamed/moved.  We don't want to
   // stat() each buffer each time, that would be too slow.  Get the
   // dev/ino again when they appear to match, but not when they appear
   // to be different: Could skip a buffer when it's actually the same
   // file.
   if (buf_same_file_id(buf, file_id_p)) {
     buf_set_file_id(buf);
     if (buf_same_file_id(buf, file_id_p)) {
       return false;
     }
   }
 }
 return true;
}

/// Set file_id for a buffer.
/// Must always be called when b_fname is changed!
void buf_set_file_id(buf_T *buf)
{
 FileID file_id;
 if (buf->b_fname != NULL
     && os_fileid(buf->b_fname, &file_id)) {
   buf->file_id_valid = true;
   buf->file_id = file_id;
 } else {
   buf->file_id_valid = false;
 }
}

/// Check that file_id in buffer "buf" matches with "file_id".
///
/// @param  buf      buffer
/// @param  file_id  file id
static bool buf_same_file_id(buf_T *buf, FileID *file_id)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
{
 return buf->file_id_valid && os_fileid_equal(&(buf->file_id), file_id);
}

/// Print info about the current buffer.
///
/// @param fullname  when non-zero print full path
void fileinfo(int fullname, int shorthelp, bool dont_truncate)
{
 char *buffer = xmalloc(IOSIZE);
 size_t bufferlen = 0;

 if (fullname > 1) {       // 2 CTRL-G: include buffer number
   bufferlen = vim_snprintf_safelen(buffer, IOSIZE, "buf %d: ", curbuf->b_fnum);
 }

 buffer[bufferlen++] = '"';

 char *name = buf_spname(curbuf);
 if (name != NULL) {
   bufferlen += vim_snprintf_safelen(buffer + bufferlen,
                                     IOSIZE - bufferlen, "%s", name);
 } else {
   name = (!fullname && curbuf->b_fname != NULL) ? curbuf->b_fname : curbuf->b_ffname;
   home_replace(shorthelp ? curbuf : NULL, name, buffer + bufferlen,
                IOSIZE - bufferlen, true);
   bufferlen += strlen(buffer + bufferlen);
 }

 bool dontwrite = bt_dontwrite(curbuf);
 bufferlen += vim_snprintf_safelen(buffer + bufferlen,
                                   IOSIZE - bufferlen,
                                   "\"%s%s%s%s%s%s",
                                   curbufIsChanged()
                                   ? (shortmess(SHM_MOD) ? " [+]" : _(" [Modified]"))
                                   : " ",
                                   (curbuf->b_flags & BF_NOTEDITED) && !dontwrite
                                   ? _("[Not edited]") : "",
                                   (curbuf->b_flags & BF_NEW) && !dontwrite
                                   ? _("[New]") : "",
                                   (curbuf->b_flags & BF_READERR)
                                   ? _("[Read errors]") : "",
                                   curbuf->b_p_ro
                                   ? (shortmess(SHM_RO) ? _("[RO]") : _("[readonly]"))
                                   : "",
                                   (curbufIsChanged()
                                    || (curbuf->b_flags & BF_WRITE_MASK)
                                    || curbuf->b_p_ro)
                                   ? " " : "");

 if (curbuf->b_ml.ml_flags & ML_EMPTY) {
   bufferlen += vim_snprintf_safelen(buffer + bufferlen,
                                     IOSIZE - bufferlen, "%s", _(no_lines_msg));
 } else if (p_ru) {
   // Current line and column are already on the screen -- webb
   bufferlen += vim_snprintf_safelen(buffer + bufferlen,
                                     IOSIZE - bufferlen,
                                     NGETTEXT("%" PRId64 " line --%d%%--",
                                              "%" PRId64 " lines --%d%%--",
                                              curbuf->b_ml.ml_line_count),
                                     (int64_t)curbuf->b_ml.ml_line_count,
                                     calc_percentage(curwin->w_cursor.lnum,
                                                     curbuf->b_ml.ml_line_count));
 } else {
   bufferlen += vim_snprintf_safelen(buffer + bufferlen,
                                     IOSIZE - bufferlen,
                                     _("line %" PRId64 " of %" PRId64 " --%d%%-- col "),
                                     (int64_t)curwin->w_cursor.lnum,
                                     (int64_t)curbuf->b_ml.ml_line_count,
                                     calc_percentage(curwin->w_cursor.lnum,
                                                     curbuf->b_ml.ml_line_count));
   validate_virtcol(curwin);
   bufferlen += (size_t)col_print(buffer + bufferlen, IOSIZE - bufferlen,
                                  curwin->w_cursor.col + 1, curwin->w_virtcol + 1);
 }

 append_arg_number(curwin, buffer + bufferlen, IOSIZE - bufferlen);

 if (dont_truncate) {
   // Temporarily set msg_scroll to avoid the message being truncated.
   // First call msg_start() to get the message in the right place.
   msg_start();
   int n = msg_scroll;
   msg_scroll = true;
   msg(buffer, 0);
   msg_scroll = n;
 } else {
   char *p = msg_trunc(buffer, false, 0);
   if (restart_edit != 0 || (msg_scrolled && !need_wait_return)) {
     // Need to repeat the message after redrawing when:
     // - When restart_edit is set (otherwise there will be a delay
     //   before redrawing).
     // - When the screen was scrolled but there is no wait-return
     //   prompt.
     set_keep_msg(p, 0);
   }
 }

 xfree(buffer);
}

int col_print(char *buf, size_t buflen, int col, int vcol)
{
 if (col == vcol) {
   return (int)vim_snprintf_safelen(buf, buflen, "%d", col);
 }

 return (int)vim_snprintf_safelen(buf, buflen, "%d-%d", col, vcol);
}

static char *lasttitle = NULL;
static char *lasticon = NULL;

/// Put the title name in the title bar and icon of the window.
void maketitle(void)
{
 char *title_str = NULL;
 char *icon_str = NULL;
 char buf[IOSIZE];

 if (!redrawing()) {
   // Postpone updating the title when 'lazyredraw' is set.
   need_maketitle = true;
   return;
 }

 need_maketitle = false;
 if (!p_title && !p_icon && lasttitle == NULL && lasticon == NULL) {
   return;  // nothing to do
 }

 if (p_title) {
   int maxlen = 0;

   if (p_titlelen > 0) {
     maxlen = MAX((int)(p_titlelen * Columns / 100), 10);
   }

   if (*p_titlestring != NUL) {
     if (stl_syntax & STL_IN_TITLE) {
       build_stl_str_hl(curwin, buf, sizeof(buf), p_titlestring,
                        kOptTitlestring, 0, 0, maxlen, NULL, NULL, NULL, NULL);
       title_str = buf;
     } else {
       title_str = p_titlestring;
     }
   } else {
     // Format: "fname + (path) (1 of 2) - Nvim".
     char *default_titlestring = "%t%( %M%)%( (%{expand(\"%:~:h\")})%)%a - Nvim";
     build_stl_str_hl(curwin, buf, sizeof(buf), default_titlestring,
                      kOptTitlestring, 0, 0, maxlen, NULL, NULL, NULL, NULL);
     title_str = buf;
   }
 }
 bool mustset = value_change(title_str, &lasttitle);

 if (p_icon) {
   icon_str = buf;
   if (*p_iconstring != NUL) {
     if (stl_syntax & STL_IN_ICON) {
       build_stl_str_hl(curwin, icon_str, sizeof(buf), p_iconstring,
                        kOptIconstring, 0, 0, 0, NULL, NULL, NULL, NULL);
     } else {
       icon_str = p_iconstring;
     }
   } else {
     char *name = buf_spname(curbuf);
     if (name == NULL) {
       name = path_tail(curbuf->b_ffname);
     }
     // Truncate name at 100 bytes.
     int namelen = (int)strlen(name);
     if (namelen > 100) {
       namelen -= 100;
       namelen += utf_cp_bounds(name, name + namelen).end_off;
       name += namelen;
     }
     STRCPY(buf, name);
     trans_characters(buf, sizeof(buf));
   }
 }

 mustset |= value_change(icon_str, &lasticon);

 if (mustset) {
   resettitle();
 }
}

/// Used for title and icon: Check if "str" differs from "*last".  Set "*last"
/// from "str" if it does by freeing the old value of "*last" and duplicating
/// "str".
///
/// @param          str   desired title string
/// @param[in,out]  last  current title string
///
/// @return  true if resettitle() is to be called.
static bool value_change(char *str, char **last)
 FUNC_ATTR_WARN_UNUSED_RESULT
{
 if ((str == NULL) != (*last == NULL)
     || (str != NULL && *last != NULL && strcmp(str, *last) != 0)) {
   xfree(*last);
   if (str == NULL) {
     *last = NULL;
     resettitle();
   } else {
     *last = xstrdup(str);
     return true;
   }
 }
 return false;
}

/// Set current window title
void resettitle(void)
{
 ui_call_set_icon(cstr_as_string(lasticon));
 ui_call_set_title(cstr_as_string(lasttitle));
}

#if defined(EXITFREE)
void free_titles(void)
{
 xfree(lasttitle);
 xfree(lasticon);
}

#endif

/// Get relative cursor position in window into "buf[]", in the localized
/// percentage form like %99, 99%; using "Top", "Bot" or "All" when appropriate.
int get_rel_pos(win_T *wp, char *buf, int buflen)
{
 // Need at least 3 chars for writing.
 if (buflen < 3) {
   return 0;
 }

 linenr_T above;          // number of lines above window
 linenr_T below;          // number of lines below window

 above = wp->w_topline - 1;
 above += win_get_fill(wp, wp->w_topline) - wp->w_topfill;
 if (wp->w_topline == 1 && wp->w_topfill >= 1) {
   // All buffer lines are displayed and there is an indication
   // of filler lines, that can be considered seeing all lines.
   above = 0;
 }
 below = wp->w_buffer->b_ml.ml_line_count - wp->w_botline + 1;
 if (below <= 0) {
   return (int)vim_snprintf_safelen(buf, (size_t)buflen,
                                    "%s", (above == 0) ? _("All") : _("Bot"));
 }

 if (above <= 0) {
   return (int)vim_snprintf_safelen(buf, (size_t)buflen,
                                    "%s", _("Top"));
 }

 int perc = calc_percentage(above, above + below);
 char tmp[8];
 // localized percentage value
 vim_snprintf(tmp, sizeof(tmp), _("%d%%"), perc);
 return (int)vim_snprintf_safelen(buf, (size_t)buflen, _("%3s"), tmp);
}

/// Append (2 of 8) to "buf[]", if editing more than one file.
///
/// @param          wp        window whose buffers to check
/// @param[in,out]  buf       string buffer to add the text to
/// @param          buflen    length of the string buffer
///
/// @return  the number of characters appended.
int append_arg_number(win_T *wp, char *buf, size_t buflen)
 FUNC_ATTR_NONNULL_ALL
{
 // Nothing to do
 if (ARGCOUNT <= 1) {
   return 0;
 }

 const char *msg = wp->w_arg_idx_invalid ? _(" ((%d) of %d)") : _(" (%d of %d)");

 return (int)vim_snprintf_safelen(buf, buflen, msg, wp->w_arg_idx + 1, ARGCOUNT);
}

/// Make "*ffname" a full file name, set "*sfname" to "*ffname" if not NULL.
/// "*ffname" becomes a pointer to allocated memory (or NULL).
/// When resolving a link both "*sfname" and "*ffname" will point to the same
/// allocated memory.
/// The "*ffname" and "*sfname" pointer values on call will not be freed.
/// Note that the resulting "*ffname" pointer should be considered not allocated.
void fname_expand(buf_T *buf, char **ffname, char **sfname)
{
 if (*ffname == NULL) {  // no file name given, nothing to do
   return;
 }
 if (*sfname == NULL) {  // no short file name given, use ffname
   *sfname = *ffname;
 }
 *ffname = fix_fname((*ffname));     // expand to full path

#ifdef MSWIN
 if (!buf->b_p_bin) {
   // If the file name is a shortcut file, use the file it links to.
   char *rfname = os_resolve_shortcut(*ffname);
   if (rfname != NULL) {
     xfree(*ffname);
     *ffname = rfname;
     *sfname = rfname;
   }
 }
#endif
}

/// @return  true if "buf" is a prompt buffer.
bool bt_prompt(buf_T *buf)
 FUNC_ATTR_PURE
{
 return buf != NULL && buf->b_p_bt[0] == 'p';
}

/// Open a window for a number of buffers.
void ex_buffer_all(exarg_T *eap)
{
 win_T *wpnext;
 int split_ret = OK;
 int open_wins = 0;
 int had_tab = cmdmod.cmod_tab;

 // Maximum number of windows to open.
 linenr_T count = eap->addr_count == 0
                  ? 9999         // make as many windows as possible
                  : eap->line2;  // make as many windows as specified

 // When true also load inactive buffers.
 int all = eap->cmdidx != CMD_unhide && eap->cmdidx != CMD_sunhide;

 // Stop Visual mode, the cursor and "VIsual" may very well be invalid after
 // switching to another buffer.
 reset_VIsual_and_resel();

 setpcmark();

 // Close superfluous windows (two windows for the same buffer).
 // Also close windows that are not full-width.
 if (had_tab > 0) {
   goto_tabpage_tp(first_tabpage, true, true);
 }
 while (true) {
   tabpage_T *tpnext = curtab->tp_next;
   // Try to close floating windows first
   for (win_T *wp = lastwin->w_floating ? lastwin : firstwin; wp != NULL; wp = wpnext) {
     wpnext = wp->w_floating
              ? wp->w_prev->w_floating ? wp->w_prev : firstwin
              : (wp->w_next == NULL || wp->w_next->w_floating) ? NULL : wp->w_next;
     if ((wp->w_buffer->b_nwindows > 1
          || wp->w_floating
          || ((cmdmod.cmod_split & WSP_VERT)
              ? wp->w_height + wp->w_hsep_height + wp->w_status_height < Rows - p_ch
              - tabline_height() - global_stl_height()
              : wp->w_width != Columns)
          || (had_tab > 0 && wp != firstwin))
         && !ONE_WINDOW
         && !(win_locked(curwin) || wp->w_buffer->b_locked > 0)
         && !is_aucmd_win(wp)) {
       if (win_close(wp, false, false) == FAIL) {
         break;
       }
       // Just in case an autocommand does something strange with
       // windows: start all over...
       wpnext = lastwin->w_floating ? lastwin : firstwin;
       tpnext = first_tabpage;
       open_wins = 0;
     } else {
       open_wins++;
     }
   }

   // Without the ":tab" modifier only do the current tab page.
   if (had_tab == 0 || tpnext == NULL) {
     break;
   }
   goto_tabpage_tp(tpnext, true, true);
 }

 // Go through the buffer list.  When a buffer doesn't have a window yet,
 // open one.  Otherwise move the window to the right position.
 // Watch out for autocommands that delete buffers or windows!
 //
 // Don't execute Win/Buf Enter/Leave autocommands here.
 autocmd_no_enter++;
 // lastwin may be aucmd_win
 win_enter(lastwin_nofloating(), false);
 autocmd_no_leave++;
 for (buf_T *buf = firstbuf; buf != NULL && open_wins < count; buf = buf->b_next) {
   // Check if this buffer needs a window
   if ((!all && buf->b_ml.ml_mfp == NULL) || !buf->b_p_bl) {
     continue;
   }

   win_T *wp;
   if (had_tab != 0) {
     // With the ":tab" modifier don't move the window.
     wp = buf->b_nwindows > 0
          ? lastwin  // buffer has a window, skip it
          : NULL;
   } else {
     // Check if this buffer already has a window
     for (wp = firstwin; wp != NULL; wp = wp->w_next) {
       if (!wp->w_floating && wp->w_buffer == buf) {
         break;
       }
     }
     // If the buffer already has a window, move it
     if (wp != NULL) {
       win_move_after(wp, curwin);
     }
   }

   if (wp == NULL && split_ret == OK) {
     bufref_T bufref;
     set_bufref(&bufref, buf);
     // Split the window and put the buffer in it.
     bool p_ea_save = p_ea;
     p_ea = true;                      // use space from all windows
     split_ret = win_split(0, WSP_ROOM | WSP_BELOW);
     open_wins++;
     p_ea = p_ea_save;
     if (split_ret == FAIL) {
       continue;
     }

     // Open the buffer in this window.
     swap_exists_action = SEA_DIALOG;
     set_curbuf(buf, DOBUF_GOTO, !(jop_flags & kOptJopFlagClean));
     if (!bufref_valid(&bufref)) {
       // Autocommands deleted the buffer.
       swap_exists_action = SEA_NONE;
       break;
     }
     if (swap_exists_action == SEA_QUIT) {
       cleanup_T cs;

       // Reset the error/interrupt/exception state here so that
       // aborting() returns false when closing a window.
       enter_cleanup(&cs);

       // User selected Quit at ATTENTION prompt; close this window.
       win_close(curwin, true, false);
       open_wins--;
       swap_exists_action = SEA_NONE;
       swap_exists_did_quit = true;

       // Restore the error/interrupt/exception state if not
       // discarded by a new aborting error, interrupt, or uncaught
       // exception.
       leave_cleanup(&cs);
     } else {
       handle_swap_exists(NULL);
     }
   }

   os_breakcheck();
   if (got_int) {
     vgetc();            // only break the file loading, not the rest
     break;
   }
   // Autocommands deleted the buffer or aborted script processing!!!
   if (aborting()) {
     break;
   }
   // When ":tab" was used open a new tab for a new window repeatedly.
   if (had_tab > 0 && tabpage_index(NULL) <= p_tpm) {
     cmdmod.cmod_tab = 9999;
   }
 }
 autocmd_no_enter--;
 win_enter(firstwin, false);           // back to first window
 autocmd_no_leave--;

 // Close superfluous windows.
 for (win_T *wp = lastwin; open_wins > count;) {
   bool r = (buf_hide(wp->w_buffer) || !bufIsChanged(wp->w_buffer)
             || autowrite(wp->w_buffer, false) == OK) && !is_aucmd_win(wp);
   if (!win_valid(wp)) {
     // BufWrite Autocommands made the window invalid, start over
     wp = lastwin;
   } else if (r) {
     win_close(wp, !buf_hide(wp->w_buffer), false);
     open_wins--;
     wp = lastwin;
   } else {
     wp = wp->w_prev;
     if (wp == NULL) {
       break;
     }
   }
 }
}

/// do_modelines() - process mode lines for the current file
///
/// @param flags
///        OPT_WINONLY      only set options local to window
///        OPT_NOWIN        don't set options local to window
///
/// Returns immediately if the "ml" option isn't set.
void do_modelines(int flags)
{
 linenr_T lnum;
 int nmlines;
 static int entered = 0;

 if (!curbuf->b_p_ml || (nmlines = (int)p_mls) == 0) {
   return;
 }

 // Disallow recursive entry here.  Can happen when executing a modeline
 // triggers an autocommand, which reloads modelines with a ":do".
 if (entered) {
   return;
 }

 entered++;
 for (lnum = 1; curbuf->b_p_ml && lnum <= curbuf->b_ml.ml_line_count
      && lnum <= nmlines; lnum++) {
   if (chk_modeline(lnum, flags) == FAIL) {
     nmlines = 0;
   }
 }

 for (lnum = curbuf->b_ml.ml_line_count; curbuf->b_p_ml && lnum > 0
      && lnum > nmlines && lnum > curbuf->b_ml.ml_line_count - nmlines;
      lnum--) {
   if (chk_modeline(lnum, flags) == FAIL) {
     nmlines = 0;
   }
 }
 entered--;
}

/// chk_modeline() - check a single line for a mode string
/// Return FAIL if an error encountered.
///
/// @param flags  Same as for do_modelines().
static int chk_modeline(linenr_T lnum, int flags)
{
 char *e;
 int retval = OK;
 ESTACK_CHECK_DECLARATION;

 int prev = -1;
 char *s = ml_get(lnum);
 char *line_end = s + ml_get_len(lnum);
 for (; *s != NUL; s++) {
   if (prev == -1 || ascii_isspace(prev)) {
     if ((prev != -1 && strncmp(s, "ex:", 3) == 0)
         || strncmp(s, "vi:", 3) == 0) {
       break;
     }
     // Accept both "vim" and "Vim".
     if ((s[0] == 'v' || s[0] == 'V') && s[1] == 'i' && s[2] == 'm') {
       if (s[3] == '<' || s[3] == '=' || s[3] == '>') {
         e = s + 4;
       } else {
         e = s + 3;
       }
       intmax_t vers;
       if (!try_getdigits(&e, &vers)) {
         continue;
       }

       const int vim_version = min_vim_version();
       if (*e == ':'
           && (s[0] != 'V'
               || strncmp(skipwhite(e + 1), "set", 3) == 0)
           && (s[3] == ':'
               || (vim_version >= vers && isdigit((uint8_t)s[3]))
               || (vim_version < vers && s[3] == '<')
               || (vim_version > vers && s[3] == '>')
               || (vim_version == vers && s[3] == '='))) {
         break;
       }
     }
   }
   prev = (uint8_t)(*s);
 }

 if (!*s) {
   return retval;
 }

 do {                                // skip over "ex:", "vi:" or "vim:"
   s++;
 } while (s[-1] != ':');

 size_t len = (size_t)(line_end - s);  // remember the line length so we can restore
                                       // 'line_end' after the copy
 char *linecopy;  // local copy of any modeline found
 s = linecopy = xstrnsave(s, len);     // copy the line, it will change

 line_end = s + len;                   // restore 'line_end'

 // prepare for emsg()
 estack_push(ETYPE_MODELINE, "modelines", lnum);
 ESTACK_CHECK_SETUP;

 bool end = false;
 while (end == false) {
   s = skipwhite(s);
   if (*s == NUL) {
     break;
   }

   // Find end of set command: ':' or end of line.
   // Skip over "\:", replacing it with ":".
   for (e = s; *e != ':' && *e != NUL; e++) {
     if (e[0] == '\\' && e[1] == ':') {
       memmove(e, e + 1, (size_t)(line_end - (e + 1)) + 1);    // +1 for NUL
       line_end--;
     }
   }
   if (*e == NUL) {
     end = true;
   }

   // If there is a "set" command, require a terminating ':' and
   // ignore the stuff after the ':'.
   // "vi:set opt opt opt: foo" -- foo not interpreted
   // "vi:opt opt opt: foo" -- foo interpreted
   // Accept "se" for compatibility with Elvis.
   if (strncmp(s, "set ", 4) == 0
       || strncmp(s, "se ", 3) == 0) {
     if (*e != ':') {                // no terminating ':'?
       break;
     }
     end = true;
     s += (*(s + 2) == ' ') ? 3 : 4;
   }
   *e = NUL;                         // truncate the set command

   if (*s != NUL) {                  // skip over an empty "::"
     const int secure_save = secure;
     const sctx_T save_current_sctx = current_sctx;
     current_sctx.sc_sid = SID_MODELINE;
     current_sctx.sc_seq = 0;
     current_sctx.sc_lnum = lnum;
     // Make sure no risky things are executed as a side effect.
     secure = 1;

     retval = do_set(s, OPT_MODELINE | OPT_LOCAL | flags);

     secure = secure_save;
     current_sctx = save_current_sctx;
     if (retval == FAIL) {                   // stop if error found
       break;
     }
   }
   s = (e == line_end) ? e : e + 1;  // advance to next part
                                     // careful not to go off the end
 }

 ESTACK_CHECK_NOW;
 estack_pop();
 xfree(linecopy);

 return retval;
}

/// @return  true if "buf" is a help buffer.
bool bt_help(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return buf != NULL && buf->b_help;
}

/// @return  true if "buf" is a normal buffer, 'buftype' is empty.
bool bt_normal(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return buf != NULL && buf->b_p_bt[0] == NUL;
}

/// @return  true if "buf" is the quickfix buffer.
bool bt_quickfix(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return buf != NULL && buf->b_p_bt[0] == 'q';
}

/// @return  true if "buf" is a terminal buffer.
bool bt_terminal(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return buf != NULL && buf->b_p_bt[0] == 't';
}

/// @return  true if "buf" is a "nofile", "acwrite", "terminal" or "prompt"
///          buffer.  This means the buffer name may not be a file name,
///          at least not for writing the buffer.
bool bt_nofilename(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return buf != NULL && ((buf->b_p_bt[0] == 'n' && buf->b_p_bt[2] == 'f')
                        || buf->b_p_bt[0] == 'a'
                        || buf->terminal
                        || buf->b_p_bt[0] == 'p');
}

/// @return  true if "buf" is a "nofile", "quickfix", "terminal" or "prompt"
///          buffer.  This means the buffer is not to be read from a file.
static bool bt_nofileread(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return buf != NULL && ((buf->b_p_bt[0] == 'n' && buf->b_p_bt[2] == 'f')
                        || buf->b_p_bt[0] == 't'
                        || buf->b_p_bt[0] == 'q'
                        || buf->b_p_bt[0] == 'p');
}

/// @return  true if "buf" has 'buftype' set to "nofile".
bool bt_nofile(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return buf != NULL && buf->b_p_bt[0] == 'n' && buf->b_p_bt[2] == 'f';
}

/// @return  true if "buf" is a "nowrite", "nofile", "terminal" or "prompt"
///          buffer.
bool bt_dontwrite(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 return buf != NULL && (buf->b_p_bt[0] == 'n'
                        || buf->terminal
                        || buf->b_p_bt[0] == 'p');
}

bool bt_dontwrite_msg(const buf_T *const buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
{
 if (bt_dontwrite(buf)) {
   emsg(_("E382: Cannot write, 'buftype' option is set"));
   return true;
 }
 return false;
}

/// @return  true if the buffer should be hidden, according to 'hidden', ":hide"
///          and 'bufhidden'.
bool buf_hide(const buf_T *const buf)
 FUNC_ATTR_PURE
{
 // 'bufhidden' overrules 'hidden' and ":hide", check it first
 switch (buf->b_p_bh[0]) {
 case 'u':                         // "unload"
 case 'w':                         // "wipe"
 case 'd':
   return false;           // "delete"
 case 'h':
   return true;            // "hide"
 }
 return p_hid || (cmdmod.cmod_flags & CMOD_HIDE);
}

/// @return  special buffer name or
///          NULL when the buffer has a normal file name.
char *buf_spname(buf_T *buf)
{
 if (bt_quickfix(buf)) {
   // Differentiate between the quickfix and location list buffers using
   // the buffer number stored in the global quickfix stack.
   if (buf->b_fnum == qf_stack_get_bufnr()) {
     return _(msg_qflist);
   }
   return _(msg_loclist);
 }
 // There is no _file_ when 'buftype' is "nofile", b_sfname
 // contains the name as specified by the user.
 if (bt_nofilename(buf)) {
   if (buf->b_fname != NULL) {
     return buf->b_fname;
   }
   if (buf == cmdwin_buf) {
     return _("[Command Line]");
   }
   if (bt_prompt(buf)) {
     return _("[Prompt]");
   }
   return _("[Scratch]");
 }
 if (buf->b_fname == NULL) {
   return buf_get_fname(buf);
 }
 return NULL;
}

/// Get "buf->b_fname", use "[No Name]" if it is NULL.
char *buf_get_fname(const buf_T *buf)
 FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
{
 if (buf->b_fname == NULL) {
   return _("[No Name]");
 }
 return buf->b_fname;
}

/// Set 'buflisted' for curbuf to "on" and trigger autocommands if it changed.
void set_buflisted(int on)
{
 if (on == curbuf->b_p_bl) {
   return;
 }

 curbuf->b_p_bl = on;
 if (on) {
   apply_autocmds(EVENT_BUFADD, NULL, NULL, false, curbuf);
 } else {
   apply_autocmds(EVENT_BUFDELETE, NULL, NULL, false, curbuf);
 }
}

/// Read the file for "buf" again and check if the contents changed.
/// Return true if it changed or this could not be checked.
///
/// @param  buf  buffer to check
///
/// @return  true if the buffer's contents have changed
bool buf_contents_changed(buf_T *buf)
 FUNC_ATTR_NONNULL_ALL
{
 bool differ = true;

 // Allocate a buffer without putting it in the buffer list.
 buf_T *newbuf = buflist_new(NULL, NULL, 1, BLN_DUMMY);
 if (newbuf == NULL) {
   return true;
 }

 // Force the 'fileencoding' and 'fileformat' to be equal.
 exarg_T ea;
 prep_exarg(&ea, buf);

 // Set curwin/curbuf to buf and save a few things.
 aco_save_T aco;
 aucmd_prepbuf(&aco, newbuf);

 // We don't want to trigger autocommands now, they may have nasty
 // side-effects like wiping buffers
 block_autocmds();

 if (ml_open(curbuf) == OK
     && readfile(buf->b_ffname, buf->b_fname,
                 0, 0, (linenr_T)MAXLNUM,
                 &ea, READ_NEW | READ_DUMMY, false) == OK) {
   // compare the two files line by line
   if (buf->b_ml.ml_line_count == curbuf->b_ml.ml_line_count) {
     differ = false;
     for (linenr_T lnum = 1; lnum <= curbuf->b_ml.ml_line_count; lnum++) {
       if (strcmp(ml_get_buf(buf, lnum), ml_get(lnum)) != 0) {
         differ = true;
         break;
       }
     }
   }
 }
 xfree(ea.cmd);

 // restore curwin/curbuf and a few other things
 aucmd_restbuf(&aco);

 if (curbuf != newbuf) {  // safety check
   wipe_buffer(newbuf, false);
 }

 unblock_autocmds();

 return differ;
}

/// Wipe out a (typically temporary) buffer.
/// @param aucmd  When true trigger autocommands.
void wipe_buffer(buf_T *buf, bool aucmd)
{
 if (!aucmd) {
   // Don't trigger BufDelete autocommands here.
   block_autocmds();
 }
 close_buffer(NULL, buf, DOBUF_WIPE, false, true);
 if (!aucmd) {
   unblock_autocmds();
 }
}

/// Creates or switches to a scratch buffer. :h special-buffers
/// Scratch buffer is:
///   - buftype=nofile bufhidden=hide noswapfile
///   - Always considered 'nomodified'
///
/// @param bufnr     Buffer to switch to, or 0 to create a new buffer.
/// @param bufname   Buffer name, or NULL.
///
/// @see curbufIsChanged()
///
/// @return  FAIL for failure, OK otherwise
int buf_open_scratch(handle_T bufnr, char *bufname)
{
 if (do_ecmd((int)bufnr, NULL, NULL, NULL, ECMD_ONE, ECMD_HIDE, NULL) == FAIL) {
   return FAIL;
 }
 if (bufname != NULL) {
   apply_autocmds(EVENT_BUFFILEPRE, NULL, NULL, false, curbuf);
   setfname(curbuf, bufname, NULL, true);
   apply_autocmds(EVENT_BUFFILEPOST, NULL, NULL, false, curbuf);
 }
 set_option_value_give_err(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("hide"), OPT_LOCAL);
 set_option_value_give_err(kOptBuftype, STATIC_CSTR_AS_OPTVAL("nofile"), OPT_LOCAL);
 set_option_value_give_err(kOptSwapfile, BOOLEAN_OPTVAL(false), OPT_LOCAL);
 RESET_BINDING(curwin);
 return OK;
}

bool buf_is_empty(buf_T *buf)
{
 return buf->b_ml.ml_line_count == 1 && *ml_get_buf(buf, 1) == NUL;
}

/// Increment b:changedtick value
///
/// Also checks b: for consistency in case of debug build.
///
/// @param[in,out]  buf  Buffer to increment value in.
void buf_inc_changedtick(buf_T *const buf)
 FUNC_ATTR_NONNULL_ALL
{
 buf_set_changedtick(buf, buf_get_changedtick(buf) + 1);
}

/// Set b:changedtick, also checking b: for consistency in debug build
///
/// @param[out]  buf  Buffer to set changedtick in.
/// @param[in]  changedtick  New value.
void buf_set_changedtick(buf_T *const buf, const varnumber_T changedtick)
 FUNC_ATTR_NONNULL_ALL
{
 typval_T old_val = buf->changedtick_di.di_tv;

#ifndef NDEBUG
 dictitem_T *const changedtick_di = tv_dict_find(buf->b_vars, S_LEN("changedtick"));
 assert(changedtick_di != NULL);
 assert(changedtick_di->di_tv.v_type == VAR_NUMBER);
 assert(changedtick_di->di_tv.v_lock == VAR_FIXED);
 // For some reason formatc does not like the below.
# ifndef UNIT_TESTING_LUA_PREPROCESSING
 assert(changedtick_di->di_flags == (DI_FLAGS_RO|DI_FLAGS_FIX));
# endif
 assert(changedtick_di == (dictitem_T *)&buf->changedtick_di);
#endif
 buf->changedtick_di.di_tv.vval.v_number = changedtick;

 if (tv_dict_is_watched(buf->b_vars)) {
   buf->b_locked++;
   tv_dict_watcher_notify(buf->b_vars,
                          (char *)buf->changedtick_di.di_key,
                          &buf->changedtick_di.di_tv,
                          &old_val);
   buf->b_locked--;
 }
}

/// Read the given buffer contents into a string.
void read_buffer_into(buf_T *buf, linenr_T start, linenr_T end, StringBuilder *sb)
 FUNC_ATTR_NONNULL_ALL
{
 assert(buf);
 assert(sb);

 if (buf->b_ml.ml_flags & ML_EMPTY) {
   return;
 }

 size_t written = 0;
 size_t len = 0;
 linenr_T lnum = start;
 char *lp = ml_get_buf(buf, lnum);
 size_t lplen = (size_t)ml_get_buf_len(buf, lnum);

 while (true) {
   if (lplen == 0) {
     len = 0;
   } else if (lp[written] == NL) {
     // NL -> NUL translation
     len = 1;
     kv_push(*sb, NUL);
   } else {
     char *s = vim_strchr(lp + written, NL);
     len = s == NULL ? lplen - written : (size_t)(s - (lp + written));
     kv_concat_len(*sb, lp + written, len);
   }

   if (len == lplen - written) {
     // Finished a line, add a NL, unless this line should not have one.
     if (lnum != end
         || (!buf->b_p_bin && buf->b_p_fixeol)
         || (lnum != buf->b_no_eol_lnum
             && (lnum != buf->b_ml.ml_line_count || buf->b_p_eol))) {
       kv_push(*sb, NL);
     }
     lnum++;
     if (lnum > end) {
       break;
     }
     lp = ml_get_buf(buf, lnum);
     lplen = (size_t)ml_get_buf_len(buf, lnum);
     written = 0;
   } else if (len > 0) {
     written += len;
   }
 }
}