neovim

Neovim text editor
git clone https://git.dasho.dev/neovim.git
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commit 960170e4469b96c5c3d06ba1bb84c9edeaa04b8b
parent 2af9fac0a6ce3b01f22802511cf1ed7b0734cb2e
Author: zeertzjq <zeertzjq@outlook.com>
Date:   Sat, 30 Sep 2023 19:36:33 +0800

vim-patch:9.0.1366: functions for setting options are in random order (#25440)

Problem:    Functions for setting options are in random order.
Solution:   Sort functions alphabetically. (Yegappan Lakshmanan,
            closes vim/vim#12082)

https://github.com/vim/vim/commit/ad60898aa47b44fdece12d28c471fb50df27fb50

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Diffstat:

Msrc/nvim/option.c | 1160++++++++++++++++++++++++++++++++++++++++----------------------------------------


Msrc/nvim/optionstr.c | 1706++++++++++++++++++++++++++++++++++++++++---------------------------------------


2 files changed, 1436 insertions(+), 1430 deletions(-)

diff --git a/src/nvim/option.c b/src/nvim/option.c
@@ -2037,74 +2037,149 @@ static const char *did_set_force_off(bool *doskip)
   return NULL;
 }
 
-/// Process the updated 'langremap' option value.
-static const char *did_set_langremap(optset_T *args FUNC_ATTR_UNUSED)
+/// Process the updated 'arabic' option value.
+static const char *did_set_arabic(optset_T *args)
 {
-  // 'langremap' -> !'langnoremap'
-  p_lnr = !p_lrm;
+  win_T *win = (win_T *)args->os_win;
+  const char *errmsg = NULL;
+
+  if (win->w_p_arab) {
+    // 'arabic' is set, handle various sub-settings.
+    if (!p_tbidi) {
+      // set rightleft mode
+      if (!win->w_p_rl) {
+        win->w_p_rl = true;
+        changed_window_setting();
+      }
+
+      // Enable Arabic shaping (major part of what Arabic requires)
+      if (!p_arshape) {
+        p_arshape = true;
+        redraw_all_later(UPD_NOT_VALID);
+      }
+    }
+
+    // Arabic requires a utf-8 encoding, inform the user if it's not
+    // set.
+    if (strcmp(p_enc, "utf-8") != 0) {
+      static char *w_arabic = N_("W17: Arabic requires UTF-8, do ':set encoding=utf-8'");
+
+      msg_source(HL_ATTR(HLF_W));
+      msg(_(w_arabic), HL_ATTR(HLF_W));
+      set_vim_var_string(VV_WARNINGMSG, _(w_arabic), -1);
+    }
+
+    // set 'delcombine'
+    p_deco = true;
+
+    // Force-set the necessary keymap for arabic.
+    errmsg = set_option_value("keymap", STATIC_CSTR_AS_OPTVAL("arabic"), OPT_LOCAL);
+  } else {
+    // 'arabic' is reset, handle various sub-settings.
+    if (!p_tbidi) {
+      // reset rightleft mode
+      if (win->w_p_rl) {
+        win->w_p_rl = false;
+        changed_window_setting();
+      }
+
+      // 'arabicshape' isn't reset, it is a global option and
+      // another window may still need it "on".
+    }
+
+    // 'delcombine' isn't reset, it is a global option and another
+    // window may still want it "on".
+
+    // Revert to the default keymap
+    curbuf->b_p_iminsert = B_IMODE_NONE;
+    curbuf->b_p_imsearch = B_IMODE_USE_INSERT;
+  }
+
+  return errmsg;
+}
+
+/// Process the updated 'autochdir' option value.
+static const char *did_set_autochdir(optset_T *args FUNC_ATTR_UNUSED)
+{
+  // Change directories when the 'acd' option is set now.
+  do_autochdir();
   return NULL;
 }
 
-/// Process the updated 'langnoremap' option value.
-static const char *did_set_langnoremap(optset_T *args FUNC_ATTR_UNUSED)
+/// Process the updated 'binary' option value.
+static const char *did_set_binary(optset_T *args)
 {
-  // 'langnoremap' -> !'langremap'
-  p_lrm = !p_lnr;
+  buf_T *buf = (buf_T *)args->os_buf;
+
+  // when 'bin' is set also set some other options
+  set_options_bin((int)args->os_oldval.boolean, buf->b_p_bin, args->os_flags);
+  redraw_titles();
+
   return NULL;
 }
 
-/// Process the updated 'undofile' option value.
-static const char *did_set_undofile(optset_T *args)
+/// Called when the 'breakat' option changes value.
+static const char *did_set_breakat(optset_T *args FUNC_ATTR_UNUSED)
 {
-  // Only take action when the option was set.
-  if (!curbuf->b_p_udf && !p_udf) {
-    return NULL;
+  for (int i = 0; i < 256; i++) {
+    breakat_flags[i] = false;
   }
 
-  // When reset we do not delete the undo file, the option may be set again
-  // without making any changes in between.
-  uint8_t hash[UNDO_HASH_SIZE];
-
-  FOR_ALL_BUFFERS(bp) {
-    // When 'undofile' is set globally: for every buffer, otherwise
-    // only for the current buffer: Try to read in the undofile,
-    // if one exists, the buffer wasn't changed and the buffer was
-    // loaded
-    if ((curbuf == bp
-         || (args->os_flags & OPT_GLOBAL) || args->os_flags == 0)
-        && !bufIsChanged(bp) && bp->b_ml.ml_mfp != NULL) {
-      u_compute_hash(bp, hash);
-      u_read_undo(NULL, hash, bp->b_fname);
+  if (p_breakat != NULL) {
+    for (char *p = p_breakat; *p; p++) {
+      breakat_flags[(uint8_t)(*p)] = true;
     }
   }
 
   return NULL;
 }
 
-/// Process the updated 'readonly' option value.
-static const char *did_set_readonly(optset_T *args)
+/// Process the updated 'buflisted' option value.
+static const char *did_set_buflisted(optset_T *args)
 {
-  // when 'readonly' is reset globally, also reset readonlymode
-  if (!curbuf->b_p_ro && (args->os_flags & OPT_LOCAL) == 0) {
-    readonlymode = false;
+  buf_T *buf = (buf_T *)args->os_buf;
+
+  // when 'buflisted' changes, trigger autocommands
+  if (args->os_oldval.boolean != buf->b_p_bl) {
+    apply_autocmds(buf->b_p_bl ? EVENT_BUFADD : EVENT_BUFDELETE,
+                   NULL, NULL, true, buf);
   }
+  return NULL;
+}
 
-  // when 'readonly' is set may give W10 again
-  if (curbuf->b_p_ro) {
-    curbuf->b_did_warn = false;
+/// Process the new 'cmdheight' option value.
+static const char *did_set_cmdheight(optset_T *args)
+{
+  OptInt old_value = args->os_oldval.number;
+
+  if (ui_has(kUIMessages)) {
+    p_ch = 0;
+  }
+  if (p_ch > Rows - min_rows() + 1) {
+    p_ch = Rows - min_rows() + 1;
   }
 
-  redraw_titles();
+  // if p_ch changed value, change the command line height
+  // Only compute the new window layout when startup has been
+  // completed. Otherwise the frame sizes may be wrong.
+  if ((p_ch != old_value
+       || tabline_height() + global_stl_height() + topframe->fr_height != Rows - p_ch)
+      && full_screen) {
+    command_height();
+  }
 
   return NULL;
 }
 
-/// Process the updated 'modifiable' option value.
-static const char *did_set_modifiable(optset_T *args FUNC_ATTR_UNUSED)
+/// Process the updated 'diff' option value.
+static const char *did_set_diff(optset_T *args)
 {
-  // when 'modifiable' is changed, redraw the window title
-  redraw_titles();
-
+  win_T *win = (win_T *)args->os_win;
+  // May add or remove the buffer from the list of diff buffers.
+  diff_buf_adjust(win);
+  if (foldmethodIsDiff(win)) {
+    foldUpdateAll(win);
+  }
   return NULL;
 }
 
@@ -2117,76 +2192,205 @@ static const char *did_set_eof_eol_fixeol_bomb(optset_T *args FUNC_ATTR_UNUSED)
   return NULL;
 }
 
-/// Process the updated 'binary' option value.
-static const char *did_set_binary(optset_T *args)
+/// Process the updated 'equalalways' option value.
+static const char *did_set_equalalways(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  win_T *win = (win_T *)args->os_win;
+  if (p_ea && !args->os_oldval.boolean) {
+    win_equal(win, false, 0);
+  }
 
-  // when 'bin' is set also set some other options
-  set_options_bin((int)args->os_oldval.boolean, buf->b_p_bin, args->os_flags);
-  redraw_titles();
+  return NULL;
+}
 
+/// Process the new 'foldlevel' option value.
+static const char *did_set_foldlevel(optset_T *args FUNC_ATTR_UNUSED)
+{
+  newFoldLevel();
   return NULL;
 }
 
-/// Process the updated 'buflisted' option value.
-static const char *did_set_buflisted(optset_T *args)
+/// Process the new 'foldminlines' option value.
+static const char *did_set_foldminlines(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
+  win_T *win = (win_T *)args->os_win;
+  foldUpdateAll(win);
+  return NULL;
+}
 
-  // when 'buflisted' changes, trigger autocommands
-  if (args->os_oldval.boolean != buf->b_p_bl) {
-    apply_autocmds(buf->b_p_bl ? EVENT_BUFADD : EVENT_BUFDELETE,
-                   NULL, NULL, true, buf);
+/// Process the new 'foldnestmax' option value.
+static const char *did_set_foldnestmax(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+  if (foldmethodIsSyntax(win) || foldmethodIsIndent(win)) {
+    foldUpdateAll(win);
   }
   return NULL;
 }
 
-/// Process the updated 'swapfile' option value.
-static const char *did_set_swapfile(optset_T *args)
+/// Process the new 'helpheight' option value.
+static const char *did_set_helpheight(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
-  // when 'swf' is set, create swapfile, when reset remove swapfile
-  if (buf->b_p_swf && p_uc) {
-    ml_open_file(buf);                     // create the swap file
-  } else {
-    // no need to reset curbuf->b_may_swap, ml_open_file() will check
-    // buf->b_p_swf
-    mf_close_file(buf, true);              // remove the swap file
+  // Change window height NOW
+  if (!ONE_WINDOW) {
+    buf_T *buf = (buf_T *)args->os_buf;
+    win_T *win = (win_T *)args->os_win;
+    if (buf->b_help && win->w_height < p_hh) {
+      win_setheight((int)p_hh);
+    }
   }
+
   return NULL;
 }
 
-/// Process the updated 'paste' option value.
-static const char *did_set_paste(optset_T *args FUNC_ATTR_UNUSED)
+/// Process the updated 'hlsearch' option value.
+static const char *did_set_hlsearch(optset_T *args FUNC_ATTR_UNUSED)
 {
-  static int old_p_paste = false;
-  static int save_sm = 0;
-  static int save_sta = 0;
-  static int save_ru = 0;
-  static int save_ri = 0;
+  // when 'hlsearch' is set or reset: reset no_hlsearch
+  set_no_hlsearch(false);
+  return NULL;
+}
 
-  if (p_paste) {
-    // Paste switched from off to on.
-    // Save the current values, so they can be restored later.
-    if (!old_p_paste) {
-      // save options for each buffer
-      FOR_ALL_BUFFERS(buf) {
-        buf->b_p_tw_nopaste = buf->b_p_tw;
-        buf->b_p_wm_nopaste = buf->b_p_wm;
-        buf->b_p_sts_nopaste = buf->b_p_sts;
-        buf->b_p_ai_nopaste = buf->b_p_ai;
-        buf->b_p_et_nopaste = buf->b_p_et;
-        if (buf->b_p_vsts_nopaste) {
-          xfree(buf->b_p_vsts_nopaste);
-        }
-        buf->b_p_vsts_nopaste = buf->b_p_vsts && buf->b_p_vsts != empty_option
-                                    ? xstrdup(buf->b_p_vsts)
-                                    : NULL;
-      }
+/// Process the updated 'ignorecase' option value.
+static const char *did_set_ignorecase(optset_T *args FUNC_ATTR_UNUSED)
+{
+  // when 'ignorecase' is set or reset and 'hlsearch' is set, redraw
+  if (p_hls) {
+    redraw_all_later(UPD_SOME_VALID);
+  }
+  return NULL;
+}
 
-      // save global options
-      save_sm = p_sm;
+/// Process the new 'iminset' option value.
+static const char *did_set_iminsert(optset_T *args FUNC_ATTR_UNUSED)
+{
+  showmode();
+  // Show/unshow value of 'keymap' in status lines.
+  status_redraw_curbuf();
+
+  return NULL;
+}
+
+/// Process the updated 'langnoremap' option value.
+static const char *did_set_langnoremap(optset_T *args FUNC_ATTR_UNUSED)
+{
+  // 'langnoremap' -> !'langremap'
+  p_lrm = !p_lnr;
+  return NULL;
+}
+
+/// Process the updated 'langremap' option value.
+static const char *did_set_langremap(optset_T *args FUNC_ATTR_UNUSED)
+{
+  // 'langremap' -> !'langnoremap'
+  p_lnr = !p_lrm;
+  return NULL;
+}
+
+/// Process the new 'laststatus' option value.
+static const char *did_set_laststatus(optset_T *args)
+{
+  OptInt old_value = args->os_oldval.number;
+  OptInt value = args->os_newval.number;
+
+  // When switching to global statusline, decrease topframe height
+  // Also clear the cmdline to remove the ruler if there is one
+  if (value == 3 && old_value != 3) {
+    frame_new_height(topframe, topframe->fr_height - STATUS_HEIGHT, false, false);
+    (void)win_comp_pos();
+    clear_cmdline = true;
+  }
+  // When switching from global statusline, increase height of topframe by STATUS_HEIGHT
+  // in order to to re-add the space that was previously taken by the global statusline
+  if (old_value == 3 && value != 3) {
+    frame_new_height(topframe, topframe->fr_height + STATUS_HEIGHT, false, false);
+    (void)win_comp_pos();
+  }
+
+  last_status(false);  // (re)set last window status line.
+  return NULL;
+}
+
+/// Process the updated 'lisp' option value.
+static const char *did_set_lisp(optset_T *args)
+{
+  buf_T *buf = (buf_T *)args->os_buf;
+  // When 'lisp' option changes include/exclude '-' in keyword characters.
+  (void)buf_init_chartab(buf, false);          // ignore errors
+  return NULL;
+}
+
+/// Process the updated 'modifiable' option value.
+static const char *did_set_modifiable(optset_T *args FUNC_ATTR_UNUSED)
+{
+  // when 'modifiable' is changed, redraw the window title
+  redraw_titles();
+
+  return NULL;
+}
+
+/// Process the updated 'modified' option value.
+static const char *did_set_modified(optset_T *args)
+{
+  buf_T *buf = (buf_T *)args->os_buf;
+  if (!args->os_newval.boolean) {
+    save_file_ff(buf);  // Buffer is unchanged
+  }
+  redraw_titles();
+  modified_was_set = (int)args->os_newval.boolean;
+  return NULL;
+}
+
+/// Process the updated 'number' or 'relativenumber' option value.
+static const char *did_set_number_relativenumber(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+  if (*win->w_p_stc != NUL) {
+    // When 'relativenumber'/'number' is changed and 'statuscolumn' is set, reset width.
+    win->w_nrwidth_line_count = 0;
+  }
+  return NULL;
+}
+
+/// Process the new 'numberwidth' option value.
+static const char *did_set_numberwidth(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+  win->w_nrwidth_line_count = 0;  // trigger a redraw
+
+  return NULL;
+}
+
+/// Process the updated 'paste' option value.
+static const char *did_set_paste(optset_T *args FUNC_ATTR_UNUSED)
+{
+  static int old_p_paste = false;
+  static int save_sm = 0;
+  static int save_sta = 0;
+  static int save_ru = 0;
+  static int save_ri = 0;
+
+  if (p_paste) {
+    // Paste switched from off to on.
+    // Save the current values, so they can be restored later.
+    if (!old_p_paste) {
+      // save options for each buffer
+      FOR_ALL_BUFFERS(buf) {
+        buf->b_p_tw_nopaste = buf->b_p_tw;
+        buf->b_p_wm_nopaste = buf->b_p_wm;
+        buf->b_p_sts_nopaste = buf->b_p_sts;
+        buf->b_p_ai_nopaste = buf->b_p_ai;
+        buf->b_p_et_nopaste = buf->b_p_et;
+        if (buf->b_p_vsts_nopaste) {
+          xfree(buf->b_p_vsts_nopaste);
+        }
+        buf->b_p_vsts_nopaste = buf->b_p_vsts && buf->b_p_vsts != empty_option
+                                    ? xstrdup(buf->b_p_vsts)
+                                    : NULL;
+      }
+
+      // save global options
+      save_sm = p_sm;
       save_sta = p_sta;
       save_ru = p_ru;
       save_ri = p_ri;
@@ -2273,400 +2477,138 @@ static const char *did_set_paste(optset_T *args FUNC_ATTR_UNUSED)
     p_tw = p_tw_nopaste;
     p_wm = p_wm_nopaste;
     if (p_vsts) {
-      free_string_option(p_vsts);
-    }
-    p_vsts = p_vsts_nopaste ? xstrdup(p_vsts_nopaste) : empty_option;
-  }
-
-  old_p_paste = p_paste;
-
-  // Remember where the dependent options were reset
-  didset_options_sctx((OPT_LOCAL | OPT_GLOBAL), p_paste_dep_opts);
-
-  return NULL;
-}
-
-/// Process the updated 'ignorecase' option value.
-static const char *did_set_ignorecase(optset_T *args FUNC_ATTR_UNUSED)
-{
-  // when 'ignorecase' is set or reset and 'hlsearch' is set, redraw
-  if (p_hls) {
-    redraw_all_later(UPD_SOME_VALID);
-  }
-  return NULL;
-}
-
-/// Process the updated 'hlsearch' option value.
-static const char *did_set_hlsearch(optset_T *args FUNC_ATTR_UNUSED)
-{
-  // when 'hlsearch' is set or reset: reset no_hlsearch
-  set_no_hlsearch(false);
-  return NULL;
-}
-
-/// Process the updated 'scrollbind' option value.
-static const char *did_set_scrollbind(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-
-  // when 'scrollbind' is set: snapshot the current position to avoid a jump
-  // at the end of normal_cmd()
-  if (!win->w_p_scb) {
-    return NULL;
-  }
-  do_check_scrollbind(false);
-  win->w_scbind_pos = win->w_topline;
-  return NULL;
-}
-
-/// Process the updated 'previewwindow' option value.
-static const char *did_set_previewwindow(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-
-  if (!win->w_p_pvw) {
-    return NULL;
-  }
-
-  // There can be only one window with 'previewwindow' set.
-  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
-    if (wp->w_p_pvw && wp != win) {
-      win->w_p_pvw = false;
-      args->os_doskip = true;
-      return e_preview_window_already_exists;
-    }
-  }
-
-  return NULL;
-}
-
-/// Process the updated 'lisp' option value.
-static const char *did_set_lisp(optset_T *args)
-{
-  buf_T *buf = (buf_T *)args->os_buf;
-  // When 'lisp' option changes include/exclude '-' in keyword characters.
-  (void)buf_init_chartab(buf, false);          // ignore errors
-  return NULL;
-}
-
-/// Process the updated 'title' or the 'icon' option value.
-static const char *did_set_title_icon(optset_T *args FUNC_ATTR_UNUSED)
-{
-  // when 'title' changed, may need to change the title; same for 'icon'
-  did_set_title();
-  return NULL;
-}
-
-/// Process the updated 'modified' option value.
-static const char *did_set_modified(optset_T *args)
-{
-  buf_T *buf = (buf_T *)args->os_buf;
-  if (!args->os_newval.boolean) {
-    save_file_ff(buf);  // Buffer is unchanged
-  }
-  redraw_titles();
-  modified_was_set = (int)args->os_newval.boolean;
-  return NULL;
-}
-
-#ifdef BACKSLASH_IN_FILENAME
-/// Process the updated 'shellslash' option value.
-static const char *did_set_shellslash(optset_T *args FUNC_ATTR_UNUSED)
-{
-  if (p_ssl) {
-    psepc = '/';
-    psepcN = '\\';
-    pseps[0] = '/';
-  } else {
-    psepc = '\\';
-    psepcN = '/';
-    pseps[0] = '\\';
-  }
-
-  // need to adjust the file name arguments and buffer names.
-  buflist_slash_adjust();
-  alist_slash_adjust();
-  scriptnames_slash_adjust();
-  return NULL;
-}
-#endif
-
-/// Process the updated 'wrap' option value.
-static const char *did_set_wrap(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-
-  // If 'wrap' is set, set w_leftcol to zero.
-  if (win->w_p_wrap) {
-    win->w_leftcol = 0;
-  }
-  return NULL;
-}
-
-/// Process the updated 'equalalways' option value.
-static const char *did_set_equalalways(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  if (p_ea && !args->os_oldval.boolean) {
-    win_equal(win, false, 0);
-  }
-
-  return NULL;
-}
-
-/// Process the updated 'autochdir' option value.
-static const char *did_set_autochdir(optset_T *args FUNC_ATTR_UNUSED)
-{
-  // Change directories when the 'acd' option is set now.
-  do_autochdir();
-  return NULL;
-}
-
-/// Process the updated 'diff' option value.
-static const char *did_set_diff(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  // May add or remove the buffer from the list of diff buffers.
-  diff_buf_adjust(win);
-  if (foldmethodIsDiff(win)) {
-    foldUpdateAll(win);
-  }
-  return NULL;
-}
-
-/// Process the updated 'spell' option value.
-static const char *did_set_spell(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  if (win->w_p_spell) {
-    return parse_spelllang(win);
-  }
-
-  return NULL;
-}
-
-/// Process the updated 'arabic' option value.
-static const char *did_set_arabic(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  const char *errmsg = NULL;
-
-  if (win->w_p_arab) {
-    // 'arabic' is set, handle various sub-settings.
-    if (!p_tbidi) {
-      // set rightleft mode
-      if (!win->w_p_rl) {
-        win->w_p_rl = true;
-        changed_window_setting();
-      }
-
-      // Enable Arabic shaping (major part of what Arabic requires)
-      if (!p_arshape) {
-        p_arshape = true;
-        redraw_all_later(UPD_NOT_VALID);
-      }
-    }
-
-    // Arabic requires a utf-8 encoding, inform the user if it's not
-    // set.
-    if (strcmp(p_enc, "utf-8") != 0) {
-      static char *w_arabic = N_("W17: Arabic requires UTF-8, do ':set encoding=utf-8'");
-
-      msg_source(HL_ATTR(HLF_W));
-      msg(_(w_arabic), HL_ATTR(HLF_W));
-      set_vim_var_string(VV_WARNINGMSG, _(w_arabic), -1);
-    }
-
-    // set 'delcombine'
-    p_deco = true;
-
-    // Force-set the necessary keymap for arabic.
-    errmsg = set_option_value("keymap", STATIC_CSTR_AS_OPTVAL("arabic"), OPT_LOCAL);
-  } else {
-    // 'arabic' is reset, handle various sub-settings.
-    if (!p_tbidi) {
-      // reset rightleft mode
-      if (win->w_p_rl) {
-        win->w_p_rl = false;
-        changed_window_setting();
-      }
-
-      // 'arabicshape' isn't reset, it is a global option and
-      // another window may still need it "on".
-    }
-
-    // 'delcombine' isn't reset, it is a global option and another
-    // window may still want it "on".
-
-    // Revert to the default keymap
-    curbuf->b_p_iminsert = B_IMODE_NONE;
-    curbuf->b_p_imsearch = B_IMODE_USE_INSERT;
-  }
-
-  return errmsg;
-}
-
-/// Process the updated 'number' or 'relativenumber' option value.
-static const char *did_set_number_relativenumber(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  if (*win->w_p_stc != NUL) {
-    // When 'relativenumber'/'number' is changed and 'statuscolumn' is set, reset width.
-    win->w_nrwidth_line_count = 0;
-  }
-  return NULL;
-}
-
-/// Set the value of a boolean option, taking care of side effects
-///
-/// @param[in]  opt_idx  Option index in options[] table.
-/// @param[out]  varp  Pointer to the option variable.
-/// @param[in]  value  New value.
-/// @param[in]  opt_flags  OPT_LOCAL and/or OPT_GLOBAL.
-///
-/// @return NULL on success, error message on error.
-static const char *set_bool_option(const int opt_idx, char *const varp, const int value,
-                                   const int opt_flags)
-{
-  int old_value = *(int *)varp;
-  int old_global_value = 0;
-
-  // Disallow changing some options from secure mode
-  if ((secure || sandbox != 0)
-      && (options[opt_idx].flags & P_SECURE)) {
-    return e_secure;
+      free_string_option(p_vsts);
+    }
+    p_vsts = p_vsts_nopaste ? xstrdup(p_vsts_nopaste) : empty_option;
   }
 
-  // Save the global value before changing anything. This is needed as for
-  // a global-only option setting the "local value" in fact sets the global
-  // value (since there is only one value).
-  if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0) {
-    old_global_value = *(int *)get_varp_scope(&(options[opt_idx]), OPT_GLOBAL);
-  }
+  old_p_paste = p_paste;
 
-  *(int *)varp = value;             // set the new value
-  // Remember where the option was set.
-  set_option_sctx_idx(opt_idx, opt_flags, current_sctx);
+  // Remember where the dependent options were reset
+  didset_options_sctx((OPT_LOCAL | OPT_GLOBAL), p_paste_dep_opts);
 
-  // May set global value for local option.
-  if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0) {
-    *(int *)get_varp_scope(&(options[opt_idx]), OPT_GLOBAL) = value;
-  }
+  return NULL;
+}
 
-  // Handle side effects for changing a bool option.
-  const char *errmsg = NULL;
-  bool doskip = false;
-  if ((int *)varp == &p_force_on) {
-    errmsg = did_set_force_on(&doskip);
-  } else if ((int *)varp == &p_force_off) {
-    errmsg = did_set_force_off(&doskip);
-  } else if (options[opt_idx].opt_did_set_cb != NULL) {
-    optset_T args = {
-      .os_varp = varp,
-      .os_flags = opt_flags,
-      .os_oldval.boolean = old_value,
-      .os_newval.boolean = value,
-      .os_doskip = false,
-      .os_errbuf = NULL,
-      .os_errbuflen = 0,
-      .os_buf = curbuf,
-      .os_win = curwin
-    };
+/// Process the updated 'previewwindow' option value.
+static const char *did_set_previewwindow(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
 
-    errmsg = options[opt_idx].opt_did_set_cb(&args);
-    doskip = args.os_doskip;
-  }
-  if (doskip) {
-    return errmsg;
+  if (!win->w_p_pvw) {
+    return NULL;
   }
 
-  // after handling side effects, call autocommand
-
-  options[opt_idx].flags |= P_WAS_SET;
+  // There can be only one window with 'previewwindow' set.
+  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+    if (wp->w_p_pvw && wp != win) {
+      win->w_p_pvw = false;
+      args->os_doskip = true;
+      return e_preview_window_already_exists;
+    }
+  }
 
-  apply_optionset_autocmd(opt_idx, opt_flags,
-                          (long)(old_value ? true : false),
-                          (long)(old_global_value ? true : false),
-                          (long)(value ? true : false), NULL);
+  return NULL;
+}
 
-  if (options[opt_idx].flags & P_UI_OPTION) {
-    ui_call_option_set(cstr_as_string(options[opt_idx].fullname),
-                       BOOLEAN_OBJ(*varp));
-  }
-  if ((int *)varp == &p_ru || (int *)varp == &p_sc) {
-    // in case 'ruler' or 'showcmd' changed
-    comp_col();
-  }
-  if (curwin->w_curswant != MAXCOL
-      && (options[opt_idx].flags & (P_CURSWANT | P_RALL)) != 0) {
-    curwin->w_set_curswant = true;
+/// Process the new 'pumblend' option value.
+static const char *did_set_pumblend(optset_T *args FUNC_ATTR_UNUSED)
+{
+  p_pb = MAX(MIN(p_pb, 100), 0);
+  hl_invalidate_blends();
+  pum_grid.blending = (p_pb > 0);
+  if (pum_drawn()) {
+    pum_redraw();
   }
-  check_redraw(options[opt_idx].flags);
 
-  return errmsg;
+  return NULL;
 }
 
-/// Process the new 'winheight' value.
-static const char *did_set_winheight(optset_T *args)
+/// Process the updated 'readonly' option value.
+static const char *did_set_readonly(optset_T *args)
 {
-  // Change window height NOW
-  if (!ONE_WINDOW) {
-    win_T *win = (win_T *)args->os_win;
-    if (win->w_height < p_wh) {
-      win_setheight((int)p_wh);
-    }
+  // when 'readonly' is reset globally, also reset readonlymode
+  if (!curbuf->b_p_ro && (args->os_flags & OPT_LOCAL) == 0) {
+    readonlymode = false;
+  }
+
+  // when 'readonly' is set may give W10 again
+  if (curbuf->b_p_ro) {
+    curbuf->b_did_warn = false;
   }
 
+  redraw_titles();
+
   return NULL;
 }
 
-/// Process the new 'helpheight' option value.
-static const char *did_set_helpheight(optset_T *args)
+/// Process the new 'scrollback' option value.
+static const char *did_set_scrollback(optset_T *args)
 {
-  // Change window height NOW
-  if (!ONE_WINDOW) {
-    buf_T *buf = (buf_T *)args->os_buf;
-    win_T *win = (win_T *)args->os_win;
-    if (buf->b_help && win->w_height < p_hh) {
-      win_setheight((int)p_hh);
-    }
-  }
+  buf_T *buf = (buf_T *)args->os_buf;
+  OptInt old_value = args->os_oldval.number;
+  OptInt value = args->os_newval.number;
 
+  if (buf->terminal && value < old_value) {
+    // Force the scrollback to take immediate effect only when decreasing it.
+    on_scrollback_option_changed(buf->terminal);
+  }
   return NULL;
 }
 
-/// Process the new 'winwidth' option value.
-static const char *did_set_winwidth(optset_T *args)
+/// Process the updated 'scrollbind' option value.
+static const char *did_set_scrollbind(optset_T *args)
 {
   win_T *win = (win_T *)args->os_win;
 
-  if (!ONE_WINDOW && win->w_width < p_wiw) {
-    win_setwidth((int)p_wiw);
+  // when 'scrollbind' is set: snapshot the current position to avoid a jump
+  // at the end of normal_cmd()
+  if (!win->w_p_scb) {
+    return NULL;
   }
+  do_check_scrollbind(false);
+  win->w_scbind_pos = win->w_topline;
   return NULL;
 }
 
-/// Process the new 'laststatus' option value.
-static const char *did_set_laststatus(optset_T *args)
+#ifdef BACKSLASH_IN_FILENAME
+/// Process the updated 'shellslash' option value.
+static const char *did_set_shellslash(optset_T *args FUNC_ATTR_UNUSED)
 {
-  OptInt old_value = args->os_oldval.number;
-  OptInt value = args->os_newval.number;
+  if (p_ssl) {
+    psepc = '/';
+    psepcN = '\\';
+    pseps[0] = '/';
+  } else {
+    psepc = '\\';
+    psepcN = '/';
+    pseps[0] = '\\';
+  }
 
-  // When switching to global statusline, decrease topframe height
-  // Also clear the cmdline to remove the ruler if there is one
-  if (value == 3 && old_value != 3) {
-    frame_new_height(topframe, topframe->fr_height - STATUS_HEIGHT, false, false);
-    (void)win_comp_pos();
-    clear_cmdline = true;
+  // need to adjust the file name arguments and buffer names.
+  buflist_slash_adjust();
+  alist_slash_adjust();
+  scriptnames_slash_adjust();
+  return NULL;
+}
+#endif
+
+/// Process the new 'shiftwidth' or the 'tabstop' option value.
+static const char *did_set_shiftwidth_tabstop(optset_T *args)
+{
+  buf_T *buf = (buf_T *)args->os_buf;
+  win_T *win = (win_T *)args->os_win;
+  OptInt *pp = (OptInt *)args->os_varp;
+
+  if (foldmethodIsIndent(win)) {
+    foldUpdateAll(win);
   }
-  // When switching from global statusline, increase height of topframe by STATUS_HEIGHT
-  // in order to to re-add the space that was previously taken by the global statusline
-  if (old_value == 3 && value != 3) {
-    frame_new_height(topframe, topframe->fr_height + STATUS_HEIGHT, false, false);
-    (void)win_comp_pos();
+  // When 'shiftwidth' changes, or it's zero and 'tabstop' changes:
+  // parse 'cinoptions'.
+  if (pp == &buf->b_p_sw || buf->b_p_sw == 0) {
+    parse_cino(buf);
   }
 
-  last_status(false);  // (re)set last window status line.
   return NULL;
 }
 
@@ -2691,68 +2633,47 @@ static const char *did_set_smoothscroll(optset_T *args FUNC_ATTR_UNUSED)
   return NULL;
 }
 
-/// Process the new 'foldlevel' option value.
-static const char *did_set_foldlevel(optset_T *args FUNC_ATTR_UNUSED)
-{
-  newFoldLevel();
-  return NULL;
-}
-
-/// Process the new 'foldminlines' option value.
-static const char *did_set_foldminlines(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  foldUpdateAll(win);
-  return NULL;
-}
-
-/// Process the new 'foldnestmax' option value.
-static const char *did_set_foldnestmax(optset_T *args)
+/// Process the updated 'spell' option value.
+static const char *did_set_spell(optset_T *args)
 {
   win_T *win = (win_T *)args->os_win;
-  if (foldmethodIsSyntax(win) || foldmethodIsIndent(win)) {
-    foldUpdateAll(win);
+  if (win->w_p_spell) {
+    return parse_spelllang(win);
   }
+
   return NULL;
 }
 
-/// Process the new 'shiftwidth' or the 'tabstop' option value.
-static const char *did_set_shiftwidth_tabstop(optset_T *args)
+/// Process the updated 'swapfile' option value.
+static const char *did_set_swapfile(optset_T *args)
 {
   buf_T *buf = (buf_T *)args->os_buf;
-  win_T *win = (win_T *)args->os_win;
-  OptInt *pp = (OptInt *)args->os_varp;
-
-  if (foldmethodIsIndent(win)) {
-    foldUpdateAll(win);
-  }
-  // When 'shiftwidth' changes, or it's zero and 'tabstop' changes:
-  // parse 'cinoptions'.
-  if (pp == &buf->b_p_sw || buf->b_p_sw == 0) {
-    parse_cino(buf);
+  // when 'swf' is set, create swapfile, when reset remove swapfile
+  if (buf->b_p_swf && p_uc) {
+    ml_open_file(buf);                     // create the swap file
+  } else {
+    // no need to reset curbuf->b_may_swap, ml_open_file() will check
+    // buf->b_p_swf
+    mf_close_file(buf, true);              // remove the swap file
   }
-
-  return NULL;
-}
-
-/// Process the new 'iminset' option value.
-static const char *did_set_iminsert(optset_T *args FUNC_ATTR_UNUSED)
-{
-  showmode();
-  // Show/unshow value of 'keymap' in status lines.
-  status_redraw_curbuf();
-
   return NULL;
 }
 
-/// Process the new 'window' option value.
-static const char *did_set_window(optset_T *args FUNC_ATTR_UNUSED)
+/// Process the new 'textwidth' option value.
+static const char *did_set_textwidth(optset_T *args FUNC_ATTR_UNUSED)
 {
-  if (p_window < 1) {
-    p_window = Rows - 1;
-  } else if (p_window >= Rows) {
-    p_window = Rows - 1;
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    check_colorcolumn(wp);
   }
+
+  return NULL;
+}
+
+/// Process the updated 'title' or the 'icon' option value.
+static const char *did_set_title_icon(optset_T *args FUNC_ATTR_UNUSED)
+{
+  // when 'title' changed, may need to change the title; same for 'icon'
+  did_set_title();
   return NULL;
 }
 
@@ -2769,51 +2690,29 @@ static const char *did_set_titlelen(optset_T *args)
   return NULL;
 }
 
-/// Process the new 'cmdheight' option value.
-static const char *did_set_cmdheight(optset_T *args)
-{
-  OptInt old_value = args->os_oldval.number;
-
-  if (ui_has(kUIMessages)) {
-    p_ch = 0;
-  }
-  if (p_ch > Rows - min_rows() + 1) {
-    p_ch = Rows - min_rows() + 1;
-  }
-
-  // if p_ch changed value, change the command line height
-  // Only compute the new window layout when startup has been
-  // completed. Otherwise the frame sizes may be wrong.
-  if ((p_ch != old_value
-       || tabline_height() + global_stl_height() + topframe->fr_height != Rows - p_ch)
-      && full_screen) {
-    command_height();
-  }
-
-  return NULL;
-}
-
-/// Process the new 'updatecount' option value.
-static const char *did_set_updatecount(optset_T *args)
+/// Process the updated 'undofile' option value.
+static const char *did_set_undofile(optset_T *args)
 {
-  OptInt old_value = args->os_oldval.number;
-
-  // when 'updatecount' changes from zero to non-zero, open swap files
-  if (p_uc && !old_value) {
-    ml_open_files();
+  // Only take action when the option was set.
+  if (!curbuf->b_p_udf && !p_udf) {
+    return NULL;
   }
 
-  return NULL;
-}
+  // When reset we do not delete the undo file, the option may be set again
+  // without making any changes in between.
+  uint8_t hash[UNDO_HASH_SIZE];
 
-/// Process the new 'pumblend' option value.
-static const char *did_set_pumblend(optset_T *args FUNC_ATTR_UNUSED)
-{
-  p_pb = MAX(MIN(p_pb, 100), 0);
-  hl_invalidate_blends();
-  pum_grid.blending = (p_pb > 0);
-  if (pum_drawn()) {
-    pum_redraw();
+  FOR_ALL_BUFFERS(bp) {
+    // When 'undofile' is set globally: for every buffer, otherwise
+    // only for the current buffer: Try to read in the undofile,
+    // if one exists, the buffer wasn't changed and the buffer was
+    // loaded
+    if ((curbuf == bp
+         || (args->os_flags & OPT_GLOBAL) || args->os_flags == 0)
+        && !bufIsChanged(bp) && bp->b_ml.ml_mfp != NULL) {
+      u_compute_hash(bp, hash);
+      u_read_undo(NULL, hash, bp->b_fname);
+    }
   }
 
   return NULL;
@@ -2840,34 +2739,29 @@ const char *did_set_buflocal_undolevels(buf_T *buf, OptInt value, OptInt old_val
   return NULL;
 }
 
-/// Process the new 'scrollback' option value.
-static const char *did_set_scrollback(optset_T *args)
+/// Process the new 'undolevels' option value.
+static const char *did_set_undolevels(optset_T *args)
 {
   buf_T *buf = (buf_T *)args->os_buf;
-  OptInt old_value = args->os_oldval.number;
-  OptInt value = args->os_newval.number;
+  OptInt *pp = (OptInt *)args->os_varp;
 
-  if (buf->terminal && value < old_value) {
-    // Force the scrollback to take immediate effect only when decreasing it.
-    on_scrollback_option_changed(buf->terminal);
+  if (pp == &p_ul) {                  // global 'undolevels'
+    did_set_global_undolevels(args->os_newval.number, args->os_oldval.number);
+  } else if (pp == &curbuf->b_p_ul) {      // buffer local 'undolevels'
+    did_set_buflocal_undolevels(buf, args->os_newval.number, args->os_oldval.number);
   }
-  return NULL;
-}
-
-/// Process the new 'numberwidth' option value.
-static const char *did_set_numberwidth(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  win->w_nrwidth_line_count = 0;  // trigger a redraw
 
   return NULL;
 }
 
-/// Process the new 'textwidth' option value.
-static const char *did_set_textwidth(optset_T *args FUNC_ATTR_UNUSED)
+/// Process the new 'updatecount' option value.
+static const char *did_set_updatecount(optset_T *args)
 {
-  FOR_ALL_TAB_WINDOWS(tp, wp) {
-    check_colorcolumn(wp);
+  OptInt old_value = args->os_oldval.number;
+
+  // when 'updatecount' changes from zero to non-zero, open swap files
+  if (p_uc && !old_value) {
+    ml_open_files();
   }
 
   return NULL;
@@ -2889,21 +2783,143 @@ static const char *did_set_winblend(optset_T *args)
   return NULL;
 }
 
-/// Process the new 'undolevels' option value.
-static const char *did_set_undolevels(optset_T *args)
+/// Process the new 'window' option value.
+static const char *did_set_window(optset_T *args FUNC_ATTR_UNUSED)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
-  OptInt *pp = (OptInt *)args->os_varp;
+  if (p_window < 1) {
+    p_window = Rows - 1;
+  } else if (p_window >= Rows) {
+    p_window = Rows - 1;
+  }
+  return NULL;
+}
 
-  if (pp == &p_ul) {                  // global 'undolevels'
-    did_set_global_undolevels(args->os_newval.number, args->os_oldval.number);
-  } else if (pp == &curbuf->b_p_ul) {      // buffer local 'undolevels'
-    did_set_buflocal_undolevels(buf, args->os_newval.number, args->os_oldval.number);
+/// Process the new 'winheight' value.
+static const char *did_set_winheight(optset_T *args)
+{
+  // Change window height NOW
+  if (!ONE_WINDOW) {
+    win_T *win = (win_T *)args->os_win;
+    if (win->w_height < p_wh) {
+      win_setheight((int)p_wh);
+    }
   }
 
   return NULL;
 }
 
+/// Process the new 'winwidth' option value.
+static const char *did_set_winwidth(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+
+  if (!ONE_WINDOW && win->w_width < p_wiw) {
+    win_setwidth((int)p_wiw);
+  }
+  return NULL;
+}
+
+/// Process the updated 'wrap' option value.
+static const char *did_set_wrap(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+
+  // If 'wrap' is set, set w_leftcol to zero.
+  if (win->w_p_wrap) {
+    win->w_leftcol = 0;
+  }
+  return NULL;
+}
+
+/// Set the value of a boolean option, taking care of side effects
+///
+/// @param[in]  opt_idx  Option index in options[] table.
+/// @param[out]  varp  Pointer to the option variable.
+/// @param[in]  value  New value.
+/// @param[in]  opt_flags  OPT_LOCAL and/or OPT_GLOBAL.
+///
+/// @return NULL on success, error message on error.
+static const char *set_bool_option(const int opt_idx, char *const varp, const int value,
+                                   const int opt_flags)
+{
+  int old_value = *(int *)varp;
+  int old_global_value = 0;
+
+  // Disallow changing some options from secure mode
+  if ((secure || sandbox != 0)
+      && (options[opt_idx].flags & P_SECURE)) {
+    return e_secure;
+  }
+
+  // Save the global value before changing anything. This is needed as for
+  // a global-only option setting the "local value" in fact sets the global
+  // value (since there is only one value).
+  if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0) {
+    old_global_value = *(int *)get_varp_scope(&(options[opt_idx]), OPT_GLOBAL);
+  }
+
+  *(int *)varp = value;             // set the new value
+  // Remember where the option was set.
+  set_option_sctx_idx(opt_idx, opt_flags, current_sctx);
+
+  // May set global value for local option.
+  if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0) {
+    *(int *)get_varp_scope(&(options[opt_idx]), OPT_GLOBAL) = value;
+  }
+
+  // Handle side effects for changing a bool option.
+  const char *errmsg = NULL;
+  bool doskip = false;
+  if ((int *)varp == &p_force_on) {
+    errmsg = did_set_force_on(&doskip);
+  } else if ((int *)varp == &p_force_off) {
+    errmsg = did_set_force_off(&doskip);
+  } else if (options[opt_idx].opt_did_set_cb != NULL) {
+    optset_T args = {
+      .os_varp = varp,
+      .os_flags = opt_flags,
+      .os_oldval.boolean = old_value,
+      .os_newval.boolean = value,
+      .os_doskip = false,
+      .os_errbuf = NULL,
+      .os_errbuflen = 0,
+      .os_buf = curbuf,
+      .os_win = curwin
+    };
+
+    errmsg = options[opt_idx].opt_did_set_cb(&args);
+    doskip = args.os_doskip;
+  }
+  if (doskip) {
+    return errmsg;
+  }
+
+  // after handling side effects, call autocommand
+
+  options[opt_idx].flags |= P_WAS_SET;
+
+  apply_optionset_autocmd(opt_idx, opt_flags,
+                          (long)(old_value ? true : false),
+                          (long)(old_global_value ? true : false),
+                          (long)(value ? true : false), NULL);
+
+  if (options[opt_idx].flags & P_UI_OPTION) {
+    ui_call_option_set(cstr_as_string(options[opt_idx].fullname),
+                       BOOLEAN_OBJ(*varp));
+  }
+  if ((int *)varp == &p_ru || (int *)varp == &p_sc) {
+    // in case 'ruler' or 'showcmd' changed
+    comp_col();
+  }
+  if (curwin->w_curswant != MAXCOL
+      && (options[opt_idx].flags & (P_CURSWANT | P_RALL)) != 0) {
+    curwin->w_set_curswant = true;
+  }
+  check_redraw(options[opt_idx].flags);
+
+  return errmsg;
+}
+
 /// Check the bounds of numeric options.
 static const char *check_num_option_bounds(OptInt *pp, OptInt old_value, long old_Rows,
                                            char *errbuf, size_t errbuflen, const char *errmsg)
@@ -5744,22 +5760,6 @@ void reset_option_was_set(const char *name)
   options[idx].flags &= ~P_WAS_SET;
 }
 
-/// Called when the 'breakat' option changes value.
-static const char *did_set_breakat(optset_T *args FUNC_ATTR_UNUSED)
-{
-  for (int i = 0; i < 256; i++) {
-    breakat_flags[i] = false;
-  }
-
-  if (p_breakat != NULL) {
-    for (char *p = p_breakat; *p; p++) {
-      breakat_flags[(uint8_t)(*p)] = true;
-    }
-  }
-
-  return NULL;
-}
-
 /// fill_culopt_flags() -- called when 'culopt' changes value
 int fill_culopt_flags(char *val, win_T *wp)
 {
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
@@ -519,71 +519,6 @@ static bool valid_filetype(const char *val)
   return valid_name(val, ".-_");
 }
 
-/// Handle setting 'mousescroll'.
-/// @return error message, NULL if it's OK.
-const char *did_set_mousescroll(optset_T *args FUNC_ATTR_UNUSED)
-{
-  OptInt vertical = -1;
-  OptInt horizontal = -1;
-
-  char *string = p_mousescroll;
-
-  while (true) {
-    char *end = vim_strchr(string, ',');
-    size_t length = end ? (size_t)(end - string) : strlen(string);
-
-    // Both "ver:" and "hor:" are 4 bytes long.
-    // They should be followed by at least one digit.
-    if (length <= 4) {
-      return e_invarg;
-    }
-
-    OptInt *direction;
-
-    if (memcmp(string, "ver:", 4) == 0) {
-      direction = &vertical;
-    } else if (memcmp(string, "hor:", 4) == 0) {
-      direction = &horizontal;
-    } else {
-      return e_invarg;
-    }
-
-    // If the direction has already been set, this is a duplicate.
-    if (*direction != -1) {
-      return e_invarg;
-    }
-
-    // Verify that only digits follow the colon.
-    for (size_t i = 4; i < length; i++) {
-      if (!ascii_isdigit(string[i])) {
-        return N_("E5080: Digit expected");
-      }
-    }
-
-    string += 4;
-    *direction = getdigits_int(&string, false, -1);
-
-    // Num options are generally kept within the signed int range.
-    // We know this number won't be negative because we've already checked for
-    // a minus sign. We'll allow 0 as a means of disabling mouse scrolling.
-    if (*direction == -1) {
-      return e_invarg;
-    }
-
-    if (!end) {
-      break;
-    }
-
-    string = end + 1;
-  }
-
-  // If a direction wasn't set, fallback to the default value.
-  p_mousescroll_vert = (vertical == -1) ? MOUSESCROLL_VERT_DFLT : vertical;
-  p_mousescroll_hor = (horizontal == -1) ? MOUSESCROLL_HOR_DFLT : horizontal;
-
-  return NULL;
-}
-
 /// Handle setting 'signcolumn' for value 'val'
 ///
 /// @return OK when the value is valid, FAIL otherwise
@@ -695,6 +630,81 @@ static bool check_illegal_path_names(char *val, uint32_t flags)
               && strpbrk(val, "*?[|;&<>\r\n") != NULL));
 }
 
+/// An option that accepts a list of flags is changed.
+/// e.g. 'viewoptions', 'switchbuf', 'casemap', etc.
+static const char *did_set_opt_flags(char *val, char **values, unsigned *flagp, bool list)
+{
+  if (opt_strings_flags(val, values, flagp, list) != OK) {
+    return e_invarg;
+  }
+  return NULL;
+}
+
+/// An option that accepts a list of string values is changed.
+/// e.g. 'nrformats', 'scrollopt', 'wildoptions', etc.
+static const char *did_set_opt_strings(char *val, char **values, bool list)
+{
+  return did_set_opt_flags(val, values, NULL, list);
+}
+
+/// An option which is a list of flags is set.  Valid values are in "flags".
+static const char *did_set_option_listflag(char *val, char *flags, char *errbuf, size_t errbuflen)
+{
+  for (char *s = val; *s; s++) {
+    if (vim_strchr(flags, (uint8_t)(*s)) == NULL) {
+      return illegal_char(errbuf, errbuflen, (uint8_t)(*s));
+    }
+  }
+
+  return NULL;
+}
+
+/// The 'ambiwidth' option is changed.
+const char *did_set_ambiwidth(optset_T *args FUNC_ATTR_UNUSED)
+{
+  if (check_opt_strings(p_ambw, p_ambw_values, false) != OK) {
+    return e_invarg;
+  }
+  return check_chars_options();
+}
+
+/// The 'background' option is changed.
+const char *did_set_background(optset_T *args FUNC_ATTR_UNUSED)
+{
+  if (check_opt_strings(p_bg, p_bg_values, false) != OK) {
+    return e_invarg;
+  }
+
+  int dark = (*p_bg == 'd');
+
+  init_highlight(false, false);
+
+  if (dark != (*p_bg == 'd') && get_var_value("g:colors_name") != NULL) {
+    // The color scheme must have set 'background' back to another
+    // value, that's not what we want here.  Disable the color
+    // scheme and set the colors again.
+    do_unlet(S_LEN("g:colors_name"), true);
+    free_string_option(p_bg);
+    p_bg = xstrdup((dark ? "dark" : "light"));
+    check_string_option(&p_bg);
+    init_highlight(false, false);
+  }
+  return NULL;
+}
+
+/// The 'backspace' option is changed.
+const char *did_set_backspace(optset_T *args FUNC_ATTR_UNUSED)
+{
+  if (ascii_isdigit(*p_bs)) {
+    if (*p_bs != '2') {
+      return e_invarg;
+    }
+  } else if (check_opt_strings(p_bs, p_bs_values, true) != OK) {
+    return e_invarg;
+  }
+  return NULL;
+}
+
 /// The 'backupcopy' option is changed.
 const char *did_set_backupcopy(optset_T *args)
 {
@@ -746,12 +756,6 @@ const char *did_set_belloff(optset_T *args FUNC_ATTR_UNUSED)
   return did_set_opt_flags(p_bo, p_bo_values, &bo_flags, true);
 }
 
-/// The 'termpastefilter' option is changed.
-const char *did_set_termpastefilter(optset_T *args FUNC_ATTR_UNUSED)
-{
-  return did_set_opt_flags(p_tpf, p_tpf_values, &tpf_flags, true);
-}
-
 /// The 'breakindentopt' option is changed.
 const char *did_set_breakindentopt(optset_T *args)
 {
@@ -767,160 +771,236 @@ const char *did_set_breakindentopt(optset_T *args)
   return NULL;
 }
 
-/// The 'isident' or the 'iskeyword' or the 'isprint' or the 'isfname' option is
-/// changed.
-const char *did_set_isopt(optset_T *args)
+/// The 'bufhidden' option is changed.
+const char *did_set_bufhidden(optset_T *args)
 {
   buf_T *buf = (buf_T *)args->os_buf;
-  // 'isident', 'iskeyword', 'isprint or 'isfname' option: refill g_chartab[]
-  // If the new option is invalid, use old value.
-  // 'lisp' option: refill g_chartab[] for '-' char
-  if (buf_init_chartab(buf, true) == FAIL) {
-    args->os_restore_chartab = true;  // need to restore it below
-    return e_invarg;                  // error in value
-  }
-  return NULL;
+  return did_set_opt_strings(buf->b_p_bh, p_bufhidden_values, false);
 }
 
-/// The 'helpfile' option is changed.
-const char *did_set_helpfile(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'buftype' option is changed.
+const char *did_set_buftype(optset_T *args)
 {
-  // May compute new values for $VIM and $VIMRUNTIME
-  if (didset_vim) {
-    vim_unsetenv_ext("VIM");
+  buf_T *buf = (buf_T *)args->os_buf;
+  win_T *win = (win_T *)args->os_win;
+  // When 'buftype' is set, check for valid value.
+  if ((buf->terminal && buf->b_p_bt[0] != 't')
+      || (!buf->terminal && buf->b_p_bt[0] == 't')
+      || check_opt_strings(buf->b_p_bt, p_buftype_values, false) != OK) {
+    return e_invarg;
   }
-  if (didset_vimruntime) {
-    vim_unsetenv_ext("VIMRUNTIME");
+  if (win->w_status_height || global_stl_height()) {
+    win->w_redr_status = true;
+    redraw_later(win, UPD_VALID);
   }
+  buf->b_help = (buf->b_p_bt[0] == 'h');
+  redraw_titles();
   return NULL;
 }
 
-/// The 'cursorlineopt' option is changed.
-const char *did_set_cursorlineopt(optset_T *args)
+/// The 'casemap' option is changed.
+const char *did_set_casemap(optset_T *args FUNC_ATTR_UNUSED)
 {
-  win_T *win = (win_T *)args->os_win;
-  char **varp = (char **)args->os_varp;
+  return did_set_opt_flags(p_cmp, p_cmp_values, &cmp_flags, true);
+}
 
-  if (**varp == NUL || fill_culopt_flags(*varp, win) != OK) {
-    return e_invarg;
+/// The global 'listchars' or 'fillchars' option is changed.
+static const char *did_set_global_listfillchars(win_T *win, char *val, bool opt_lcs, int opt_flags)
+{
+  const char *errmsg = NULL;
+  char **local_ptr = opt_lcs ? &win->w_p_lcs : &win->w_p_fcs;
+
+  // only apply the global value to "win" when it does not have a
+  // local value
+  if (opt_lcs) {
+    errmsg = set_listchars_option(win, val, **local_ptr == NUL || !(opt_flags & OPT_GLOBAL));
+  } else {
+    errmsg = set_fillchars_option(win, val, **local_ptr == NUL || !(opt_flags & OPT_GLOBAL));
+  }
+  if (errmsg != NULL) {
+    return errmsg;
   }
 
-  return NULL;
-}
+  // If the current window is set to use the global
+  // 'listchars'/'fillchars' value, clear the window-local value.
+  if (!(opt_flags & OPT_GLOBAL)) {
+    clear_string_option(local_ptr);
+  }
 
-/// The 'helplang' option is changed.
-const char *did_set_helplang(optset_T *args FUNC_ATTR_UNUSED)
-{
-  // Check for "", "ab", "ab,cd", etc.
-  for (char *s = p_hlg; *s != NUL; s += 3) {
-    if (s[1] == NUL || ((s[2] != ',' || s[3] == NUL) && s[2] != NUL)) {
-      return e_invarg;
-    }
-    if (s[2] == NUL) {
-      break;
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    // If the current window has a local value need to apply it
+    // again, it was changed when setting the global value.
+    // If no error was returned above, we don't expect an error
+    // here, so ignore the return value.
+    if (opt_lcs) {
+      if (*wp->w_p_lcs == NUL) {
+        (void)set_listchars_option(wp, wp->w_p_lcs, true);
+      }
+    } else {
+      if (*wp->w_p_fcs == NUL) {
+        (void)set_fillchars_option(wp, wp->w_p_fcs, true);
+      }
     }
   }
+
+  redraw_all_later(UPD_NOT_VALID);
+
   return NULL;
 }
 
-/// The 'highlight' option is changed.
-const char *did_set_highlight(optset_T *args)
+/// The 'fillchars' option or the 'listchars' option is changed.
+const char *did_set_chars_option(optset_T *args)
 {
+  win_T *win = (win_T *)args->os_win;
   char **varp = (char **)args->os_varp;
+  const char *errmsg = NULL;
 
-  if (strcmp(*varp, HIGHLIGHT_INIT) != 0) {
-    return e_unsupportedoption;
+  if (varp == &p_lcs      // global 'listchars'
+      || varp == &p_fcs) {  // global 'fillchars'
+    errmsg = did_set_global_listfillchars(win, *varp, varp == &p_lcs, args->os_flags);
+  } else if (varp == &win->w_p_lcs) {  // local 'listchars'
+    errmsg = set_listchars_option(win, *varp, true);
+  } else if (varp == &win->w_p_fcs) {  // local 'fillchars'
+    errmsg = set_fillchars_option(win, *varp, true);
   }
-  return NULL;
+
+  return errmsg;
 }
 
-static const char *did_set_opt_flags(char *val, char **values, unsigned *flagp, bool list)
+/// The 'cinoptions' option is changed.
+const char *did_set_cinoptions(optset_T *args FUNC_ATTR_UNUSED)
 {
-  if (opt_strings_flags(val, values, flagp, list) != OK) {
-    return e_invarg;
-  }
+  // TODO(vim): recognize errors
+  parse_cino(curbuf);
+
   return NULL;
 }
 
-static const char *did_set_opt_strings(char *val, char **values, bool list)
+/// The 'clipboard' option is changed.
+const char *did_set_clipboard(optset_T *args FUNC_ATTR_UNUSED)
 {
-  return did_set_opt_flags(val, values, NULL, list);
+  return did_set_opt_flags(p_cb, p_cb_values, &cb_flags, true);
 }
 
-/// The 'selectmode' option is changed.
-const char *did_set_selectmode(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'colorcolumn' option is changed.
+const char *did_set_colorcolumn(optset_T *args)
 {
-  return did_set_opt_strings(p_slm, p_slm_values, true);
+  win_T *win = (win_T *)args->os_win;
+  return check_colorcolumn(win);
 }
 
-/// The 'inccommand' option is changed.
-const char *did_set_inccommand(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'comments' option is changed.
+const char *did_set_comments(optset_T *args)
 {
-  return did_set_opt_strings(p_icm, p_icm_values, false);
+  char **varp = (char **)args->os_varp;
+  char *errmsg = NULL;
+  for (char *s = *varp; *s;) {
+    while (*s && *s != ':') {
+      if (vim_strchr(COM_ALL, (uint8_t)(*s)) == NULL
+          && !ascii_isdigit(*s) && *s != '-') {
+        errmsg = illegal_char(args->os_errbuf, args->os_errbuflen, (uint8_t)(*s));
+        break;
+      }
+      s++;
+    }
+    if (*s++ == NUL) {
+      errmsg = N_("E524: Missing colon");
+    } else if (*s == ',' || *s == NUL) {
+      errmsg = N_("E525: Zero length string");
+    }
+    if (errmsg != NULL) {
+      break;
+    }
+    while (*s && *s != ',') {
+      if (*s == '\\' && s[1] != NUL) {
+        s++;
+      }
+      s++;
+    }
+    s = skip_to_option_part(s);
+  }
+  return errmsg;
 }
 
-/// The 'sessionoptions' option is changed.
-const char *did_set_sessionoptions(optset_T *args)
+/// The 'commentstring' option is changed.
+const char *did_set_commentstring(optset_T *args)
 {
-  if (opt_strings_flags(p_ssop, p_ssop_values, &ssop_flags, true) != OK) {
-    return e_invarg;
-  }
-  if ((ssop_flags & SSOP_CURDIR) && (ssop_flags & SSOP_SESDIR)) {
-    // Don't allow both "sesdir" and "curdir".
-    const char *oldval = args->os_oldval.string;
-    (void)opt_strings_flags(oldval, p_ssop_values, &ssop_flags, true);
-    return e_invarg;
+  char **varp = (char **)args->os_varp;
+
+  if (**varp != NUL && strstr(*varp, "%s") == NULL) {
+    return N_("E537: 'commentstring' must be empty or contain %s");
   }
   return NULL;
 }
 
-/// The 'ambiwidth' option is changed.
-const char *did_set_ambiwidth(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'complete' option is changed.
+const char *did_set_complete(optset_T *args)
 {
-  if (check_opt_strings(p_ambw, p_ambw_values, false) != OK) {
-    return e_invarg;
+  char **varp = (char **)args->os_varp;
+
+  // check if it is a valid value for 'complete' -- Acevedo
+  for (char *s = *varp; *s;) {
+    while (*s == ',' || *s == ' ') {
+      s++;
+    }
+    if (!*s) {
+      break;
+    }
+    if (vim_strchr(".wbuksid]tU", (uint8_t)(*s)) == NULL) {
+      return illegal_char(args->os_errbuf, args->os_errbuflen, (uint8_t)(*s));
+    }
+    if (*++s != NUL && *s != ',' && *s != ' ') {
+      if (s[-1] == 'k' || s[-1] == 's') {
+        // skip optional filename after 'k' and 's'
+        while (*s && *s != ',' && *s != ' ') {
+          if (*s == '\\' && s[1] != NUL) {
+            s++;
+          }
+          s++;
+        }
+      } else {
+        if (args->os_errbuf != NULL) {
+          vim_snprintf(args->os_errbuf, args->os_errbuflen,
+                       _("E535: Illegal character after <%c>"),
+                       *--s);
+          return args->os_errbuf;
+        }
+        return "";
+      }
+    }
   }
-  return check_chars_options();
+  return NULL;
 }
 
-/// The 'background' option is changed.
-const char *did_set_background(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'completeopt' option is changed.
+const char *did_set_completeopt(optset_T *args FUNC_ATTR_UNUSED)
 {
-  if (check_opt_strings(p_bg, p_bg_values, false) != OK) {
+  if (check_opt_strings(p_cot, p_cot_values, true) != OK) {
     return e_invarg;
   }
-
-  int dark = (*p_bg == 'd');
-
-  init_highlight(false, false);
-
-  if (dark != (*p_bg == 'd') && get_var_value("g:colors_name") != NULL) {
-    // The color scheme must have set 'background' back to another
-    // value, that's not what we want here.  Disable the color
-    // scheme and set the colors again.
-    do_unlet(S_LEN("g:colors_name"), true);
-    free_string_option(p_bg);
-    p_bg = xstrdup((dark ? "dark" : "light"));
-    check_string_option(&p_bg);
-    init_highlight(false, false);
-  }
+  completeopt_was_set();
   return NULL;
 }
 
-/// The 'whichwrap' option is changed.
-const char *did_set_whichwrap(optset_T *args)
+#ifdef BACKSLASH_IN_FILENAME
+/// The 'completeslash' option is changed.
+const char *did_set_completeslash(optset_T *args)
 {
-  char **varp = (char **)args->os_varp;
-
-  return did_set_option_listflag(*varp, WW_ALL, args->os_errbuf, args->os_errbuflen);
+  buf_T *buf = (buf_T *)args->os_buf;
+  if (check_opt_strings(p_csl, p_csl_values, false) != OK
+      || check_opt_strings(buf->b_p_csl, p_csl_values, false) != OK) {
+    return e_invarg;
+  }
+  return NULL;
 }
+#endif
 
-/// The 'shortmess' option is changed.
-const char *did_set_shortmess(optset_T *args)
+/// The 'concealcursor' option is changed.
+const char *did_set_concealcursor(optset_T *args)
 {
   char **varp = (char **)args->os_varp;
 
-  return did_set_option_listflag(*varp, SHM_ALL, args->os_errbuf, args->os_errbuflen);
+  return did_set_option_listflag(*varp, COCU_ALL, args->os_errbuf, args->os_errbuflen);
 }
 
 /// The 'cpoptions' option is changed.
@@ -931,66 +1011,42 @@ const char *did_set_cpoptions(optset_T *args)
   return did_set_option_listflag(*varp, CPO_VI, args->os_errbuf, args->os_errbuflen);
 }
 
-/// The 'clipboard' option is changed.
-const char *did_set_clipboard(optset_T *args FUNC_ATTR_UNUSED)
-{
-  return did_set_opt_flags(p_cb, p_cb_values, &cb_flags, true);
-}
-
-/// The 'foldopen' option is changed.
-const char *did_set_foldopen(optset_T *args FUNC_ATTR_UNUSED)
-{
-  return did_set_opt_flags(p_fdo, p_fdo_values, &fdo_flags, true);
-}
-
-/// The 'formatoptions' option is changed.
-const char *did_set_formatoptions(optset_T *args)
-{
-  char **varp = (char **)args->os_varp;
-
-  return did_set_option_listflag(*varp, FO_ALL, args->os_errbuf, args->os_errbuflen);
-}
-
-/// The 'concealcursor' option is changed.
-const char *did_set_concealcursor(optset_T *args)
+/// The 'cursorlineopt' option is changed.
+const char *did_set_cursorlineopt(optset_T *args)
 {
+  win_T *win = (win_T *)args->os_win;
   char **varp = (char **)args->os_varp;
 
-  return did_set_option_listflag(*varp, COCU_ALL, args->os_errbuf, args->os_errbuflen);
-}
-
-/// The 'mouse' option is changed.
-const char *did_set_mouse(optset_T *args)
-{
-  char **varp = (char **)args->os_varp;
+  if (**varp == NUL || fill_culopt_flags(*varp, win) != OK) {
+    return e_invarg;
+  }
 
-  return did_set_option_listflag(*varp, MOUSE_ALL, args->os_errbuf, args->os_errbuflen);
+  return NULL;
 }
 
-/// The 'wildmode' option is changed.
-const char *did_set_wildmode(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'debug' option is changed.
+const char *did_set_debug(optset_T *args FUNC_ATTR_UNUSED)
 {
-  if (check_opt_wim() == FAIL) {
-    return e_invarg;
-  }
-  return NULL;
+  return did_set_opt_strings(p_debug, p_debug_values, false);
 }
 
-/// The 'winaltkeys' option is changed.
-const char *did_set_winaltkeys(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'diffopt' option is changed.
+const char *did_set_diffopt(optset_T *args FUNC_ATTR_UNUSED)
 {
-  if (*p_wak == NUL || check_opt_strings(p_wak, p_wak_values, false) != OK) {
+  if (diffopt_changed() == FAIL) {
     return e_invarg;
   }
   return NULL;
 }
 
-/// The 'eventignore' option is changed.
-const char *did_set_eventignore(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'display' option is changed.
+const char *did_set_display(optset_T *args FUNC_ATTR_UNUSED)
 {
-  if (check_ei() == FAIL) {
+  if (opt_strings_flags(p_dy, p_dy_values, &dy_flags, true) != OK) {
     return e_invarg;
   }
+  (void)init_chartab();
+  msg_grid_validate();
   return NULL;
 }
 
@@ -1042,22 +1098,245 @@ const char *did_set_encoding(optset_T *args)
   return NULL;
 }
 
-/// The 'keymap' option has changed.
-const char *did_set_keymap(optset_T *args)
+/// The 'eventignore' option is changed.
+const char *did_set_eventignore(optset_T *args FUNC_ATTR_UNUSED)
+{
+  if (check_ei() == FAIL) {
+    return e_invarg;
+  }
+  return NULL;
+}
+
+/// The 'fileformat' option is changed.
+const char *did_set_fileformat(optset_T *args)
 {
   buf_T *buf = (buf_T *)args->os_buf;
   char **varp = (char **)args->os_varp;
+  const char *oldval = args->os_oldval.string;
   int opt_flags = args->os_flags;
+  if (!MODIFIABLE(buf) && !(opt_flags & OPT_GLOBAL)) {
+    return e_modifiable;
+  } else if (check_opt_strings(*varp, p_ff_values, false) != OK) {
+    return e_invarg;
+  }
+  redraw_titles();
+  // update flag in swap file
+  ml_setflags(buf);
+  // Redraw needed when switching to/from "mac": a CR in the text
+  // will be displayed differently.
+  if (get_fileformat(buf) == EOL_MAC || *oldval == 'm') {
+    redraw_buf_later(buf, UPD_NOT_VALID);
+  }
+  return NULL;
+}
+
+/// The 'fileformats' option is changed.
+const char *did_set_fileformats(optset_T *args)
+{
+  return did_set_opt_strings(p_ffs, p_ff_values, true);
+}
+
+/// The 'filetype' or the 'syntax' option is changed.
+const char *did_set_filetype_or_syntax(optset_T *args)
+{
+  char **varp = (char **)args->os_varp;
 
   if (!valid_filetype(*varp)) {
     return e_invarg;
   }
 
-  int secure_save = secure;
+  args->os_value_changed = strcmp(args->os_oldval.string, *varp) != 0;
 
-  // Reset the secure flag, since the value of 'keymap' has
-  // been checked to be safe.
-  secure = 0;
+  // Since we check the value, there is no need to set P_INSECURE,
+  // even when the value comes from a modeline.
+  args->os_value_checked = true;
+
+  return NULL;
+}
+
+/// The 'foldclose' option is changed.
+const char *did_set_foldclose(optset_T *args FUNC_ATTR_UNUSED)
+{
+  return did_set_opt_strings(p_fcl, p_fcl_values, true);
+}
+
+/// The 'foldcolumn' option is changed.
+const char *did_set_foldcolumn(optset_T *args)
+{
+  char **varp = (char **)args->os_varp;
+  if (**varp == NUL || check_opt_strings(*varp, p_fdc_values, false) != OK) {
+    return e_invarg;
+  }
+  return NULL;
+}
+
+/// The 'foldexpr' option is changed.
+const char *did_set_foldexpr(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+  (void)did_set_optexpr(args);
+  if (foldmethodIsExpr(win)) {
+    foldUpdateAll(win);
+  }
+  return NULL;
+}
+
+/// The 'foldignore' option is changed.
+const char *did_set_foldignore(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+  if (foldmethodIsIndent(win)) {
+    foldUpdateAll(win);
+  }
+  return NULL;
+}
+
+/// The 'foldmarker' option is changed.
+const char *did_set_foldmarker(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+  char **varp = (char **)args->os_varp;
+  char *p = vim_strchr(*varp, ',');
+
+  if (p == NULL) {
+    return e_comma_required;
+  }
+
+  if (p == *varp || p[1] == NUL) {
+    return e_invarg;
+  }
+
+  if (foldmethodIsMarker(win)) {
+    foldUpdateAll(win);
+  }
+
+  return NULL;
+}
+
+/// The 'foldmethod' option is changed.
+const char *did_set_foldmethod(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+  char **varp = (char **)args->os_varp;
+  if (check_opt_strings(*varp, p_fdm_values, false) != OK
+      || *win->w_p_fdm == NUL) {
+    return e_invarg;
+  }
+  foldUpdateAll(win);
+  if (foldmethodIsDiff(win)) {
+    newFoldLevel();
+  }
+  return NULL;
+}
+
+/// The 'foldopen' option is changed.
+const char *did_set_foldopen(optset_T *args FUNC_ATTR_UNUSED)
+{
+  return did_set_opt_flags(p_fdo, p_fdo_values, &fdo_flags, true);
+}
+
+/// The 'formatoptions' option is changed.
+const char *did_set_formatoptions(optset_T *args)
+{
+  char **varp = (char **)args->os_varp;
+
+  return did_set_option_listflag(*varp, FO_ALL, args->os_errbuf, args->os_errbuflen);
+}
+
+/// The 'guicursor' option is changed.
+const char *did_set_guicursor(optset_T *args FUNC_ATTR_UNUSED)
+{
+  return parse_shape_opt(SHAPE_CURSOR);
+}
+
+/// The 'helpfile' option is changed.
+const char *did_set_helpfile(optset_T *args FUNC_ATTR_UNUSED)
+{
+  // May compute new values for $VIM and $VIMRUNTIME
+  if (didset_vim) {
+    vim_unsetenv_ext("VIM");
+  }
+  if (didset_vimruntime) {
+    vim_unsetenv_ext("VIMRUNTIME");
+  }
+  return NULL;
+}
+
+/// The 'helplang' option is changed.
+const char *did_set_helplang(optset_T *args FUNC_ATTR_UNUSED)
+{
+  // Check for "", "ab", "ab,cd", etc.
+  for (char *s = p_hlg; *s != NUL; s += 3) {
+    if (s[1] == NUL || ((s[2] != ',' || s[3] == NUL) && s[2] != NUL)) {
+      return e_invarg;
+    }
+    if (s[2] == NUL) {
+      break;
+    }
+  }
+  return NULL;
+}
+
+/// The 'highlight' option is changed.
+const char *did_set_highlight(optset_T *args)
+{
+  char **varp = (char **)args->os_varp;
+
+  if (strcmp(*varp, HIGHLIGHT_INIT) != 0) {
+    return e_unsupportedoption;
+  }
+  return NULL;
+}
+
+/// The 'iconstring' option is changed.
+const char *did_set_iconstring(optset_T *args)
+{
+  return did_set_titleiconstring(args, STL_IN_ICON);
+}
+
+/// The 'inccommand' option is changed.
+const char *did_set_inccommand(optset_T *args FUNC_ATTR_UNUSED)
+{
+  return did_set_opt_strings(p_icm, p_icm_values, false);
+}
+
+/// The 'isident' or the 'iskeyword' or the 'isprint' or the 'isfname' option is
+/// changed.
+const char *did_set_isopt(optset_T *args)
+{
+  buf_T *buf = (buf_T *)args->os_buf;
+  // 'isident', 'iskeyword', 'isprint or 'isfname' option: refill g_chartab[]
+  // If the new option is invalid, use old value.
+  // 'lisp' option: refill g_chartab[] for '-' char
+  if (buf_init_chartab(buf, true) == FAIL) {
+    args->os_restore_chartab = true;  // need to restore it below
+    return e_invarg;                  // error in value
+  }
+  return NULL;
+}
+
+/// The 'jumpoptions' option is changed.
+const char *did_set_jumpoptions(optset_T *args FUNC_ATTR_UNUSED)
+{
+  return did_set_opt_flags(p_jop, p_jop_values, &jop_flags, true);
+}
+
+/// The 'keymap' option has changed.
+const char *did_set_keymap(optset_T *args)
+{
+  buf_T *buf = (buf_T *)args->os_buf;
+  char **varp = (char **)args->os_varp;
+  int opt_flags = args->os_flags;
+
+  if (!valid_filetype(*varp)) {
+    return e_invarg;
+  }
+
+  int secure_save = secure;
+
+  // Reset the secure flag, since the value of 'keymap' has
+  // been checked to be safe.
+  secure = 0;
 
   // load or unload key mapping tables
   const char *errmsg = keymap_init();
@@ -1094,33 +1373,26 @@ const char *did_set_keymap(optset_T *args)
   return errmsg;
 }
 
-/// The 'fileformat' option is changed.
-const char *did_set_fileformat(optset_T *args)
+/// The 'keymodel' option is changed.
+const char *did_set_keymodel(optset_T *args FUNC_ATTR_UNUSED)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
-  char **varp = (char **)args->os_varp;
-  const char *oldval = args->os_oldval.string;
-  int opt_flags = args->os_flags;
-  if (!MODIFIABLE(buf) && !(opt_flags & OPT_GLOBAL)) {
-    return e_modifiable;
-  } else if (check_opt_strings(*varp, p_ff_values, false) != OK) {
+  if (check_opt_strings(p_km, p_km_values, true) != OK) {
     return e_invarg;
   }
-  redraw_titles();
-  // update flag in swap file
-  ml_setflags(buf);
-  // Redraw needed when switching to/from "mac": a CR in the text
-  // will be displayed differently.
-  if (get_fileformat(buf) == EOL_MAC || *oldval == 'm') {
-    redraw_buf_later(buf, UPD_NOT_VALID);
-  }
+  km_stopsel = (vim_strchr(p_km, 'o') != NULL);
+  km_startsel = (vim_strchr(p_km, 'a') != NULL);
   return NULL;
 }
 
-/// The 'fileformats' option is changed.
-const char *did_set_fileformats(optset_T *args)
+/// The 'lispoptions' option is changed.
+const char *did_set_lispoptions(optset_T *args)
 {
-  return did_set_opt_strings(p_ffs, p_ff_values, true);
+  char **varp = (char **)args->os_varp;
+
+  if (**varp != NUL && strcmp(*varp, "expr:0") != 0 && strcmp(*varp, "expr:1") != 0) {
+    return e_invarg;
+  }
+  return NULL;
 }
 
 /// The 'matchpairs' option is changed.
@@ -1150,433 +1422,135 @@ const char *did_set_matchpairs(optset_T *args)
   return NULL;
 }
 
-/// The 'cinoptions' option is changed.
-const char *did_set_cinoptions(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'mkspellmem' option is changed.
+const char *did_set_mkspellmem(optset_T *args FUNC_ATTR_UNUSED)
 {
-  // TODO(vim): recognize errors
-  parse_cino(curbuf);
-
+  if (spell_check_msm() != OK) {
+    return e_invarg;
+  }
   return NULL;
 }
 
-/// The 'colorcolumn' option is changed.
-const char *did_set_colorcolumn(optset_T *args)
+/// The 'mouse' option is changed.
+const char *did_set_mouse(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
-  return check_colorcolumn(win);
+  char **varp = (char **)args->os_varp;
+
+  return did_set_option_listflag(*varp, MOUSE_ALL, args->os_errbuf, args->os_errbuflen);
 }
 
-const char *did_set_comments(optset_T *args)
+/// The 'mousemodel' option is changed.
+const char *did_set_mousemodel(optset_T *args FUNC_ATTR_UNUSED)
 {
-  char **varp = (char **)args->os_varp;
-  char *errmsg = NULL;
-  for (char *s = *varp; *s;) {
-    while (*s && *s != ':') {
-      if (vim_strchr(COM_ALL, (uint8_t)(*s)) == NULL
-          && !ascii_isdigit(*s) && *s != '-') {
-        errmsg = illegal_char(args->os_errbuf, args->os_errbuflen, (uint8_t)(*s));
-        break;
-      }
-      s++;
-    }
-    if (*s++ == NUL) {
-      errmsg = N_("E524: Missing colon");
-    } else if (*s == ',' || *s == NUL) {
-      errmsg = N_("E525: Zero length string");
-    }
-    if (errmsg != NULL) {
-      break;
-    }
-    while (*s && *s != ',') {
-      if (*s == '\\' && s[1] != NUL) {
-        s++;
-      }
-      s++;
-    }
-    s = skip_to_option_part(s);
-  }
-  return errmsg;
+  return did_set_opt_strings(p_mousem, p_mousem_values, false);
 }
 
-/// The global 'listchars' or 'fillchars' option is changed.
-static const char *did_set_global_listfillchars(win_T *win, char *val, bool opt_lcs, int opt_flags)
+/// Handle setting 'mousescroll'.
+/// @return error message, NULL if it's OK.
+const char *did_set_mousescroll(optset_T *args FUNC_ATTR_UNUSED)
 {
-  const char *errmsg = NULL;
-  char **local_ptr = opt_lcs ? &win->w_p_lcs : &win->w_p_fcs;
+  OptInt vertical = -1;
+  OptInt horizontal = -1;
 
-  // only apply the global value to "win" when it does not have a
-  // local value
-  if (opt_lcs) {
-    errmsg = set_listchars_option(win, val, **local_ptr == NUL || !(opt_flags & OPT_GLOBAL));
-  } else {
-    errmsg = set_fillchars_option(win, val, **local_ptr == NUL || !(opt_flags & OPT_GLOBAL));
-  }
-  if (errmsg != NULL) {
-    return errmsg;
-  }
+  char *string = p_mousescroll;
 
-  // If the current window is set to use the global
-  // 'listchars'/'fillchars' value, clear the window-local value.
-  if (!(opt_flags & OPT_GLOBAL)) {
-    clear_string_option(local_ptr);
-  }
+  while (true) {
+    char *end = vim_strchr(string, ',');
+    size_t length = end ? (size_t)(end - string) : strlen(string);
 
-  FOR_ALL_TAB_WINDOWS(tp, wp) {
-    // If the current window has a local value need to apply it
-    // again, it was changed when setting the global value.
-    // If no error was returned above, we don't expect an error
-    // here, so ignore the return value.
-    if (opt_lcs) {
-      if (*wp->w_p_lcs == NUL) {
-        (void)set_listchars_option(wp, wp->w_p_lcs, true);
-      }
-    } else {
-      if (*wp->w_p_fcs == NUL) {
-        (void)set_fillchars_option(wp, wp->w_p_fcs, true);
-      }
+    // Both "ver:" and "hor:" are 4 bytes long.
+    // They should be followed by at least one digit.
+    if (length <= 4) {
+      return e_invarg;
     }
-  }
-
-  redraw_all_later(UPD_NOT_VALID);
-
-  return NULL;
-}
-
-/// Handle the new value of 'fillchars'.
-const char *set_fillchars_option(win_T *wp, char *val, int apply)
-{
-  return set_chars_option(wp, val, false, apply);
-}
-
-/// Handle the new value of 'listchars'.
-const char *set_listchars_option(win_T *wp, char *val, int apply)
-{
-  return set_chars_option(wp, val, true, apply);
-}
-
-/// The 'fillchars' option or the 'listchars' option is changed.
-const char *did_set_chars_option(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  char **varp = (char **)args->os_varp;
-  const char *errmsg = NULL;
-
-  if (varp == &p_lcs      // global 'listchars'
-      || varp == &p_fcs) {  // global 'fillchars'
-    errmsg = did_set_global_listfillchars(win, *varp, varp == &p_lcs, args->os_flags);
-  } else if (varp == &win->w_p_lcs) {  // local 'listchars'
-    errmsg = set_listchars_option(win, *varp, true);
-  } else if (varp == &win->w_p_fcs) {  // local 'fillchars'
-    errmsg = set_fillchars_option(win, *varp, true);
-  }
-
-  return errmsg;
-}
-
-/// The 'verbosefile' option is changed.
-const char *did_set_verbosefile(optset_T *args)
-{
-  verbose_stop();
-  if (*p_vfile != NUL && verbose_open() == FAIL) {
-    return (char *)e_invarg;
-  }
-  return NULL;
-}
-
-/// The 'viewoptions' option is changed.
-const char *did_set_viewoptions(optset_T *args FUNC_ATTR_UNUSED)
-{
-  return did_set_opt_flags(p_vop, p_ssop_values, &vop_flags, true);
-}
 
-static int shada_idx = -1;
+    OptInt *direction;
 
-static const char *did_set_shada(vimoption_T **opt, int *opt_idx, bool *free_oldval, char *errbuf,
-                                 size_t errbuflen)
-{
-  // TODO(ZyX-I): Remove this code in the future, alongside with &viminfo
-  //              option.
-  *opt_idx = (((*opt)->fullname[0] == 'v')
-              ? (shada_idx == -1 ? ((shada_idx = findoption("shada"))) : shada_idx)
-              : *opt_idx);
-  *opt = get_option(*opt_idx);
-  // Update free_oldval now that we have the opt_idx for 'shada', otherwise
-  // there would be a disconnect between the check for P_ALLOCED at the start
-  // of the function and the set of P_ALLOCED at the end of the function.
-  *free_oldval = ((*opt)->flags & P_ALLOCED);
-  for (char *s = p_shada; *s;) {
-    // Check it's a valid character
-    if (vim_strchr("!\"%'/:<@cfhnrs", (uint8_t)(*s)) == NULL) {
-      return illegal_char(errbuf, errbuflen, (uint8_t)(*s));
+    if (memcmp(string, "ver:", 4) == 0) {
+      direction = &vertical;
+    } else if (memcmp(string, "hor:", 4) == 0) {
+      direction = &horizontal;
+    } else {
+      return e_invarg;
     }
-    if (*s == 'n') {          // name is always last one
-      break;
-    } else if (*s == 'r') {  // skip until next ','
-      while (*++s && *s != ',') {}
-    } else if (*s == '%') {
-      // optional number
-      while (ascii_isdigit(*++s)) {}
-    } else if (*s == '!' || *s == 'h' || *s == 'c') {
-      s++;                    // no extra chars
-    } else {                    // must have a number
-      while (ascii_isdigit(*++s)) {}
 
-      if (!ascii_isdigit(*(s - 1))) {
-        if (errbuf != NULL) {
-          vim_snprintf(errbuf, errbuflen,
-                       _("E526: Missing number after <%s>"),
-                       transchar_byte((uint8_t)(*(s - 1))));
-          return errbuf;
-        } else {
-          return "";
-        }
-      }
+    // If the direction has already been set, this is a duplicate.
+    if (*direction != -1) {
+      return e_invarg;
     }
-    if (*s == ',') {
-      s++;
-    } else if (*s) {
-      if (errbuf != NULL) {
-        return N_("E527: Missing comma");
-      } else {
-        return "";
+
+    // Verify that only digits follow the colon.
+    for (size_t i = 4; i < length; i++) {
+      if (!ascii_isdigit(string[i])) {
+        return N_("E5080: Digit expected");
       }
     }
-  }
-  if (*p_shada && get_shada_parameter('\'') < 0) {
-    return N_("E528: Must specify a ' value");
-  }
-  return NULL;
-}
 
-/// The 'showbreak' option is changed.
-const char *did_set_showbreak(optset_T *args)
-{
-  char **varp = (char **)args->os_varp;
+    string += 4;
+    *direction = getdigits_int(&string, false, -1);
 
-  for (char *s = *varp; *s;) {
-    if (ptr2cells(s) != 1) {
-      return e_showbreak_contains_unprintable_or_wide_character;
+    // Num options are generally kept within the signed int range.
+    // We know this number won't be negative because we've already checked for
+    // a minus sign. We'll allow 0 as a means of disabling mouse scrolling.
+    if (*direction == -1) {
+      return e_invarg;
     }
-    MB_PTR_ADV(s);
-  }
-  return NULL;
-}
 
-/// The 'titlestring' or the 'iconstring' option is changed.
-static const char *did_set_titleiconstring(optset_T *args, int flagval)
-{
-  char **varp = (char **)args->os_varp;
-
-  // NULL => statusline syntax
-  if (vim_strchr(*varp, '%') && check_stl_option(*varp) == NULL) {
-    stl_syntax |= flagval;
-  } else {
-    stl_syntax &= ~flagval;
-  }
-  did_set_title();
-
-  return NULL;
-}
-
-/// The 'titlestring' option is changed.
-const char *did_set_titlestring(optset_T *args)
-{
-  return did_set_titleiconstring(args, STL_IN_TITLE);
-}
-
-/// The 'iconstring' option is changed.
-const char *did_set_iconstring(optset_T *args)
-{
-  return did_set_titleiconstring(args, STL_IN_ICON);
-}
+    if (!end) {
+      break;
+    }
 
-/// The 'selection' option is changed.
-const char *did_set_selection(optset_T *args FUNC_ATTR_UNUSED)
-{
-  if (*p_sel == NUL || check_opt_strings(p_sel, p_sel_values, false) != OK) {
-    return e_invarg;
+    string = end + 1;
   }
-  return NULL;
-}
 
-/// The 'keymodel' option is changed.
-const char *did_set_keymodel(optset_T *args FUNC_ATTR_UNUSED)
-{
-  if (check_opt_strings(p_km, p_km_values, true) != OK) {
-    return e_invarg;
-  }
-  km_stopsel = (vim_strchr(p_km, 'o') != NULL);
-  km_startsel = (vim_strchr(p_km, 'a') != NULL);
-  return NULL;
-}
+  // If a direction wasn't set, fallback to the default value.
+  p_mousescroll_vert = (vertical == -1) ? MOUSESCROLL_VERT_DFLT : vertical;
+  p_mousescroll_hor = (horizontal == -1) ? MOUSESCROLL_HOR_DFLT : horizontal;
 
-/// The 'display' option is changed.
-const char *did_set_display(optset_T *args FUNC_ATTR_UNUSED)
-{
-  if (opt_strings_flags(p_dy, p_dy_values, &dy_flags, true) != OK) {
-    return e_invarg;
-  }
-  (void)init_chartab();
-  msg_grid_validate();
   return NULL;
 }
 
-/// The 'spellfile' option is changed.
-const char *did_set_spellfile(optset_T *args)
+/// The 'nrformats' option is changed.
+const char *did_set_nrformats(optset_T *args)
 {
   char **varp = (char **)args->os_varp;
 
-  // When there is a window for this buffer in which 'spell'
-  // is set load the wordlists.
-  if ((!valid_spellfile(*varp))) {
-    return e_invarg;
-  }
-  return did_set_spell_option(true);
+  return did_set_opt_strings(*varp, p_nf_values, true);
 }
 
-const char *did_set_spelllang(optset_T *args)
+/// One of the '*expr' options is changed:, 'diffexpr', 'foldexpr', 'foldtext',
+/// 'formatexpr', 'includeexpr', 'indentexpr', 'patchexpr' and 'charconvert'.
+const char *did_set_optexpr(optset_T *args)
 {
   char **varp = (char **)args->os_varp;
 
-  // When there is a window for this buffer in which 'spell'
-  // is set load the wordlists.
-  if (!valid_spelllang(*varp)) {
-    return e_invarg;
-  }
-  return did_set_spell_option(false);
-}
-
-/// The 'spellcapcheck' option is changed.
-const char *did_set_spellcapcheck(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  // When 'spellcapcheck' is set compile the regexp program.
-  return compile_cap_prog(win->w_s);
-}
-
-/// The 'spelloptions' option is changed.
-const char *did_set_spelloptions(optset_T *args)
-{
-  win_T *win = (win_T *)args->os_win;
-  if (opt_strings_flags(win->w_s->b_p_spo, p_spo_values, &(win->w_s->b_p_spo_flags),
-                        true) != OK) {
-    return e_invarg;
-  }
-  return NULL;
-}
-
-/// The 'spellsuggest' option is changed.
-const char *did_set_spellsuggest(optset_T *args FUNC_ATTR_UNUSED)
-{
-  if (spell_check_sps() != OK) {
-    return e_invarg;
-  }
-  return NULL;
-}
-
-/// The 'splitkeep' option is changed.
-const char *did_set_splitkeep(optset_T *args FUNC_ATTR_UNUSED)
-{
-  return did_set_opt_strings(p_spk, p_spk_values, false);
-}
-
-/// The 'mkspellmem' option is changed.
-const char *did_set_mkspellmem(optset_T *args FUNC_ATTR_UNUSED)
-{
-  if (spell_check_msm() != OK) {
-    return e_invarg;
-  }
-  return NULL;
-}
-
-/// The 'mousemodel' option is changed.
-const char *did_set_mousemodel(optset_T *args FUNC_ATTR_UNUSED)
-{
-  return did_set_opt_strings(p_mousem, p_mousem_values, false);
-}
-
-/// The 'bufhidden' option is changed.
-const char *did_set_bufhidden(optset_T *args)
-{
-  buf_T *buf = (buf_T *)args->os_buf;
-  return did_set_opt_strings(buf->b_p_bh, p_bufhidden_values, false);
-}
-
-/// The 'buftype' option is changed.
-const char *did_set_buftype(optset_T *args)
-{
-  buf_T *buf = (buf_T *)args->os_buf;
-  win_T *win = (win_T *)args->os_win;
-  // When 'buftype' is set, check for valid value.
-  if ((buf->terminal && buf->b_p_bt[0] != 't')
-      || (!buf->terminal && buf->b_p_bt[0] == 't')
-      || check_opt_strings(buf->b_p_bt, p_buftype_values, false) != OK) {
-    return e_invarg;
-  }
-  if (win->w_status_height || global_stl_height()) {
-    win->w_redr_status = true;
-    redraw_later(win, UPD_VALID);
+  // If the option value starts with <SID> or s:, then replace that with
+  // the script identifier.
+  char *name = get_scriptlocal_funcname(*varp);
+  if (name != NULL) {
+    free_string_option(*varp);
+    *varp = name;
   }
-  buf->b_help = (buf->b_p_bt[0] == 'h');
-  redraw_titles();
   return NULL;
 }
 
-/// The 'casemap' option is changed.
-const char *did_set_casemap(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'redrawdebug' option is changed.
+const char *did_set_redrawdebug(optset_T *args FUNC_ATTR_UNUSED)
 {
-  return did_set_opt_flags(p_cmp, p_cmp_values, &cmp_flags, true);
+  return did_set_opt_flags(p_rdb, p_rdb_values, &rdb_flags, true);
 }
 
-/// The 'statusline', 'winbar', 'tabline', 'rulerformat' or 'statuscolumn' option is changed.
-///
-/// @param rulerformat  true if the 'rulerformat' option is changed
-/// @param statuscolumn  true if the 'statuscolumn' option is changed
-static const char *did_set_statustabline_rulerformat(optset_T *args, bool rulerformat,
-                                                     bool statuscolumn)
+/// The 'rightleftcmd' option is changed.
+const char *did_set_rightleftcmd(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
   char **varp = (char **)args->os_varp;
-  if (rulerformat) {       // reset ru_wid first
-    ru_wid = 0;
-  } else if (statuscolumn) {
-    // reset 'statuscolumn' width
-    win->w_nrwidth_line_count = 0;
-  }
-  const char *errmsg = NULL;
-  char *s = *varp;
-  if (rulerformat && *s == '%') {
-    // set ru_wid if 'ruf' starts with "%99("
-    if (*++s == '-') {        // ignore a '-'
-      s++;
-    }
-    int wid = getdigits_int(&s, true, 0);
-    if (wid && *s == '(' && (errmsg = check_stl_option(p_ruf)) == NULL) {
-      ru_wid = wid;
-    } else {
-      errmsg = check_stl_option(p_ruf);
-    }
-  } else if (rulerformat || s[0] != '%' || s[1] != '!') {
-    // check 'statusline', 'winbar', 'tabline' or 'statuscolumn'
-    // only if it doesn't start with "%!"
-    errmsg = check_stl_option(s);
-  }
-  if (rulerformat && errmsg == NULL) {
-    comp_col();
-  }
-  return errmsg;
-}
 
-/// The 'statusline' option is changed.
-const char *did_set_statusline(optset_T *args)
-{
-  return did_set_statustabline_rulerformat(args, false, false);
-}
-
-/// The 'tabline' option is changed.
-const char *did_set_tabline(optset_T *args)
-{
-  return did_set_statustabline_rulerformat(args, false, false);
+  // Currently only "search" is a supported value.
+  if (**varp != NUL && strcmp(*varp, "search") != 0) {
+    return e_invarg;
+  }
+
+  return NULL;
 }
 
 /// The 'rulerformat' option is changed.
@@ -1585,85 +1559,121 @@ const char *did_set_rulerformat(optset_T *args)
   return did_set_statustabline_rulerformat(args, true, false);
 }
 
-/// The 'winbar' option is changed.
-const char *did_set_winbar(optset_T *args)
+/// The 'scrollopt' option is changed.
+const char *did_set_scrollopt(optset_T *args FUNC_ATTR_UNUSED)
 {
-  return did_set_statustabline_rulerformat(args, false, false);
+  return did_set_opt_strings(p_sbo, p_scbopt_values, true);
 }
 
-/// The 'statuscolumn' option is changed.
-const char *did_set_statuscolumn(optset_T *args)
+/// The 'selection' option is changed.
+const char *did_set_selection(optset_T *args FUNC_ATTR_UNUSED)
 {
-  return did_set_statustabline_rulerformat(args, false, true);
+  if (*p_sel == NUL || check_opt_strings(p_sel, p_sel_values, false) != OK) {
+    return e_invarg;
+  }
+  return NULL;
 }
 
-/// The 'scrollopt' option is changed.
-const char *did_set_scrollopt(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'selectmode' option is changed.
+const char *did_set_selectmode(optset_T *args FUNC_ATTR_UNUSED)
 {
-  return did_set_opt_strings(p_sbo, p_scbopt_values, true);
+  return did_set_opt_strings(p_slm, p_slm_values, true);
 }
 
-/// The 'complete' option is changed.
-const char *did_set_complete(optset_T *args)
+/// The 'sessionoptions' option is changed.
+const char *did_set_sessionoptions(optset_T *args)
 {
-  char **varp = (char **)args->os_varp;
+  if (opt_strings_flags(p_ssop, p_ssop_values, &ssop_flags, true) != OK) {
+    return e_invarg;
+  }
+  if ((ssop_flags & SSOP_CURDIR) && (ssop_flags & SSOP_SESDIR)) {
+    // Don't allow both "sesdir" and "curdir".
+    const char *oldval = args->os_oldval.string;
+    (void)opt_strings_flags(oldval, p_ssop_values, &ssop_flags, true);
+    return e_invarg;
+  }
+  return NULL;
+}
 
-  // check if it is a valid value for 'complete' -- Acevedo
-  for (char *s = *varp; *s;) {
-    while (*s == ',' || *s == ' ') {
-      s++;
+static const char *did_set_shada(vimoption_T **opt, int *opt_idx, bool *free_oldval, char *errbuf,
+                                 size_t errbuflen)
+{
+  static int shada_idx = -1;
+  // TODO(ZyX-I): Remove this code in the future, alongside with &viminfo
+  //              option.
+  *opt_idx = (((*opt)->fullname[0] == 'v')
+              ? (shada_idx == -1 ? ((shada_idx = findoption("shada"))) : shada_idx)
+              : *opt_idx);
+  *opt = get_option(*opt_idx);
+  // Update free_oldval now that we have the opt_idx for 'shada', otherwise
+  // there would be a disconnect between the check for P_ALLOCED at the start
+  // of the function and the set of P_ALLOCED at the end of the function.
+  *free_oldval = ((*opt)->flags & P_ALLOCED);
+  for (char *s = p_shada; *s;) {
+    // Check it's a valid character
+    if (vim_strchr("!\"%'/:<@cfhnrs", (uint8_t)(*s)) == NULL) {
+      return illegal_char(errbuf, errbuflen, (uint8_t)(*s));
     }
-    if (!*s) {
+    if (*s == 'n') {          // name is always last one
       break;
-    }
-    if (vim_strchr(".wbuksid]tU", (uint8_t)(*s)) == NULL) {
-      return illegal_char(args->os_errbuf, args->os_errbuflen, (uint8_t)(*s));
-    }
-    if (*++s != NUL && *s != ',' && *s != ' ') {
-      if (s[-1] == 'k' || s[-1] == 's') {
-        // skip optional filename after 'k' and 's'
-        while (*s && *s != ',' && *s != ' ') {
-          if (*s == '\\' && s[1] != NUL) {
-            s++;
-          }
-          s++;
+    } else if (*s == 'r') {  // skip until next ','
+      while (*++s && *s != ',') {}
+    } else if (*s == '%') {
+      // optional number
+      while (ascii_isdigit(*++s)) {}
+    } else if (*s == '!' || *s == 'h' || *s == 'c') {
+      s++;                    // no extra chars
+    } else {                    // must have a number
+      while (ascii_isdigit(*++s)) {}
+
+      if (!ascii_isdigit(*(s - 1))) {
+        if (errbuf != NULL) {
+          vim_snprintf(errbuf, errbuflen,
+                       _("E526: Missing number after <%s>"),
+                       transchar_byte((uint8_t)(*(s - 1))));
+          return errbuf;
+        } else {
+          return "";
         }
+      }
+    }
+    if (*s == ',') {
+      s++;
+    } else if (*s) {
+      if (errbuf != NULL) {
+        return N_("E527: Missing comma");
       } else {
-        if (args->os_errbuf != NULL) {
-          vim_snprintf(args->os_errbuf, args->os_errbuflen,
-                       _("E535: Illegal character after <%c>"),
-                       *--s);
-          return args->os_errbuf;
-        }
         return "";
       }
     }
   }
+  if (*p_shada && get_shada_parameter('\'') < 0) {
+    return N_("E528: Must specify a ' value");
+  }
   return NULL;
 }
 
-/// The 'completeopt' option is changed.
-const char *did_set_completeopt(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'shortmess' option is changed.
+const char *did_set_shortmess(optset_T *args)
 {
-  if (check_opt_strings(p_cot, p_cot_values, true) != OK) {
-    return e_invarg;
-  }
-  completeopt_was_set();
-  return NULL;
+  char **varp = (char **)args->os_varp;
+
+  return did_set_option_listflag(*varp, SHM_ALL, args->os_errbuf, args->os_errbuflen);
 }
 
-#ifdef BACKSLASH_IN_FILENAME
-/// The 'completeslash' option is changed.
-const char *did_set_completeslash(optset_T *args)
+/// The 'showbreak' option is changed.
+const char *did_set_showbreak(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
-  if (check_opt_strings(p_csl, p_csl_values, false) != OK
-      || check_opt_strings(buf->b_p_csl, p_csl_values, false) != OK) {
-    return e_invarg;
+  char **varp = (char **)args->os_varp;
+
+  for (char *s = *varp; *s;) {
+    if (ptr2cells(s) != 1) {
+      return e_showbreak_contains_unprintable_or_wide_character;
+    }
+    MB_PTR_ADV(s);
   }
   return NULL;
 }
-#endif
 
 /// The 'showcmdloc' option is changed.
 const char *did_set_showcmdloc(optset_T *args FUNC_ATTR_UNUSED)
@@ -1690,233 +1700,182 @@ const char *did_set_signcolumn(optset_T *args)
   return NULL;
 }
 
-/// The 'foldcolumn' option is changed.
-const char *did_set_foldcolumn(optset_T *args)
-{
-  char **varp = (char **)args->os_varp;
-  if (**varp == NUL || check_opt_strings(*varp, p_fdc_values, false) != OK) {
-    return e_invarg;
-  }
-  return NULL;
-}
-
-/// The 'backspace' option is changed.
-const char *did_set_backspace(optset_T *args FUNC_ATTR_UNUSED)
-{
-  if (ascii_isdigit(*p_bs)) {
-    if (*p_bs != '2') {
-      return e_invarg;
-    }
-  } else if (check_opt_strings(p_bs, p_bs_values, true) != OK) {
-    return e_invarg;
-  }
-  return NULL;
-}
-
-/// The 'switchbuf' option is changed.
-const char *did_set_switchbuf(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'spellcapcheck' option is changed.
+const char *did_set_spellcapcheck(optset_T *args)
 {
-  return did_set_opt_flags(p_swb, p_swb_values, &swb_flags, true);
+  win_T *win = (win_T *)args->os_win;
+  // When 'spellcapcheck' is set compile the regexp program.
+  return compile_cap_prog(win->w_s);
 }
 
-/// The 'tagcase' option is changed.
-const char *did_set_tagcase(optset_T *args)
+/// The 'spellfile' option is changed.
+const char *did_set_spellfile(optset_T *args)
 {
-  buf_T *buf = (buf_T *)args->os_buf;
-  int opt_flags = args->os_flags;
-
-  unsigned *flags;
-  char *p;
-
-  if (opt_flags & OPT_LOCAL) {
-    p = buf->b_p_tc;
-    flags = &buf->b_tc_flags;
-  } else {
-    p = p_tc;
-    flags = &tc_flags;
-  }
+  char **varp = (char **)args->os_varp;
 
-  if ((opt_flags & OPT_LOCAL) && *p == NUL) {
-    // make the local value empty: use the global value
-    *flags = 0;
-  } else if (*p == NUL
-             || opt_strings_flags(p, p_tc_values, flags, false) != OK) {
+  // When there is a window for this buffer in which 'spell'
+  // is set load the wordlists.
+  if ((!valid_spellfile(*varp))) {
     return e_invarg;
   }
-  return NULL;
+  return did_set_spell_option(true);
 }
 
-/// The 'debug' option is changed.
-const char *did_set_debug(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'spelllang' option is changed.
+const char *did_set_spelllang(optset_T *args)
 {
-  return did_set_opt_strings(p_debug, p_debug_values, false);
-}
+  char **varp = (char **)args->os_varp;
 
-/// The 'diffopt' option is changed.
-const char *did_set_diffopt(optset_T *args FUNC_ATTR_UNUSED)
-{
-  if (diffopt_changed() == FAIL) {
+  // When there is a window for this buffer in which 'spell'
+  // is set load the wordlists.
+  if (!valid_spelllang(*varp)) {
     return e_invarg;
   }
-  return NULL;
+  return did_set_spell_option(false);
 }
 
-/// The 'foldmethod' option is changed.
-const char *did_set_foldmethod(optset_T *args)
+/// The 'spelloptions' option is changed.
+const char *did_set_spelloptions(optset_T *args)
 {
   win_T *win = (win_T *)args->os_win;
-  char **varp = (char **)args->os_varp;
-  if (check_opt_strings(*varp, p_fdm_values, false) != OK
-      || *win->w_p_fdm == NUL) {
+  if (opt_strings_flags(win->w_s->b_p_spo, p_spo_values, &(win->w_s->b_p_spo_flags),
+                        true) != OK) {
     return e_invarg;
   }
-  foldUpdateAll(win);
-  if (foldmethodIsDiff(win)) {
-    newFoldLevel();
-  }
   return NULL;
 }
 
-/// The 'foldmarker' option is changed.
-const char *did_set_foldmarker(optset_T *args)
+/// The 'spellsuggest' option is changed.
+const char *did_set_spellsuggest(optset_T *args FUNC_ATTR_UNUSED)
 {
-  win_T *win = (win_T *)args->os_win;
-  char **varp = (char **)args->os_varp;
-  char *p = vim_strchr(*varp, ',');
-
-  if (p == NULL) {
-    return e_comma_required;
-  }
-
-  if (p == *varp || p[1] == NUL) {
+  if (spell_check_sps() != OK) {
     return e_invarg;
   }
-
-  if (foldmethodIsMarker(win)) {
-    foldUpdateAll(win);
-  }
-
   return NULL;
 }
 
-/// The 'commentstring' option is changed.
-const char *did_set_commentstring(optset_T *args)
+/// The 'splitkeep' option is changed.
+const char *did_set_splitkeep(optset_T *args FUNC_ATTR_UNUSED)
 {
-  char **varp = (char **)args->os_varp;
+  return did_set_opt_strings(p_spk, p_spk_values, false);
+}
 
-  if (**varp != NUL && strstr(*varp, "%s") == NULL) {
-    return N_("E537: 'commentstring' must be empty or contain %s");
-  }
-  return NULL;
+/// The 'statuscolumn' option is changed.
+const char *did_set_statuscolumn(optset_T *args)
+{
+  return did_set_statustabline_rulerformat(args, false, true);
 }
 
-/// The 'foldignore' option is changed.
-const char *did_set_foldignore(optset_T *args)
+/// The 'statusline' option is changed.
+const char *did_set_statusline(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
-  if (foldmethodIsIndent(win)) {
-    foldUpdateAll(win);
-  }
-  return NULL;
+  return did_set_statustabline_rulerformat(args, false, false);
 }
 
-/// The 'virtualedit' option is changed.
-const char *did_set_virtualedit(optset_T *args)
+/// The 'statusline', 'winbar', 'tabline', 'rulerformat' or 'statuscolumn' option is changed.
+///
+/// @param rulerformat  true if the 'rulerformat' option is changed
+/// @param statuscolumn  true if the 'statuscolumn' option is changed
+static const char *did_set_statustabline_rulerformat(optset_T *args, bool rulerformat,
+                                                     bool statuscolumn)
 {
   win_T *win = (win_T *)args->os_win;
-
-  char *ve = p_ve;
-  unsigned *flags = &ve_flags;
-
-  if (args->os_flags & OPT_LOCAL) {
-    ve = win->w_p_ve;
-    flags = &win->w_ve_flags;
+  char **varp = (char **)args->os_varp;
+  if (rulerformat) {       // reset ru_wid first
+    ru_wid = 0;
+  } else if (statuscolumn) {
+    // reset 'statuscolumn' width
+    win->w_nrwidth_line_count = 0;
   }
-
-  if ((args->os_flags & OPT_LOCAL) && *ve == NUL) {
-    // make the local value empty: use the global value
-    *flags = 0;
-  } else {
-    if (opt_strings_flags(ve, p_ve_values, flags, true) != OK) {
-      return e_invarg;
-    } else if (strcmp(ve, args->os_oldval.string) != 0) {
-      // Recompute cursor position in case the new 've' setting
-      // changes something.
-      validate_virtcol_win(win);
-      // XXX: this only works when win == curwin
-      coladvance(win->w_virtcol);
+  const char *errmsg = NULL;
+  char *s = *varp;
+  if (rulerformat && *s == '%') {
+    // set ru_wid if 'ruf' starts with "%99("
+    if (*++s == '-') {        // ignore a '-'
+      s++;
+    }
+    int wid = getdigits_int(&s, true, 0);
+    if (wid && *s == '(' && (errmsg = check_stl_option(p_ruf)) == NULL) {
+      ru_wid = wid;
+    } else {
+      errmsg = check_stl_option(p_ruf);
     }
+  } else if (rulerformat || s[0] != '%' || s[1] != '!') {
+    // check 'statusline', 'winbar', 'tabline' or 'statuscolumn'
+    // only if it doesn't start with "%!"
+    errmsg = check_stl_option(s);
   }
-  return NULL;
+  if (rulerformat && errmsg == NULL) {
+    comp_col();
+  }
+  return errmsg;
 }
 
-/// The 'jumpoptions' option is changed.
-const char *did_set_jumpoptions(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'switchbuf' option is changed.
+const char *did_set_switchbuf(optset_T *args FUNC_ATTR_UNUSED)
 {
-  return did_set_opt_flags(p_jop, p_jop_values, &jop_flags, true);
+  return did_set_opt_flags(p_swb, p_swb_values, &swb_flags, true);
 }
 
-/// The 'redrawdebug' option is changed.
-const char *did_set_redrawdebug(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'tabline' option is changed.
+const char *did_set_tabline(optset_T *args)
 {
-  return did_set_opt_flags(p_rdb, p_rdb_values, &rdb_flags, true);
+  return did_set_statustabline_rulerformat(args, false, false);
 }
 
-/// The 'wildoptions' option is changed.
-const char *did_set_wildoptions(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'tagcase' option is changed.
+const char *did_set_tagcase(optset_T *args)
 {
-  return did_set_opt_flags(p_wop, p_wop_values, &wop_flags, true);
-}
+  buf_T *buf = (buf_T *)args->os_buf;
+  int opt_flags = args->os_flags;
 
-/// The 'lispoptions' option is changed.
-const char *did_set_lispoptions(optset_T *args)
-{
-  char **varp = (char **)args->os_varp;
+  unsigned *flags;
+  char *p;
 
-  if (**varp != NUL && strcmp(*varp, "expr:0") != 0 && strcmp(*varp, "expr:1") != 0) {
+  if (opt_flags & OPT_LOCAL) {
+    p = buf->b_p_tc;
+    flags = &buf->b_tc_flags;
+  } else {
+    p = p_tc;
+    flags = &tc_flags;
+  }
+
+  if ((opt_flags & OPT_LOCAL) && *p == NUL) {
+    // make the local value empty: use the global value
+    *flags = 0;
+  } else if (*p == NUL
+             || opt_strings_flags(p, p_tc_values, flags, false) != OK) {
     return e_invarg;
   }
   return NULL;
 }
 
-/// The 'rightleftcmd' option is changed.
-const char *did_set_rightleftcmd(optset_T *args)
+/// The 'termpastefilter' option is changed.
+const char *did_set_termpastefilter(optset_T *args FUNC_ATTR_UNUSED)
 {
-  char **varp = (char **)args->os_varp;
-
-  // Currently only "search" is a supported value.
-  if (**varp != NUL && strcmp(*varp, "search") != 0) {
-    return e_invarg;
-  }
-
-  return NULL;
+  return did_set_opt_flags(p_tpf, p_tpf_values, &tpf_flags, true);
 }
 
-/// The 'filetype' or the 'syntax' option is changed.
-const char *did_set_filetype_or_syntax(optset_T *args)
+/// The 'titlestring' or the 'iconstring' option is changed.
+static const char *did_set_titleiconstring(optset_T *args, int flagval)
 {
   char **varp = (char **)args->os_varp;
 
-  if (!valid_filetype(*varp)) {
-    return e_invarg;
+  // NULL => statusline syntax
+  if (vim_strchr(*varp, '%') && check_stl_option(*varp) == NULL) {
+    stl_syntax |= flagval;
+  } else {
+    stl_syntax &= ~flagval;
   }
-
-  args->os_value_changed = strcmp(args->os_oldval.string, *varp) != 0;
-
-  // Since we check the value, there is no need to set P_INSECURE,
-  // even when the value comes from a modeline.
-  args->os_value_checked = true;
+  did_set_title();
 
   return NULL;
 }
 
-const char *did_set_winhl(optset_T *args)
+/// The 'titlestring' option is changed.
+const char *did_set_titlestring(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
-  if (!parse_winhl_opt(win)) {
-    return e_invarg;
-  }
-  return NULL;
+  return did_set_titleiconstring(args, STL_IN_TITLE);
 }
 
 /// The 'varsofttabstop' option is changed.
@@ -1983,62 +1942,97 @@ const char *did_set_vartabstop(optset_T *args)
   return NULL;
 }
 
-/// The 'nrformats' option is changed.
-const char *did_set_nrformats(optset_T *args)
+/// The 'verbosefile' option is changed.
+const char *did_set_verbosefile(optset_T *args)
 {
-  char **varp = (char **)args->os_varp;
+  verbose_stop();
+  if (*p_vfile != NUL && verbose_open() == FAIL) {
+    return (char *)e_invarg;
+  }
+  return NULL;
+}
 
-  return did_set_opt_strings(*varp, p_nf_values, true);
+/// The 'viewoptions' option is changed.
+const char *did_set_viewoptions(optset_T *args FUNC_ATTR_UNUSED)
+{
+  return did_set_opt_flags(p_vop, p_ssop_values, &vop_flags, true);
 }
 
-/// One of the '*expr' options is changed:, 'diffexpr', 'foldexpr', 'foldtext',
-/// 'formatexpr', 'includeexpr', 'indentexpr', 'patchexpr' and 'charconvert'.
-const char *did_set_optexpr(optset_T *args)
+/// The 'virtualedit' option is changed.
+const char *did_set_virtualedit(optset_T *args)
 {
-  char **varp = (char **)args->os_varp;
+  win_T *win = (win_T *)args->os_win;
 
-  // If the option value starts with <SID> or s:, then replace that with
-  // the script identifier.
-  char *name = get_scriptlocal_funcname(*varp);
-  if (name != NULL) {
-    free_string_option(*varp);
-    *varp = name;
+  char *ve = p_ve;
+  unsigned *flags = &ve_flags;
+
+  if (args->os_flags & OPT_LOCAL) {
+    ve = win->w_p_ve;
+    flags = &win->w_ve_flags;
+  }
+
+  if ((args->os_flags & OPT_LOCAL) && *ve == NUL) {
+    // make the local value empty: use the global value
+    *flags = 0;
+  } else {
+    if (opt_strings_flags(ve, p_ve_values, flags, true) != OK) {
+      return e_invarg;
+    } else if (strcmp(ve, args->os_oldval.string) != 0) {
+      // Recompute cursor position in case the new 've' setting
+      // changes something.
+      validate_virtcol_win(win);
+      // XXX: this only works when win == curwin
+      coladvance(win->w_virtcol);
+    }
   }
   return NULL;
 }
 
-/// The 'foldexpr' option is changed.
-const char *did_set_foldexpr(optset_T *args)
+/// The 'whichwrap' option is changed.
+const char *did_set_whichwrap(optset_T *args)
 {
-  win_T *win = (win_T *)args->os_win;
-  (void)did_set_optexpr(args);
-  if (foldmethodIsExpr(win)) {
-    foldUpdateAll(win);
+  char **varp = (char **)args->os_varp;
+
+  return did_set_option_listflag(*varp, WW_ALL, args->os_errbuf, args->os_errbuflen);
+}
+
+/// The 'wildmode' option is changed.
+const char *did_set_wildmode(optset_T *args FUNC_ATTR_UNUSED)
+{
+  if (check_opt_wim() == FAIL) {
+    return e_invarg;
   }
   return NULL;
 }
 
-/// The 'foldclose' option is changed.
-const char *did_set_foldclose(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'wildoptions' option is changed.
+const char *did_set_wildoptions(optset_T *args FUNC_ATTR_UNUSED)
 {
-  return did_set_opt_strings(p_fcl, p_fcl_values, true);
+  return did_set_opt_flags(p_wop, p_wop_values, &wop_flags, true);
 }
 
-/// An option which is a list of flags is set.  Valid values are in 'flags'.
-static const char *did_set_option_listflag(char *val, char *flags, char *errbuf, size_t errbuflen)
+/// The 'winaltkeys' option is changed.
+const char *did_set_winaltkeys(optset_T *args FUNC_ATTR_UNUSED)
 {
-  for (char *s = val; *s; s++) {
-    if (vim_strchr(flags, (uint8_t)(*s)) == NULL) {
-      return illegal_char(errbuf, errbuflen, (uint8_t)(*s));
-    }
+  if (*p_wak == NUL || check_opt_strings(p_wak, p_wak_values, false) != OK) {
+    return e_invarg;
   }
-
   return NULL;
 }
 
-const char *did_set_guicursor(optset_T *args FUNC_ATTR_UNUSED)
+/// The 'winbar' option is changed.
+const char *did_set_winbar(optset_T *args)
 {
-  return parse_shape_opt(SHAPE_CURSOR);
+  return did_set_statustabline_rulerformat(args, false, false);
+}
+
+const char *did_set_winhl(optset_T *args)
+{
+  win_T *win = (win_T *)args->os_win;
+  if (!parse_winhl_opt(win)) {
+    return e_invarg;
+  }
+  return NULL;
 }
 
 // When 'syntax' is set, load the syntax of that name
@@ -2564,3 +2558,15 @@ const char *check_chars_options(void)
   }
   return NULL;
 }
+
+/// Handle the new value of 'fillchars'.
+const char *set_fillchars_option(win_T *wp, char *val, bool apply)
+{
+  return set_chars_option(wp, val, false, apply);
+}
+
+/// Handle the new value of 'listchars'.
+const char *set_listchars_option(win_T *wp, char *val, bool apply)
+{
+  return set_chars_option(wp, val, true, apply);
+}