refactor!: delete insertmode (#18547)

Neovim already removed `evim` (or any similar flags). The 'insertmode'
option is a weird remnant, so get rid of it.

The 'insertmode' option is replaced with a script that closely emulates
the option. This script is documented at :help 'insertmode'

src/nvim/edit.c

@@ -459,9 +459,8 @@ static void insert_enter(InsertState *s)
 
   where_paste_started.lnum = 0;
   can_cindent = true;
-  // The cursor line is not in a closed fold, unless 'insertmode' is set or
-  // restarting.
-  if (!p_im && did_restart_edit == 0) {
+  // The cursor line is not in a closed fold, unless restarting.
+  if (did_restart_edit == 0) {
     foldOpenCursor();
   }
 
@@ -473,7 +472,7 @@ static void insert_enter(InsertState *s)
     s->i = showmode();
   }
 
-  if (!p_im && did_restart_edit == 0) {
+  if (did_restart_edit == 0) {
     change_warning(curbuf, s->i == 0 ? 0 : s->i + 1);
   }
 
@@ -554,7 +553,7 @@ static int insert_check(VimState *state)
   }
 
   if (stop_insert_mode && !compl_started) {
-    // ":stopinsert" used or 'insertmode' reset
+    // ":stopinsert" used
     s->count = 0;
     return 0;  // exit insert mode
   }
@@ -756,7 +755,6 @@ static int insert_execute(VimState *state, int key)
   }
 
   // CTRL-\ CTRL-N goes to Normal mode,
-  // CTRL-\ CTRL-G goes to mode selected with 'insertmode',
   // CTRL-\ CTRL-O is like CTRL-O but without moving the cursor
   if (s->c == Ctrl_BSL) {
     // may need to redraw when no more chars available now
@@ -770,8 +768,6 @@ static int insert_execute(VimState *state, int key)
       // it's something else
       vungetc(s->c);
       s->c = Ctrl_BSL;
-    } else if (s->c == Ctrl_G && p_im) {
-      return 1;  // continue
     } else {
       if (s->c == Ctrl_O) {
         ins_ctrl_o();
@@ -843,16 +839,6 @@ static int insert_execute(VimState *state, int key)
 }
 
 
-/// Return true when need to go to Insert mode because of 'insertmode'.
-///
-/// Don't do this when still processing a command or a mapping.
-/// Don't do this when inside a ":normal" command.
-bool goto_im(void)
-  FUNC_ATTR_PURE
-{
-  return p_im && stuff_empty() && typebuf_typed();
-}
-
 static int insert_handle_key(InsertState *s)
 {
   // The big switch to handle a character in insert mode.
@@ -884,26 +870,10 @@ static int insert_handle_key(InsertState *s)
       }
     }
 
-    // when 'insertmode' set, and not halfway through a mapping, don't leave
-    // Insert mode
-    if (goto_im()) {
-      if (got_int) {
-        (void)vgetc();                        // flush all buffers
-        got_int = false;
-      } else {
-        vim_beep(BO_IM);
-      }
-      break;
-    }
     return 0;  // exit insert mode
 
-  case Ctrl_Z:        // suspend when 'insertmode' set
-    if (!p_im) {
-      goto normalchar;                // insert CTRL-Z as normal char
-    }
-    do_cmdline_cmd("stop");
-    ui_cursor_shape();  // may need to update cursor shape
-    break;
+  case Ctrl_Z:
+    goto normalchar;                // insert CTRL-Z as normal char
 
   case Ctrl_O:        // execute one command
     if (ctrl_x_mode == CTRL_X_OMNI) {
@@ -939,9 +909,6 @@ static int insert_handle_key(InsertState *s)
   case K_F1:
   case K_XF1:
     stuffcharReadbuff(K_HELP);
-    if (p_im) {
-      need_start_insertmode = true;
-    }
     return 0;  // exit insert mode
 
 
@@ -956,7 +923,7 @@ static int insert_handle_key(InsertState *s)
     // For ^@ the trailing ESC will end the insert, unless there is an
     // error.
     if (stuff_inserted(NUL, 1L, (s->c == Ctrl_A)) == FAIL
-        && s->c != Ctrl_A && !p_im) {
+        && s->c != Ctrl_A) {
       return 0;  // exit insert mode
     }
     s->inserted_space = false;
@@ -1236,7 +1203,7 @@ check_pum:
       }
       break;
     }
-    if (!ins_eol(s->c) && !p_im) {
+    if (!ins_eol(s->c)) {
       return 0;  // out of memory
     }
     auto_format(false, false);
@@ -1288,13 +1255,6 @@ check_pum:
 
   case Ctrl_L:        // Whole line completion after ^X
     if (ctrl_x_mode != CTRL_X_WHOLE_LINE) {
-      // CTRL-L with 'insertmode' set: Leave Insert mode
-      if (p_im) {
-        if (echeck_abbr(Ctrl_L + ABBR_OFF)) {
-          break;
-        }
-        return 0;  // exit insert mode
-      }
       goto normalchar;
     }
     FALLTHROUGH;
@@ -7964,10 +7924,8 @@ static bool ins_esc(long *count, int cmdchar, bool nomove)
   }
   if (!arrow_used) {
     // Don't append the ESC for "r<CR>" and "grx".
-    // When 'insertmode' is set only CTRL-L stops Insert mode.  Needed for
-    // when "count" is non-zero.
     if (cmdchar != 'r' && cmdchar != 'v') {
-      AppendToRedobuff(p_im ? "\014" : ESC_STR);
+      AppendToRedobuff(ESC_STR);
     }
 
     /*

src/nvim/ex_cmds.c

@@ -2880,10 +2880,6 @@ int do_ecmd(int fnum, char *ffname, char *sfname, exarg_T *eap, linenr_T newlnum
     redraw_curbuf_later(NOT_VALID);     // redraw this buffer later
   }
 
-  if (p_im && (State & MODE_INSERT) == 0) {
-    need_start_insertmode = true;
-  }
-
   // Change directories when the 'acd' option is set.
   do_autochdir();
 
@@ -4909,9 +4905,8 @@ void ex_help(exarg_T *eap)
     }
   }
 
-  if (!p_im) {
-    restart_edit = 0;               // don't want insert mode in help file
-  }
+  restart_edit = 0;               // don't want insert mode in help file
+
   // Restore KeyTyped, setting 'filetype=help' may reset it.
   // It is needed for do_tag top open folds under the cursor.
   KeyTyped = old_KeyTyped;

src/nvim/ex_docmd.c

@@ -8979,7 +8979,6 @@ bool save_current_state(save_state_T *sst)
   sst->save_restart_edit = restart_edit;
   sst->save_msg_didout = msg_didout;
   sst->save_State = State;
-  sst->save_insertmode = p_im;
   sst->save_finish_op = finish_op;
   sst->save_opcount = opcount;
   sst->save_reg_executing = reg_executing;
@@ -8987,7 +8986,6 @@ bool save_current_state(save_state_T *sst)
 
   msg_scroll = false;   // no msg scrolling in Normal mode
   restart_edit = 0;     // don't go to Insert mode
-  p_im = false;         // don't use 'insertmode
 
   // Save the current typeahead.  This is required to allow using ":normal"
   // from an event handler and makes sure we don't hang when the argument
@@ -9010,7 +9008,6 @@ void restore_current_state(save_state_T *sst)
     // override the value of restart_edit anyway.
     restart_edit = sst->save_restart_edit;
   }
-  p_im = sst->save_insertmode;
   finish_op = sst->save_finish_op;
   opcount = sst->save_opcount;
   reg_executing = sst->save_reg_executing;

src/nvim/ex_docmd.h

@@ -25,7 +25,6 @@ typedef struct {
   int save_restart_edit;
   bool save_msg_didout;
   int save_State;
-  int save_insertmode;
   bool save_finish_op;
   long save_opcount;
   int save_reg_executing;

src/nvim/ex_getln.c

@@ -1336,8 +1336,7 @@ static int command_line_execute(VimState *state, int key)
     }
   }
 
-  // CTRL-\ CTRL-N goes to Normal mode, CTRL-\ CTRL-G goes to Insert
-  // mode when 'insertmode' is set, CTRL-\ e prompts for an expression.
+  // CTRL-\ CTRL-N goes to Normal mode, CTRL-\ e prompts for an expression.
   if (s->c == Ctrl_BSL) {
     no_mapping++;
     allow_keys++;
@@ -1399,9 +1398,6 @@ static int command_line_execute(VimState *state, int key)
       redrawcmd();
       return command_line_not_changed(s);
     } else {
-      if (s->c == Ctrl_G && p_im && restart_edit == 0) {
-        restart_edit = 'a';
-      }
       s->gotesc = true;        // will free ccline.cmdbuff after putting it
                                // in history
       return 0;                // back to Normal mode

src/nvim/getchar.c

@@ -1352,14 +1352,12 @@ void openscript(char_u *name, bool directly)
     int oldcurscript;
     int save_State = State;
     int save_restart_edit = restart_edit;
-    int save_insertmode = p_im;
     int save_finish_op = finish_op;
     int save_msg_scroll = msg_scroll;
 
     State = MODE_NORMAL;
     msg_scroll = false;         // no msg scrolling in Normal mode
     restart_edit = 0;           // don't go to Insert mode
-    p_im = false;               // don't use 'insertmode'
     clear_oparg(&oa);
     finish_op = false;
 
@@ -1373,7 +1371,6 @@ void openscript(char_u *name, bool directly)
     State = save_State;
     msg_scroll = save_msg_scroll;
     restart_edit = save_restart_edit;
-    p_im = save_insertmode;
     finish_op = save_finish_op;
   }
 }
@@ -2513,16 +2510,12 @@ static int vgetorpeek(bool advance)
             timedout = true;
             continue;
           }
-          // When 'insertmode' is set, ESC just beeps in Insert
-          // mode.  Use CTRL-L to make edit() return.
           // In Ex-mode \n is compatible with original Vim behaviour.
           // For the command line only CTRL-C always breaks it.
           // For the cmdline window: Alternate between ESC and
           // CTRL-C: ESC for most situations and CTRL-C to close the
           // cmdline window.
-          if (p_im && (State & MODE_INSERT)) {
-            c = Ctrl_L;
-          } else if ((State & MODE_CMDLINE) || (cmdwin_type > 0 && tc == ESC)) {
+          if ((State & MODE_CMDLINE) || (cmdwin_type > 0 && tc == ESC)) {
             c = Ctrl_C;
           } else {
             c = ESC;

src/nvim/main.c

@@ -530,11 +530,6 @@ int main(int argc, char **argv)
   // 'autochdir' has been postponed.
   do_autochdir();
 
-  // start in insert mode
-  if (p_im) {
-    need_start_insertmode = true;
-  }
-
   set_vim_var_nr(VV_VIM_DID_ENTER, 1L);
   apply_autocmds(EVENT_VIMENTER, NULL, NULL, false, curbuf);
   TIME_MSG("VimEnter autocommands");

src/nvim/normal.c

@@ -1126,9 +1126,6 @@ static int normal_execute(VimState *state, int key)
 
   if (s->ca.nchar == ESC) {
     clearop(&s->oa);
-    if (restart_edit == 0 && goto_im()) {
-      restart_edit = 'a';
-    }
     s->command_finished = true;
     goto finish;
   }
@@ -1178,14 +1175,6 @@ static void normal_check_stuff_buffer(NormalState *s)
       // if wait_return still needed call it now
       wait_return(false);
     }
-
-    if (need_start_insertmode && goto_im() && !VIsual_active) {
-      need_start_insertmode = false;
-      stuffReadbuff("i");  // start insert mode next
-      // skip the fileinfo message now, because it would be shown
-      // after insert mode finishes!
-      need_fileinfo = false;
-    }
   }
 }
 
@@ -3904,7 +3893,6 @@ static void nv_regreplay(cmdarg_T *cap)
 /// Handle a ":" command and <Cmd> or Lua keymaps.
 static void nv_colon(cmdarg_T *cap)
 {
-  int old_p_im;
   bool cmd_result;
   bool is_cmdkey = cap->cmdchar == K_COMMAND;
   bool is_lua = cap->cmdchar == K_LUA;
@@ -3930,8 +3918,6 @@ static void nv_colon(cmdarg_T *cap)
       compute_cmdrow();
     }
 
-    old_p_im = p_im;
-
     if (is_lua) {
       cmd_result = map_execute_lua();
     } else {
@@ -3940,15 +3926,6 @@ static void nv_colon(cmdarg_T *cap)
                               cap->oap->op_type != OP_NOP ? DOCMD_KEEPLINE : 0);
     }
 
-    // If 'insertmode' changed, enter or exit Insert mode
-    if (p_im != old_p_im) {
-      if (p_im) {
-        restart_edit = 'i';
-      } else {
-        restart_edit = 0;
-      }
-    }
-
     if (cmd_result == false) {
       // The Ex command failed, do not execute the operator.
       clearop(cap->oap);
@@ -6735,10 +6712,6 @@ static void nv_normal(cmdarg_T *cap)
       end_visual_mode();                // stop Visual
       redraw_curbuf_later(INVERTED);
     }
-    // CTRL-\ CTRL-G restarts Insert mode when 'insertmode' is set.
-    if (cap->nchar == Ctrl_G && p_im) {
-      restart_edit = 'a';
-    }
   } else {
     clearopbeep(cap->oap);
   }
@@ -6753,8 +6726,7 @@ static void nv_esc(cmdarg_T *cap)
   no_reason = (cap->oap->op_type == OP_NOP
                && cap->opcount == 0
                && cap->count0 == 0
-               && cap->oap->regname == 0
-               && !p_im);
+               && cap->oap->regname == 0);
 
   if (cap->arg) {               // true for CTRL-C
     if (restart_edit == 0
@@ -6771,9 +6743,8 @@ static void nv_esc(cmdarg_T *cap)
 
     // Don't reset "restart_edit" when 'insertmode' is set, it won't be
     // set again below when halfway through a mapping.
-    if (!p_im) {
-      restart_edit = 0;
-    }
+    restart_edit = 0;
+
     if (cmdwin_type != 0) {
       cmdwin_result = K_IGNORE;
       got_int = false;          // don't stop executing autocommands et al.
@@ -6796,13 +6767,6 @@ static void nv_esc(cmdarg_T *cap)
     vim_beep(BO_ESC);
   }
   clearop(cap->oap);
-
-  // A CTRL-C is often used at the start of a menu.  When 'insertmode' is
-  // set return to Insert mode afterwards.
-  if (restart_edit == 0 && goto_im()
-      && ex_normal_busy == 0) {
-    restart_edit = 'a';
-  }
 }
 
 // Move the cursor for the "A" command.
@@ -6837,8 +6801,7 @@ static void nv_edit(cmdarg_T *cap)
   } else if ((cap->cmdchar == 'a' || cap->cmdchar == 'i')
              && (cap->oap->op_type != OP_NOP || VIsual_active)) {
     nv_object(cap);
-  } else if (!curbuf->b_p_ma && !p_im && !curbuf->terminal) {
-    // Only give this error when 'insertmode' is off.
+  } else if (!curbuf->b_p_ma && !curbuf->terminal) {
     emsg(_(e_modifiable));
     clearop(cap->oap);
   } else if (!checkclearopq(cap->oap)) {

src/nvim/ops.c

@@ -6719,7 +6719,7 @@ void do_pending_operator(cmdarg_T *cap, int old_col, bool gui_yank)
         // remember it to make 'insertmode' work with mappings for
         // Visual mode.  But do this only once and not when typed and
         // 'insertmode' isn't set.
-        if (p_im || !KeyTyped) {
+        if (!KeyTyped) {
           restart_edit_save = restart_edit;
         } else {
           restart_edit_save = 0;

src/nvim/option.c

@@ -4052,21 +4052,6 @@ static char *set_bool_option(const int opt_idx, char_u *const varp, const int va
   } else if ((int *)varp == &p_paste) {
     // when 'paste' is set or reset also change other options
     paste_option_changed();
-  } else if ((int *)varp == &p_im) {
-    // when 'insertmode' is set from an autocommand need to do work here
-    if (p_im) {
-      if ((State & MODE_INSERT) == 0) {
-        need_start_insertmode = true;
-      }
-      stop_insert_mode = false;
-    } else if (old_value) {  // only reset if it was set previously
-      need_start_insertmode = false;
-      stop_insert_mode = true;
-      if (restart_edit != 0 && mode_displayed) {
-        clear_cmdline = true;  // remove "(insert)"
-      }
-      restart_edit = 0;
-    }
   } else if ((int *)varp == &p_ic && p_hls) {
     // when 'ignorecase' is set or reset and 'hlsearch' is set, redraw
     redraw_all_later(SOME_VALID);

src/nvim/option_defs.h

@@ -334,9 +334,9 @@ EXTERN unsigned bo_flags;
 #ifdef IN_OPTION_C
 static char *(p_bo_values[]) = { "all", "backspace", "cursor", "complete",
                                  "copy", "ctrlg", "error", "esc", "ex",
-                                 "hangul", "insertmode", "lang", "mess",
-                                 "showmatch", "operator", "register", "shell",
-                                 "spell", "wildmode", NULL };
+                                 "hangul", "lang", "mess", "showmatch",
+                                 "operator", "register", "shell", "spell",
+                                 "wildmode", NULL };
 #endif
 
 // values for the 'belloff' option
@@ -485,7 +485,6 @@ EXTERN char_u *p_iconstring;  // 'iconstring'
 EXTERN int p_ic;                // 'ignorecase'
 EXTERN int p_is;                // 'incsearch'
 EXTERN char_u *p_icm;         // 'inccommand'
-EXTERN int p_im;                // 'insertmode'
 EXTERN char_u *p_isf;         // 'isfname'
 EXTERN char_u *p_isi;         // 'isident'
 EXTERN char_u *p_isp;         // 'isprint'

src/nvim/options.lua

@@ -1250,9 +1250,9 @@ return {
     },
     {
       full_name='insertmode', abbreviation='im',
-      short_desc=N_("start the edit of a file in Insert mode"),
+      short_desc=N_("No description"),
       type='bool', scope={'global'},
-      varname='p_im',
+      varname='p_force_off',
       defaults={if_true=false}
     },
     {

src/nvim/quickfix.c

@@ -2540,9 +2540,7 @@ static int jump_to_help_window(qf_info_T *qi, bool newwin, int *opened_window)
     }
   }
 
-  if (!p_im) {
-    restart_edit = 0;  // don't want insert mode in help file
-  }
+  restart_edit = 0;  // don't want insert mode in help file
 
   return OK;
 }

src/nvim/testdir/test_edit.vim

@@ -16,8 +16,9 @@ func Test_edit_00b()
   call setline(1, ['abc '])
   inoreabbr <buffer> h here some more
   call cursor(1, 4)
-  " <c-l> expands the abbreviation and ends insertmode
-  call feedkeys(":set im\<cr> h\<c-l>:set noim\<cr>", 'tix')
+  " <esc> expands the abbreviation and ends insert mode
+  " call feedkeys(":set im\<cr> h\<c-l>:set noim\<cr>", 'tix')
+  call feedkeys("i h\<esc>", 'tix')
   call assert_equal(['abc here some more '], getline(1,'$'))
   iunabbr <buffer> h
   bw!
@@ -234,15 +235,18 @@ func Test_edit_09()
   call setline(1, ['abc', 'def', 'ghi'])
   call cursor(1, 1)
   " 1) CTRL-\ CTLR-N
-  call feedkeys(":set im\<cr>\<c-\>\<c-n>ccABC\<c-l>", 'txin')
+  " call feedkeys(":set im\<cr>\<c-\>\<c-n>ccABC\<c-l>", 'txin')
+  call feedkeys("i\<c-\>\<c-n>ccABC\<esc>", 'txin')
   call assert_equal(['ABC', 'def', 'ghi'], getline(1,'$'))
   call setline(1, ['ABC', 'def', 'ghi'])
   " 2) CTRL-\ CTLR-G
-  call feedkeys("j0\<c-\>\<c-g>ZZZ\<cr>\<c-l>", 'txin')
-  call assert_equal(['ABC', 'ZZZ', 'def', 'ghi'], getline(1,'$'))
-  call feedkeys("I\<c-\>\<c-g>YYY\<c-l>", 'txin')
-  call assert_equal(['ABC', 'ZZZ', 'YYYdef', 'ghi'], getline(1,'$'))
-  set noinsertmode
+  " CTRL-\ CTRL-G goes to Insert mode when 'insertmode' is set, but
+  " 'insertmode' is now removed so skip this test
+  " call feedkeys("j0\<c-\>\<c-g>ZZZ\<cr>\<esc>", 'txin')
+  " call assert_equal(['ABC', 'ZZZ', 'def', 'ghi'], getline(1,'$'))
+  " call feedkeys("I\<c-\>\<c-g>YYY\<c-l>", 'txin')
+  " call assert_equal(['ABC', 'ZZZ', 'YYYdef', 'ghi'], getline(1,'$'))
+  " set noinsertmode
   " 3) CTRL-\ CTRL-O
   call setline(1, ['ABC', 'ZZZ', 'def', 'ghi'])
   call cursor(1, 1)
@@ -1043,7 +1047,8 @@ endfunc
 func Test_edit_F1()
   " Pressing <f1>
   new
-  call feedkeys(":set im\<cr>\<f1>\<c-l>", 'tnix')
+  " call feedkeys(":set im\<cr>\<f1>\<c-l>", 'tnix')
+  call feedkeys("i\<f1>\<esc>", 'tnix')
   set noinsertmode
   call assert_equal('help', &buftype)
   bw

src/nvim/testdir/test_normal.vim

@@ -133,7 +133,8 @@ func Test_normal02_selectmode2()
   " some basic select mode tests
   call Setup_NewWindow()
   50
-  call feedkeys(":set im\n\<c-o>gHc\<c-o>:set noim\n", 'tx')
+  " call feedkeys(":set im\n\<c-o>gHc\<c-o>:set noim\n", 'tx')
+  call feedkeys("i\<c-o>gHc\<esc>", 'tx')
   call assert_equal('c51', getline('.'))
   " clean up
   bw!
@@ -2113,11 +2114,11 @@ fun! Test_normal40_ctrl_bsl()
   call assert_equal('n', mode())
   call assert_equal(1, col('.'))
   "imap <buffer> , <c-\><c-n>
-  set im
+  " set im
   exe ":norm! \<c-\>\<c-n>dw"
-  set noim
+  " set noim
   call assert_equal('are   some words', getline(1))
-  call assert_false(&insertmode)
+  " call assert_false(&insertmode)
 
   " clean up
   bw!