vim-patch:9.1.1779: completion: 'autocomplete' cannot be enabled per buffer (#35853)

Problem:  completion: 'autocomplete' cannot be enabled per buffer
          (Tomasz N)
Solution: Make 'autocomplete' global or local to buffer (Girish Palya)

fixes: vim/vim#18320
closes: vim/vim#18333

0208b3e80a

Co-authored-by: Girish Palya <girishji@gmail.com>

runtime/doc/options.txt

@@ -743,7 +743,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 			*'autocomplete'* *'ac'* *'noautocomplete'* *'noac'*
 'autocomplete' 'ac'	boolean	(default off)
-			global
+			global or local to buffer |global-local|
 	When on, Vim shows a completion menu as you type, similar to using
 	|i_CTRL-N|, but triggered automatically.  See |ins-autocompletion|.
 

runtime/lua/vim/_meta/options.lua

@@ -117,6 +117,8 @@ vim.go.acd = vim.go.autochdir
 --- @type boolean
 vim.o.autocomplete = false
 vim.o.ac = vim.o.autocomplete
+vim.bo.autocomplete = vim.o.autocomplete
+vim.bo.ac = vim.bo.autocomplete
 vim.go.autocomplete = vim.o.autocomplete
 vim.go.ac = vim.go.autocomplete
 

runtime/optwin.vim

@@ -1,7 +1,7 @@
 " These commands create the option window.
 "
 " Maintainer:	The Vim Project <https://github.com/vim/vim>
-" Last Change:	2025 Aug 23
+" Last Change:	2025 Sep 20
 " Former Maintainer:	Bram Moolenaar <Bram@vim.org>
 
 " If there already is an option window, jump to that one.
@@ -736,6 +736,7 @@ if has("insert_expand")
   call append("$", "\t" .. s:local_to_buffer)
   call <SID>OptionL("cpt")
   call <SID>AddOption("autocomplete", gettext("automatic completion in insert mode"))
+  call append("$", "\t" .. s:global_or_local)
   call <SID>BinOptionG("ac", &ac)
   call <SID>AddOption("autocompletetimeout", gettext("initial decay timeout for 'autocomplete' algorithm"))
   call append("$", " \tset act=" . &act)

src/nvim/buffer.c

@@ -2122,6 +2122,7 @@ void free_buf_options(buf_T *buf, bool free_p_ff)
   clear_string_option(&buf->b_p_dia);
   clear_string_option(&buf->b_p_tsr);
   clear_string_option(&buf->b_p_qe);
+  buf->b_p_ac = -1;
   buf->b_p_ar = -1;
   buf->b_p_ul = NO_LOCAL_UNDOLEVEL;
   clear_string_option(&buf->b_p_lw);

src/nvim/buffer_defs.h

@@ -514,6 +514,7 @@ struct file_buffer {
 
   sctx_T b_p_script_ctx[kBufOptCount];  // SCTXs for buffer-local options
 
+  int b_p_ac;                   ///< 'autocomplete'
   int b_p_ai;                   ///< 'autoindent'
   int b_p_ai_nopaste;           ///< b_p_ai saved for paste mode
   char *b_p_bkc;                ///< 'backupco

src/nvim/edit.c

@@ -605,7 +605,7 @@ static int insert_execute(VimState *state, int key)
                && (s->c == CAR || s->c == K_KENTER || s->c == NL)))
           && stop_arrow() == OK) {
         ins_compl_delete(false);
-        if (ins_compl_has_preinsert() && ins_compl_has_autocomplete()) {
+        if (ins_compl_has_preinsert() && ins_compl_autocomplete_enabled()) {
           (void)ins_compl_insert(false, true);
         } else {
           (void)ins_compl_insert(false, false);
@@ -851,7 +851,8 @@ static int insert_handle_key(InsertState *s)
   case Ctrl_H:
     s->did_backspace = ins_bs(s->c, BACKSPACE_CHAR, &s->inserted_space);
     auto_format(false, true);
-    if (s->did_backspace && p_ac && !char_avail() && curwin->w_cursor.col > 0) {
+    if (s->did_backspace && ins_compl_has_autocomplete() && !char_avail()
+        && curwin->w_cursor.col > 0) {
       s->c = char_before_cursor();
       if (vim_isprintc(s->c)) {
         redraw_later(curwin, UPD_VALID);
@@ -1238,7 +1239,7 @@ normalchar:
     // closed fold.
     foldOpenCursor();
     // Trigger autocompletion
-    if (p_ac && !char_avail() && vim_isprintc(s->c)) {
+    if (ins_compl_has_autocomplete() && !char_avail() && vim_isprintc(s->c)) {
       redraw_later(curwin, UPD_VALID);
       update_screen();  // Show character immediately
       ui_flush();

src/nvim/insexpand.c

@@ -2151,7 +2151,7 @@ bool ins_compl_preinsert_effect(void)
 }
 
 /// Returns true if autocompletion is active.
-bool ins_compl_has_autocomplete(void)
+bool ins_compl_autocomplete_enabled(void)
 {
   return compl_autocomplete;
 }
@@ -2227,6 +2227,13 @@ static bool ins_compl_need_restart(void)
   return compl_was_interrupted || ins_compl_refresh_always();
 }
 
+/// Return true if 'autocomplete' option is set
+bool ins_compl_has_autocomplete(void)
+{
+  // Use buffer-local setting if defined (>= 0), otherwise use global
+  return curbuf->b_p_ac >= 0 ? curbuf->b_p_ac : p_ac;
+}
+
 /// Called after changing "compl_leader".
 /// Show the popup menu with a different set of matches.
 /// May also search for matches again if the previous search was interrupted.
@@ -2256,9 +2263,7 @@ static void ins_compl_new_leader(void)
     // Matches were cleared, need to search for them now.
     // Set "compl_restarting" to avoid that the first match is inserted.
     compl_restarting = true;
-    if (p_ac) {
-      compl_autocomplete = true;
-    }
+    compl_autocomplete = ins_compl_has_autocomplete();
     if (ins_complete(Ctrl_N, true) == FAIL) {
       compl_cont_status = 0;
     }

src/nvim/option.c

@@ -384,6 +384,7 @@ void set_init_1(bool clean_arg)
   set_options_default(0);
 
   curbuf->b_p_initialized = true;
+  curbuf->b_p_ac = -1;
   curbuf->b_p_ar = -1;          // no local 'autoread' value
   curbuf->b_p_ul = NO_LOCAL_UNDOLEVEL;
   check_buf_options(curbuf);
@@ -3368,6 +3369,7 @@ static OptVal get_option_unset_value(OptIndex opt_idx)
     }
 
     switch (opt_idx) {
+    case kOptAutocomplete:
     case kOptAutoread:
       return BOOLEAN_OPTVAL(kNone);
     case kOptScrolloff:
@@ -4421,6 +4423,8 @@ void *get_varp_scope_from(vimoption_T *p, int opt_flags, buf_T *buf, win_T *win)
       return &(buf->b_p_kp);
     case kOptPath:
       return &(buf->b_p_path);
+    case kOptAutocomplete:
+      return &(buf->b_p_ac);
     case kOptAutoread:
       return &(buf->b_p_ar);
     case kOptTags:
@@ -4508,6 +4512,8 @@ void *get_varp_from(vimoption_T *p, buf_T *buf, win_T *win)
     return *buf->b_p_kp != NUL ? &buf->b_p_kp : p->var;
   case kOptPath:
     return *buf->b_p_path != NUL ? &(buf->b_p_path) : p->var;
+  case kOptAutocomplete:
+    return buf->b_p_ac >= 0 ? &(buf->b_p_ac) : p->var;
   case kOptAutoread:
     return buf->b_p_ar >= 0 ? &(buf->b_p_ar) : p->var;
   case kOptTags:
@@ -5204,6 +5210,7 @@ void buf_copy_options(buf_T *buf, int flags)
 
       // options that are normally global but also have a local value
       // are not copied, start using the global value
+      buf->b_p_ac = -1;
       buf->b_p_ar = -1;
       buf->b_p_ul = NO_LOCAL_UNDOLEVEL;
       buf->b_p_bkc = empty_string_option;

src/nvim/options.lua

@@ -236,7 +236,7 @@ local options = {
         |i_CTRL-N|, but triggered automatically.  See |ins-autocompletion|.
       ]=],
       full_name = 'autocomplete',
-      scope = { 'global' },
+      scope = { 'global', 'buf' },
       short_desc = N_('automatic completion in insert mode'),
       type = 'boolean',
       varname = 'p_ac',

test/functional/editor/completion_spec.lua

@@ -1416,7 +1416,7 @@ describe('completion', function()
     screen:try_resize(60, 10)
     source([[
       call setline(1, ['foo', 'foobar', 'foobarbaz'])
-      set autocomplete
+      setlocal autocomplete
     ]])
     screen:expect([[
       ^foo                                                         |

test/old/testdir/test_ins_complete.vim

@@ -5566,7 +5566,7 @@ func Test_scriptlocal_autoload_func()
   call Ntest_override("char_avail", 1)
   new
   inoremap <buffer> <F2> <Cmd>let b:matches = complete_info(["matches"]).matches<CR>
-  set autocomplete
+  setlocal autocomplete
 
   setlocal complete=.,Fcompl#Func
   call feedkeys("im\<F2>\<Esc>0", 'xt!')
@@ -5577,7 +5577,6 @@ func Test_scriptlocal_autoload_func()
   call assert_equal(['foo', 'foobar'], b:matches->mapnew('v:val.word'))
 
   setlocal complete&
-  set autocomplete&
   bwipe!
   call Ntest_override("char_avail", 0)
   let &rtp = save_rtp
@@ -5676,7 +5675,7 @@ func Test_autocompletedelay()
 
   let lines =<< trim [SCRIPT]
     call setline(1, ['foo', 'foobar', 'foobarbaz'])
-    set autocomplete
+    setlocal autocomplete
   [SCRIPT]
   call writefile(lines, 'XTest_autocomplete_delay', 'D')
   let buf = RunVimInTerminal('-S XTest_autocomplete_delay', {'rows': 10})