patch 9.1.1166: command-line auto-completion hard with wildmenu

Problem:  command-line auto-completion hard with wildmenu
Solution: implement "noselect" wildoption value (Girish Palya)

When `noselect` is present in `wildmode` and 'wildmenu' is enabled, the
completion menu appears without pre-selecting the first item.

This change makes it easier to implement command-line auto-completion,
where the menu dynamically appears as characters are typed, and `<Tab>`
can be used to manually select an item. This can be achieved by
leveraging the `CmdlineChanged` event to insert `wildchar(m)`,
triggering completion menu.

Without this change, auto-completion using the 'wildmenu' mechanism is
not feasible, as it automatically inserts the first match, preventing
dynamic selection.

The following Vimscript snippet demonstrates how to configure
auto-completion using `noselect`:

```vim
vim9script
set wim=noselect:lastused,full wop=pum wcm=<C-@> wmnu
autocmd CmdlineChanged : timer_start(0, function(CmdComplete, [getcmdline()]))

def CmdComplete(cur_cmdline: string, timer: number)
  var [cmdline, curpos] = [getcmdline(), getcmdpos()]
  if cur_cmdline ==# cmdline  # Avoid completing each character in keymaps and pasted text
    && !pumvisible() && curpos == cmdline->len() + 1

    if cmdline[curpos - 2] =~ '[\w*/:]'  # Reduce noise by completing only selected characters
      feedkeys("\<C-@>", "ti")
      set eventignore+=CmdlineChanged  # Suppress redundant completion attempts
      timer_start(0, (_) => {
        getcmdline()->substitute('\%x00$', '', '')->setcmdline()  # Remove <C-@> if no completion items exist
        set eventignore-=CmdlineChanged
      })
    endif
  endif
enddef
```

fixes: #16551
closes: #16759

Signed-off-by: Girish Palya <[email protected]>
Signed-off-by: Christian Brabandt <[email protected]>

Author: girishji

runtime/doc/options.txt

@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 9.1.  Last change: 2025 Mar 01
+*options.txt*	For Vim version 9.1.  Last change: 2025 Mar 02
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -9566,7 +9566,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 	"lastused"	When completing buffer names and more than one buffer
 			matches, sort buffers by time last used (other than
 			the current buffer).
-	When there is only a single match, it is fully completed in all cases.
+	"noselect"	Do not pre-select first menu item and start 'wildmenu'
+			if it is enabled.
+	When there is only a single match, it is fully completed in all cases
+	except when "noselect" is present.
 
 	Examples of useful colon-separated values:
 	"longest:full"	Like "longest", but also start 'wildmenu' if it is
@@ -9589,7 +9592,11 @@ A jump table for the options with a short description can be found at |Q_op|.
 		:set wildmode=list,full
 <	List all matches without completing, then each full match >
 		:set wildmode=longest,list
-<	Complete longest common string, then list alternatives.
+<	Complete longest common string, then list alternatives >
+		:set wildmode=noselect:full
+<	Display 'wildmenu' without completing, then each full match >
+		:set wildmode=noselect:lastused,full
+<	Same as above, but sort buffers by time last used.
 	More info here: |cmdline-completion|.
 
 						*'wildoptions'* *'wop'*

runtime/doc/version9.txt

@@ -1,4 +1,4 @@
-*version9.txt*  For Vim version 9.1.  Last change: 2025 Feb 23
+*version9.txt*  For Vim version 9.1.  Last change: 2025 Mar 02
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -41605,6 +41605,8 @@ Completion: ~
 	"preinsert"	- highlight to be inserted values
 - handle multi-line completion as expected
 - improved commandline completion for the |:hi| command
+- New option value for 'wildoptions':
+  	"noselect"	- do not auto select an entry in the wildmenu
 
 Options: ~
 - the default for 'commentstring' contains whitespace padding to have

src/cmdexpand.c

@@ -286,6 +286,9 @@ nextwild(
 	{
 	    int use_options = options |
 		    WILD_HOME_REPLACE|WILD_ADD_SLASH|WILD_SILENT;
+	    if (use_options & WILD_KEEP_SOLE_ITEM)
+		use_options &= ~WILD_KEEP_SOLE_ITEM;
+
 	    if (escape)
 		use_options |= WILD_ESCAPE;
 
@@ -340,7 +343,7 @@ nextwild(
 
     if (xp->xp_numfiles <= 0 && p2 == NULL)
 	beep_flush();
-    else if (xp->xp_numfiles == 1)
+    else if (xp->xp_numfiles == 1 && !(options & WILD_KEEP_SOLE_ITEM))
 	// free expanded pattern
 	(void)ExpandOne(xp, NULL, NULL, 0, WILD_FREE);
 

src/ex_getln.c

@@ -913,6 +913,8 @@ cmdline_wildchar_complete(
 
     if (wim_flags[wim_index] & WIM_BUFLASTUSED)
 	options |= WILD_BUFLASTUSED;
+    if (wim_flags[0] & WIM_NOSELECT)
+	options |= WILD_KEEP_SOLE_ITEM;
     if (xp->xp_numfiles > 0)   // typed p_wc at least twice
     {
 	// if 'wildmode' contains "list" may still need to list
@@ -958,14 +960,15 @@ cmdline_wildchar_complete(
 	// when more than one match, and 'wildmode' first contains
 	// "list", or no change and 'wildmode' contains "longest,list",
 	// list all matches
-	if (res == OK && xp->xp_numfiles > 1)
+	if (res == OK
+		&& xp->xp_numfiles > ((wim_flags[wim_index] & WIM_NOSELECT) ? 0 : 1))
 	{
 	    // a "longest" that didn't do anything is skipped (but not
 	    // "list:longest")
 	    if (wim_flags[0] == WIM_LONGEST && ccline.cmdpos == j)
 		wim_index = 1;
 	    if ((wim_flags[wim_index] & WIM_LIST)
-		    || (p_wmnu && (wim_flags[wim_index] & WIM_FULL) != 0))
+		    || (p_wmnu && (wim_flags[wim_index] & (WIM_FULL | WIM_NOSELECT))))
 	    {
 		if (!(wim_flags[0] & WIM_LONGEST))
 		{
@@ -974,7 +977,7 @@ cmdline_wildchar_complete(
 		    p_wmnu = 0;
 
 		    // remove match
-		    nextwild(xp, WILD_PREV, 0, escape);
+		    nextwild(xp, WILD_PREV, 0 | (options & ~WIM_NOSELECT), escape);
 		    p_wmnu = p_wmnu_save;
 		}
 		(void)showmatches(xp, p_wmnu
@@ -983,7 +986,8 @@ cmdline_wildchar_complete(
 		*did_wild_list = TRUE;
 		if (wim_flags[wim_index] & WIM_LONGEST)
 		    nextwild(xp, WILD_LONGEST, options, escape);
-		else if (wim_flags[wim_index] & WIM_FULL)
+		else if ((wim_flags[wim_index] & WIM_FULL)
+			&& !(wim_flags[wim_index] & WIM_NOSELECT))
 		    nextwild(xp, WILD_NEXT, options, escape);
 	    }
 	    else
@@ -2716,6 +2720,8 @@ check_opt_wim(void)
 	    new_wim_flags[idx] |= WIM_LIST;
 	else if (i == 8 && STRNCMP(p, "lastused", 8) == 0)
 	    new_wim_flags[idx] |= WIM_BUFLASTUSED;
+	else if (i == 8 && STRNCMP(p, "noselect", 8) == 0)
+	    new_wim_flags[idx] |= WIM_NOSELECT;
 	else
 	    return FAIL;
 	p += i;

src/option.h

@@ -369,6 +369,7 @@ typedef enum {
 #define WIM_LONGEST	0x02
 #define WIM_LIST	0x04
 #define WIM_BUFLASTUSED	0x08
+#define WIM_NOSELECT	0x10
 
 // flags for the 'wildoptions' option
 // each defined char should be unique over all values.

src/optionstr.c

@@ -94,7 +94,7 @@ static char *(p_ttym_values[]) = {"xterm", "xterm2", "dec", "netterm", "jsbterm"
 #endif
 static char *(p_ve_values[]) = {"block", "insert", "all", "onemore", "none", "NONE", NULL};
 // Note: Keep this in sync with check_opt_wim()
-static char *(p_wim_values[]) = {"full", "longest", "list", "lastused", NULL};
+static char *(p_wim_values[]) = {"full", "longest", "list", "lastused", "noselect", NULL};
 static char *(p_wop_values[]) = {"fuzzy", "tagfile", "pum", NULL};
 #ifdef FEAT_WAK
 static char *(p_wak_values[]) = {"yes", "menu", "no", NULL};

src/testdir/gen_opt_test.vim

@@ -321,6 +321,7 @@ let test_values = {
       \		'bs'],
       \		['xxx']],
       \ 'wildmode': [['', 'full', 'longest', 'list', 'lastused', 'list:full',
+      \		'noselect', 'noselect,full', 'noselect:lastused,full',
       \		'full,longest', 'full,full,full,full'],
       \		['xxx', 'a4', 'full,full,full,full,full']],
       \ 'wildoptions': [['', 'tagfile', 'pum', 'fuzzy'], ['xxx']],

src/testdir/test_cmdline.vim

@@ -2170,16 +2170,52 @@ func Wildmode_tests()
   call assert_equal('AAA    AAAA   AAAAA', g:Sline)
   call assert_equal('"b A', @:)
 
+  " When 'wildmenu' is not set, 'noselect' completes first item
+  set wildmode=noselect
+  call feedkeys(":MyCmd o\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd oneA', @:)
+
+  " When 'noselect' is present, do not complete first <tab>.
+  set wildmenu
+  set wildmode=noselect
+  call feedkeys(":MyCmd o\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd o', @:)
+  call feedkeys(":MyCmd o\t\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd o', @:)
+  call feedkeys(":MyCmd o\t\t\<C-Y>\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd o', @:)
+
+  " When 'full' is present, complete after first <tab>.
+  set wildmode=noselect,full
+  call feedkeys(":MyCmd o\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd o', @:)
+  call feedkeys(":MyCmd o\t\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd oneA', @:)
+  call feedkeys(":MyCmd o\t\t\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd oneB', @:)
+  call feedkeys(":MyCmd o\t\t\t\<C-Y>\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd oneB', @:)
+
+  " 'noselect' has no effect when 'longest' is present.
+  set wildmode=noselect:longest
+  call feedkeys(":MyCmd o\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd one', @:)
+
+  " Complete 'noselect' value in 'wildmode' option
+  set wildmode&
+  call feedkeys(":set wildmode=n\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"set wildmode=noselect', @:)
+  call feedkeys(":set wildmode=\t\t\t\t\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"set wildmode=noselect', @:)
+
   " when using longest completion match, matches shorter than the argument
   " should be ignored (happens with :help)
   set wildmode=longest,full
-  set wildmenu
   call feedkeys(":help a*\t\<C-B>\"\<CR>", 'xt')
   call assert_equal('"help a', @:)
   " non existing file
   call feedkeys(":e a1b2y3z4\t\<C-B>\"\<CR>", 'xt')
   call assert_equal('"e a1b2y3z4', @:)
-  set wildmenu&
 
   " Test for longest file name completion with 'fileignorecase'
   " On MS-Windows, file names are case insensitive.
@@ -2199,6 +2235,21 @@ func Wildmode_tests()
     set fileignorecase&
   endif
 
+  " If 'noselect' is present, single item menu should not insert item
+  func! T(a, c, p)
+    return "oneA"
+  endfunc
+  command! -nargs=1 -complete=custom,T MyCmd
+  set wildmode=noselect,full
+  call feedkeys(":MyCmd o\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd o', @:)
+  call feedkeys(":MyCmd o\t\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd oneA', @:)
+  " 'nowildmenu' should make 'noselect' ineffective
+  set nowildmenu
+  call feedkeys(":MyCmd o\t\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"MyCmd oneA', @:)
+
   %argdelete
   delcommand MyCmd
   delfunc T

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1166,
 /**/
     1165,
 /**/

src/vim.h

@@ -881,6 +881,7 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 #define WILD_NOERROR		    0x800  // sets EW_NOERROR
 #define WILD_BUFLASTUSED	    0x1000
 #define BUF_DIFF_FILTER		    0x2000
+#define WILD_KEEP_SOLE_ITEM	    0x4000
 
 // Flags for expand_wildcards()
 #define EW_DIR		0x01	// include directory names