vim-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: vim/vim#16551
closes: vim/vim#16759

https://github.com/vim/vim/commit/2bacc3e5fb3569e0fd98e129cb1e422ca18b80a6

Cherry-pick Wildmode_Tests() change from patch 9.0.0418.

Co-authored-by: Girish Palya <girishji@gmail.com>
Signed-off-by: Tomas Slusny <slusnucky@gmail.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index d1d5a56082..2516d1a970 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -10020,7 +10020,7 @@ local options = {
       cb = 'did_set_wildmode',
       defaults = 'full',
       -- Keep this in sync with check_opt_wim().
-      values = { 'full', 'longest', 'list', 'lastused' },
+      values = { 'full', 'longest', 'list', 'lastused', 'noselect' },
       flags = true,
       deny_duplicates = false,
       desc = [=[
@@ -10042,7 +10042,10 @@ local options = {
         "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
@@ -10065,7 +10068,11 @@ local options = {
         	set wildmode=list,full
         <	List all matches without completing, then each full match >vim
         	set wildmode=longest,list
-        <	Complete longest common string, then list alternatives.
+        <	Complete longest common string, then list alternatives >vim
+        	set wildmode=noselect:full
+        <	Display 'wildmenu' without completing, then each full match >vim
+        	set wildmode=noselect:lastused,full
+        <	Same as above, but sort buffers by time last used.
         More info here: |cmdline-completion|.
       ]=],
       full_name = 'wildmode',