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, 15 insertions, 2 deletions

diff --git a/runtime/lua/vim/_meta/options.lua b/runtime/lua/vim/_meta/options.lua
index 8df174a838..8e6acecc28 100644
--- a/runtime/lua/vim/_meta/options.lua
+++ b/runtime/lua/vim/_meta/options.lua
@@ -7691,7 +7691,10 @@ vim.go.wmnu = vim.go.wildmenu
 --- "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
@@ -7729,7 +7732,17 @@ vim.go.wmnu = vim.go.wildmenu
 --- ```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`.
 ---
 --- @type string