vim-patch:9.1.1679: unclear what key causes CmdlineLeave autocommand (neovim#35677)

Problem:  unclear what key causes CmdlineLeave autocommand
Solution: Set |v:char| to the key (Girish Palya).

related: vim/vim#17806
closes: vim/vim#18063

vim/vim@ba9551d

Co-authored-by: Girish Palya <[email protected]>

Author: zeertzjq

runtime/doc/autocmd.txt

@@ -400,6 +400,8 @@ CmdlineLeave			Before leaving the command-line (including
 				non-interactive use of ":" in a mapping: use
 				|<Cmd>| instead to avoid this).
 				<afile> expands to the |cmdline-char|.
+				Sets the |v:char| to the key that exited the
+				command-line (e.g. <CR>, <CTRL-C>, <Esc>).
 				Sets these |v:event| keys:
 				    abort (mutable)
 				    cmdlevel
@@ -417,6 +419,7 @@ CmdlineLeavePre			Just before leaving the command line, and
 				not when using |<Cmd>|.  Also triggered when
 				abandoning the command line by typing CTRL-C
 				or <Esc>.  <afile> is set to |cmdline-char|.
+				Sets |v:char| as with |CmdlineLeave|.
 							*CmdwinEnter*
 CmdwinEnter			After entering the command-line window.
 				Useful for setting options specifically for

runtime/doc/news.txt

@@ -196,6 +196,7 @@ EDITOR
 
 EVENTS
 
+• |CmdlineLeave| sets |v:char| to the character that stops the Cmdline mode.
 • |CmdlineLeavePre| triggered before preparing to leave the command line.
 • New `append` paremeter for |ui-messages| `msg_show` event.
 • New `msg_id` paremeter for |ui-messages| `msg_show` event.

runtime/doc/vvars.txt

@@ -21,7 +21,8 @@ v:argv
 v:char
 		Argument for evaluating 'formatexpr' and used for the typed
 		character when using <expr> in an abbreviation |:map-<expr>|.
-		It is also used by the |InsertCharPre| and |InsertEnter| events.
+		It is also used by the |InsertCharPre|, |InsertEnter|,
+		|CmdlineLeave| and |CmdlineLeavePre| events.
 
 			*v:charconvert_from* *charconvert_from-variable*
 v:charconvert_from

runtime/lua/vim/_meta/vvars.lua

@@ -897,6 +897,7 @@ static uint8_t *command_line_enter(int firstc, int count, int indent, bool clear
 
   // Trigger CmdlineLeavePre autocommands if not already triggered.
   if (!s->event_cmdlineleavepre_triggered) {
+    set_vim_var_char(s->c);  // Set v:char
     trigger_cmd_autocmd(s->cmdline_type, EVENT_CMDLINELEAVEPRE);
   }
 
@@ -910,6 +911,7 @@ static uint8_t *command_line_enter(int firstc, int count, int indent, bool clear
     // not readonly:
     tv_dict_add_bool(dict, S_LEN("abort"),
                      s->gotesc ? kBoolVarTrue : kBoolVarFalse);
+    set_vim_var_char(s->c);  // Set v:char
     TRY_WRAP(&err, {
       apply_autocmds(EVENT_CMDLINELEAVE, firstcbuf, firstcbuf, false, curbuf);
       // error printed below, to avoid redraw issues
@@ -1361,6 +1363,7 @@ static int command_line_execute(VimState *state, int key)
   // Trigger CmdlineLeavePre autocommand
   if ((KeyTyped && (s->c == '\n' || s->c == '\r' || s->c == K_KENTER || s->c == ESC))
       || s->c == Ctrl_C) {
+    set_vim_var_char(s->c);  // Set v:char
     trigger_cmd_autocmd(s->cmdline_type, EVENT_CMDLINELEAVEPRE);
     s->event_cmdlineleavepre_triggered = true;
     if ((s->c == ESC || s->c == Ctrl_C) && (wim_flags[0] & kOptWimFlagList)) {

src/nvim/ex_getln.c

@@ -14,7 +14,8 @@ M.vars = {
     desc = [=[
       Argument for evaluating 'formatexpr' and used for the typed
       character when using <expr> in an abbreviation |:map-<expr>|.
-      It is also used by the |InsertCharPre| and |InsertEnter| events.
+      It is also used by the |InsertCharPre|, |InsertEnter|,
+      |CmdlineLeave| and |CmdlineLeavePre| events.
     ]=],
   },
   charconvert_from = {

src/nvim/vvars.lua

@@ -4967,4 +4967,23 @@ func Test_long_line_noselect()
   call StopVimInTerminal(buf)
 endfunc
 
+func Test_CmdlineLeave_vchar_keys()
+  func OnLeave()
+    let g:leave_key = v:char
+  endfunction
+
+  new
+  for event in ["CmdlineLeavePre", "CmdlineLeave"]
+    exec "autocmd" event "* :call OnLeave()"
+    for key in ["\<C-C>", "\<Esc>", "\<CR>"]
+      call feedkeys($":echo{key}", 'tx')
+      call assert_equal(key, g:leave_key)
+    endfor
+    exec "autocmd!" event
+  endfor
+  bwipe!
+  delfunc OnLeave
+  unlet g:leave_key
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab