patch 9.1.1679: unclear what key causes CmdlineLeave autocommand

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

related: #17806
closes: #18063

Signed-off-by: Girish Palya <girishji@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/autocmd.txt

@@ -1,4 +1,4 @@
-*autocmd.txt*   For Vim version 9.1.  Last change: 2025 Jun 19
+*autocmd.txt*   For Vim version 9.1.  Last change: 2025 Aug 23
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -644,6 +644,8 @@ CmdlineLeave			Before leaving the command line; including
 				<afile> is set to a single character,
 				indicating the type of command-line.
 				|cmdwin-char|
+				Sets the |v:char| to the key that exited the
+				command-line (e.g. <CR>, <CTRL-C>, <Esc>).
 							*CmdlineLeavePre*
 CmdlineLeavePre			Just before leaving the command line, and
 				before |CmdlineLeave|.  Useful for capturing
@@ -656,6 +658,7 @@ CmdlineLeavePre			Just before leaving the command line, and
 				or <Esc>.  <afile> is set to a single
 				character indicating the command-line type.
 				See |cmdwin-char| for details.
+				Sets |v:char| as with |CmdlineLeave|.
 							*CmdwinEnter*
 CmdwinEnter			After entering the command-line window.
 				Useful for setting options specifically for

runtime/doc/eval.txt

@@ -2227,8 +2227,8 @@ v:beval_winid	The |window-ID| of the window, over which the mouse pointer
 					*v:char* *char-variable*
 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|, |InsertEnter| and
+		It is also used by the |InsertCharPre|, |InsertEnter|,
-		|KeyInputPre| events.
+		|KeyInputPre|, |CmdlineLeave| and |CmdlineLeavePre| events.
 
 			*v:charconvert_from* *charconvert_from-variable*
 v:charconvert_from

runtime/doc/version9.txt

@@ -41750,6 +41750,8 @@ Others: ~
   ANGLE BRACKET "]>".
 - Support for Unix domain sockets have been added for the clientserver
   feature, see |socketserver-clientserver|.
+- |CmdlineLeave| sets |v:char| to the character that caused exiting the
+  Command-line.
 
 Platform specific ~
 - MS-Winodws: Paths like "\Windows" and "/Windows" are now considered to be

src/ex_getln.c

@@ -1980,6 +1980,9 @@ getcmdline_int(
 #endif
 		    || c == Ctrl_C))
 	{
+#ifdef FEAT_EVAL
+	    set_vim_var_char(c);  // Set v:char
+#endif
 	    trigger_cmd_autocmd(cmdline_type, EVENT_CMDLINELEAVEPRE);
 	    event_cmdlineleavepre_triggered = TRUE;
 #if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
@@ -2646,7 +2649,12 @@ cmdline_changed:
 returncmd:
     // Trigger CmdlineLeavePre autocommands if not already triggered.
     if (!event_cmdlineleavepre_triggered)
+    {
+#ifdef FEAT_EVAL
+	set_vim_var_char(c);  // Set v:char
+#endif
 	trigger_cmd_autocmd(cmdline_type, EVENT_CMDLINELEAVEPRE);
+    }
 
 #ifdef FEAT_RIGHTLEFT
     cmdmsg_rl = FALSE;
@@ -2704,6 +2712,9 @@ returncmd:
 	need_wait_return = FALSE;
 
     // Trigger CmdlineLeave autocommands.
+#ifdef FEAT_EVAL
+    set_vim_var_char(c);  // Set v:char
+#endif
     trigger_cmd_autocmd(cmdline_type, EVENT_CMDLINELEAVE);
 
     State = save_State;

src/proto/cmdexpand.pro

@@ -25,5 +25,5 @@ int wildmenu_process_key(cmdline_info_T *cclp, int key, expand_T *xp);
 void wildmenu_cleanup(cmdline_info_T *cclp);
 void f_getcompletion(typval_T *argvars, typval_T *rettv);
 void f_getcompletiontype(typval_T *argvars, typval_T *rettv);
-void f_cmdcomplete_info(typval_T *argvars, typval_T *rettv);
+void f_cmdcomplete_info(typval_T *argvars UNUSED, typval_T *rettv);
 /* vim: set ft=c : */

src/testdir/test_cmdline.vim

@@ -4918,4 +4918,23 @@ 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

src/version.c

@@ -724,6 +724,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1679,
 /**/
     1678,
 /**/