vim-patch:9.1.0511: CursorMovedC triggered wrongly with setcmdpos()

Problem:  CursorMovedC triggered wrongly with setcmdpos()
          (after v9.1.0507)
Solution: Remove the premature triggering.  Also don't trigger when
          cursor didn't move. (zeertzjq)

closes: vim/vim#15064

bc6f96708e

runtime/doc/autocmd.txt

@@ -524,7 +524,8 @@ CursorMoved			After the cursor was moved in Normal or Visual
 				that is slow.
 							*CursorMovedC*
 CursorMovedC			After the cursor was moved in the command
-				line. Be careful not to mess up the
+				line while the text in the command line hasn't
+				changed.  Be careful not to mess up the
 				command line, it may cause Vim to lock up.
 				<afile> is set to a single character,
 				indicating the type of command-line.

src/nvim/ex_getln.c

@@ -134,7 +134,7 @@ typedef struct {
   int wim_index;                        // index in wim_flags[]
   int save_msg_scroll;
   int save_State;                       // remember State when called
-  int save_cmdspos;
+  int prev_cmdpos;
   char *save_p_icm;
   int some_key_typed;                   // one of the keys was typed
   // mouse drag and release events are ignored, unless they are
@@ -691,7 +691,7 @@ static uint8_t *command_line_enter(int firstc, int count, int indent, bool clear
     .indent = indent,
     .save_msg_scroll = msg_scroll,
     .save_State = State,
-    .save_cmdspos = ccline.cmdspos,
+    .prev_cmdpos = -1,
     .ignore_drag_release = true,
   };
   CommandLineState *s = &state;
@@ -2184,10 +2184,10 @@ static int command_line_handle_key(CommandLineState *s)
 static int command_line_not_changed(CommandLineState *s)
 {
   // Trigger CursorMovedC autocommands.
-  if (ccline.cmdspos != s->save_cmdspos) {
+  if (ccline.cmdpos != s->prev_cmdpos) {
     trigger_cmd_autocmd(get_cmdline_type(), EVENT_CURSORMOVEDC);
+    s->prev_cmdpos = ccline.cmdpos;
   }
-
   // Incremental searches for "/" and "?":
   // Enter command_line_not_changed() when a character has been read but the
   // command line did not change. Then we only search and redraw if something
@@ -2662,6 +2662,7 @@ static void do_autocmd_cmdlinechanged(int firstc)
 
 static int command_line_changed(CommandLineState *s)
 {
+  s->prev_cmdpos = ccline.cmdpos;
   // Trigger CmdlineChanged autocommands.
   do_autocmd_cmdlinechanged(s->firstc > 0 ? s->firstc : '-');
 
@@ -4191,9 +4192,6 @@ static int set_cmdline_pos(int pos)
     new_cmdpos = pos;
   }
 
-  // Trigger CursorMovedC autocommands.
-  trigger_cmd_autocmd(get_cmdline_type(), EVENT_CURSORMOVEDC);
-
   return 0;
 }
 

test/old/testdir/test_autocmd.vim

@@ -2011,20 +2011,28 @@ func Test_Cmdline()
   au! CmdlineLeave
   let &shellslash = save_shellslash
 
-  au! CursorMovedC : let g:pos = getcmdpos()
+  au! CursorMovedC : let g:pos += [getcmdpos()]
-  let g:pos = 0
+  let g:pos = []
-  call feedkeys(":hello\<Left>\<ESC>", 'xt')
+  call feedkeys(":hello\<Left>\<C-R>=''\<CR>\<Left>\<Right>\<Esc>", 'xt')
-  call assert_equal(5, g:pos)
+  call assert_equal([5, 4, 5], g:pos)
-  call feedkeys(":12345678\<C-R>=setcmdpos(3)\<CR>\<ESC>", 'xt')
+  let g:pos = []
-  call assert_equal(3, g:pos)
+  call feedkeys(":12345678\<C-R>=setcmdpos(3)??''\<CR>\<Esc>", 'xt')
+  call assert_equal([3], g:pos)
+  let g:pos = []
+  call feedkeys(":12345678\<C-R>=setcmdpos(3)??''\<CR>\<Left>\<Esc>", 'xt')
+  call assert_equal([3, 2], g:pos)
   au! CursorMovedC
 
-  " CursorMovedC changes the cursor position.
+  " setcmdpos() is no-op inside an autocommand
-  au! CursorMovedC : let g:pos = getcmdpos() | call setcmdpos(getcmdpos()-1)
+  au! CursorMovedC : let g:pos += [getcmdpos()] | call setcmdpos(1)
-  let g:pos = 0
+  let g:pos = []
-  call feedkeys(":hello\<Left>\<ESC>", 'xt')
+  call feedkeys(":hello\<Left>\<Left>\<Esc>", 'xt')
-  call assert_equal(5, g:pos)
+  call assert_equal([5, 4], g:pos)
   au! CursorMovedC
+
+  unlet g:entered
+  unlet g:left
+  unlet g:pos
 endfunc
 
 " Test for BufWritePre autocommand that deletes or unloads the buffer.