vim-patch:9.1.1419: It is difficult to ignore all but some events (#34245)

Problem:  It is difficult to ignore all but some events.
Solution: Add support for a "-" prefix syntax in '(win)eventignore' that
          subtracts an event from the ignored set if present
          (Luuk van Baal).

8cc6d8b187

runtime/doc/options.txt

@@ -2392,6 +2392,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 	Otherwise this is a comma-separated list of event names.  Example: >vim
 	    set ei=WinEnter,WinLeave
 <
+	To ignore all but some events, a "-" prefix can be used: >vim
+	    :set ei=all,-WinLeave
+<
 
 					*'eventignorewin'* *'eiw'*
 'eventignorewin' 'eiw'	string	(default "")

runtime/lua/vim/_meta/options.lua

@@ -2047,6 +2047,12 @@ vim.go.efm = vim.go.errorformat
 ---     set ei=WinEnter,WinLeave
 --- ```
 ---
+--- To ignore all but some events, a "-" prefix can be used:
+---
+--- ```vim
+---     :set ei=all,-WinLeave
+--- ```
+---
 ---
 --- @type string
 vim.o.eventignore = ""

src/nvim/autocmd.c

@@ -661,15 +661,22 @@ const char *event_nr2name(event_T event)
 bool event_ignored(event_T event, char *ei)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
+  bool ignored = false;
   while (*ei != NUL) {
+    bool unignore = *ei == '-';
+    ei += unignore;
     if (STRNICMP(ei, "all", 3) == 0 && (ei[3] == NUL || ei[3] == ',')) {
-      return true;
+      ignored = ei == p_ei || event_names[event].event <= 0;
+      ei += 3 + (ei[3] == ',');
     } else if (event_name2nr(ei, &ei) == event) {
-      return true;
+      if (unignore) {
+        return false;
+      }
+      ignored = true;
     }
   }
 
-  return false;
+  return ignored;
 }
 
 /// Return OK when the contents of 'eventignore' or 'eventignorewin' is valid,
@@ -680,11 +687,9 @@ int check_ei(char *ei)
 
   while (*ei) {
     if (STRNICMP(ei, "all", 3) == 0 && (ei[3] == NUL || ei[3] == ',')) {
-      ei += 3;
-      if (*ei == ',') {
-        ei++;
-      }
+      ei += 3 + (ei[3] == ',');
     } else {
+      ei += (*ei == '-');
       event_T event = event_name2nr(ei, &ei);
       if (event == NUM_EVENTS || (win && event_names[event].event > 0)) {
         return FAIL;

src/nvim/options.lua

@@ -2699,6 +2699,9 @@ local options = {
         Otherwise this is a comma-separated list of event names.  Example: >vim
             set ei=WinEnter,WinLeave
         <
+        To ignore all but some events, a "-" prefix can be used: >vim
+            :set ei=all,-WinLeave
+        <
       ]=],
       expand_cb = 'expand_set_eventignore',
       full_name = 'eventignore',

src/nvim/optionstr.c

@@ -1110,12 +1110,20 @@ static bool expand_eiw = false;
 
 static char *get_eventignore_name(expand_T *xp, int idx)
 {
+  bool subtract = *xp->xp_pattern == '-';
   // 'eventignore(win)' allows special keyword "all" in addition to
   // all event names.
-  if (idx == 0) {
+  if (!subtract && idx == 0) {
     return "all";
   }
-  return get_event_name_no_group(xp, idx - 1, expand_eiw);
+
+  char *name = get_event_name_no_group(xp, idx - 1 + subtract, expand_eiw);
+  if (name == NULL) {
+    return NULL;
+  }
+
+  snprintf(IObuff, IOSIZE, "%s%s", subtract ? "-" : "", name);
+  return IObuff;
 }
 
 int expand_set_eventignore(optexpand_T *args, int *numMatches, char ***matches)

test/old/testdir/gen_opt_test.vim

@@ -226,9 +226,9 @@ let test_values = {
       \		['xxx']],
       \ 'eadirection': [['both', 'ver', 'hor'], ['xxx', 'ver,hor']],
       "\ 'encoding': [['latin1'], ['xxx', '']],
-      \ 'eventignore': [['', 'WinEnter', 'WinLeave,winenter', 'all,WinEnter'],
+      \ 'eventignore': [['', 'WinEnter', 'WinLeave,winenter', 'all,WinEnter', 'all,-WinLeave'],
       \		['xxx']],
-      \ 'eventignorewin': [['', 'WinEnter', 'WinLeave,winenter', 'all,WinEnter'],
+      \ 'eventignorewin': [['', 'WinEnter', 'WinLeave,winenter', 'all,WinEnter', 'all,-WinLeave'],
       \		['xxx', 'WinNew']],
       \ 'fileencoding': [['', 'latin1', 'xxx'], []],
       \ 'fileformat': [['dos', 'unix', 'mac'], ['xxx']],

test/old/testdir/test_autocmd.vim

@@ -4556,4 +4556,20 @@ func Test_reuse_curbuf_switch()
   %bw!
 endfunc
 
+func Test_eventignore_subtract()
+  set eventignore=all,-WinEnter
+  augroup testing
+    autocmd!
+    autocmd WinEnter * ++once let s:triggered = 1
+  augroup END
+
+  new
+  call assert_equal(1, s:triggered)
+
+  set eventignore&
+  unlet! s:triggered
+  call CleanUpTestAuGroup()
+  %bw!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

test/old/testdir/test_options.vim

@@ -597,6 +597,7 @@ func Test_set_completion_string_values()
 
   " Other string options that queries the system rather than fixed enum names
   call assert_equal(['all', 'BufAdd'], getcompletion('set eventignore=', 'cmdline')[0:1])
+  call assert_equal(['-BufAdd', '-BufCreate'], getcompletion('set eventignore=all,-', 'cmdline')[0:1])
   call assert_equal(['WinLeave', 'WinResized', 'WinScrolled'], getcompletion('set eiw=', 'cmdline')[-3:-1])
   call assert_equal('latin1', getcompletion('set fileencodings=', 'cmdline')[1])
   " call assert_equal('top', getcompletion('set printoptions=', 'cmdline')[0])