fix(events): trigger VimResume on next UI request (#24426)

src/nvim/api/ui.c

@@ -215,6 +215,8 @@ void nvim_ui_attach(uint64_t channel_id, Integer width, Integer height, Dictiona
 
   pmap_put(uint64_t)(&connected_uis, channel_id, ui);
   ui_attach_impl(ui, channel_id);
+
+  may_trigger_vim_suspend_resume(false);
 }
 
 /// @deprecated
@@ -237,6 +239,10 @@ void nvim_ui_set_focus(uint64_t channel_id, Boolean gained, Error *error)
     return;
   }
 
+  if (gained) {
+    may_trigger_vim_suspend_resume(false);
+  }
+
   do_autocmd_focusgained((bool)gained);
 }
 

src/nvim/api/vim.c

@@ -305,6 +305,7 @@ void nvim_feedkeys(String keys, String mode, Boolean escape_ks)
 Integer nvim_input(String keys)
   FUNC_API_SINCE(1) FUNC_API_FAST
 {
+  may_trigger_vim_suspend_resume(false);
   return (Integer)input_enqueue(keys);
 }
 
@@ -334,6 +335,8 @@ void nvim_input_mouse(String button, String action, String modifier, Integer gri
                       Integer col, Error *err)
   FUNC_API_SINCE(6) FUNC_API_FAST
 {
+  may_trigger_vim_suspend_resume(false);
+
   if (button.data == NULL || action.data == NULL) {
     goto error;
   }

src/nvim/autocmd.c

@@ -46,6 +46,7 @@
 #include "nvim/search.h"
 #include "nvim/state.h"
 #include "nvim/strings.h"
+#include "nvim/types.h"
 #include "nvim/ui.h"
 #include "nvim/ui_compositor.h"
 #include "nvim/vim.h"
@@ -2521,6 +2522,30 @@ static bool arg_autocmd_flag_get(bool *flag, char **cmd_ptr, char *pattern, int
   return false;
 }
 
+/// When kFalse: VimSuspend should be triggered next.
+/// When kTrue: VimResume should be triggerd next.
+/// When kNone: Currently triggering VimSuspend or VimResume.
+static TriState pending_vimresume = kFalse;
+
+static void vimresume_event(void **argv)
+{
+  apply_autocmds(EVENT_VIMRESUME, NULL, NULL, false, NULL);
+  pending_vimresume = kFalse;
+}
+
+/// Trigger VimSuspend or VimResume autocommand.
+void may_trigger_vim_suspend_resume(bool suspend)
+{
+  if (suspend && pending_vimresume == kFalse) {
+    pending_vimresume = kNone;
+    apply_autocmds(EVENT_VIMSUSPEND, NULL, NULL, false, NULL);
+    pending_vimresume = kTrue;
+  } else if (!suspend && pending_vimresume == kTrue) {
+    pending_vimresume = kNone;
+    multiqueue_put(main_loop.events, vimresume_event, 0);
+  }
+}
+
 // UI Enter
 void do_autocmd_uienter(uint64_t chanid, bool attached)
 {

src/nvim/ex_docmd.c

@@ -4874,12 +4874,9 @@ static void ex_stop(exarg_T *eap)
   if (!eap->forceit) {
     autowrite_all();
   }
-  apply_autocmds(EVENT_VIMSUSPEND, NULL, NULL, false, NULL);
-
+  may_trigger_vim_suspend_resume(true);
   ui_call_suspend();
   ui_flush();
-
-  apply_autocmds(EVENT_VIMRESUME, NULL, NULL, false, NULL);
 }
 
 /// ":exit", ":xit" and ":wq": Write file and quit the current window.

test/functional/api/ui_spec.lua

@@ -1,8 +1,11 @@
 local helpers = require('test.functional.helpers')(after_each)
 local Screen = require('test.functional.ui.screen')
 local clear = helpers.clear
+local command = helpers.command
 local eq = helpers.eq
 local eval = helpers.eval
+local exec = helpers.exec
+local feed = helpers.feed
 local meths = helpers.meths
 local request = helpers.request
 local pcall_err = helpers.pcall_err
@@ -76,3 +79,59 @@ it('autocmds UIEnter/UILeave', function()
     'UILeave',
   }, eval('g:evs'))
 end)
+
+it('autocmds VimSuspend/VimResume #22041', function()
+  clear()
+  local screen = Screen.new()
+  screen:attach()
+  exec([[
+    let g:ev = []
+    autocmd VimResume  * :call add(g:ev, 'r')
+    autocmd VimSuspend * :call add(g:ev, 's')
+  ]])
+
+  eq(false, screen.suspended)
+  feed('<C-Z>')
+  screen:expect(function() eq (true, screen.suspended) end)
+  eq({ 's' }, eval('g:ev'))
+  screen.suspended = false
+  feed('<Ignore>')
+  eq({ 's', 'r' }, eval('g:ev'))
+
+  command('suspend')
+  screen:expect(function() eq (true, screen.suspended) end)
+  eq({ 's', 'r', 's' }, eval('g:ev'))
+  screen.suspended = false
+  meths.input_mouse('move', '', '', 0, 0, 0)
+  eq({ 's', 'r', 's', 'r' }, eval('g:ev'))
+
+  feed('<C-Z>')
+  screen:expect(function() eq (true, screen.suspended) end)
+  meths.ui_set_focus(false)
+  eq({ 's', 'r', 's', 'r', 's' }, eval('g:ev'))
+  screen.suspended = false
+  meths.ui_set_focus(true)
+  eq({ 's', 'r', 's', 'r', 's', 'r' }, eval('g:ev'))
+
+  command('suspend')
+  screen:expect(function() eq (true, screen.suspended) end)
+  screen:detach()
+  eq({ 's', 'r', 's', 'r', 's', 'r', 's' }, eval('g:ev'))
+  screen.suspended = false
+  screen:attach()
+  eq({ 's', 'r', 's', 'r', 's', 'r', 's', 'r' }, eval('g:ev'))
+
+  eq(false, screen.suspended)
+  feed('<C-Z><C-Z><C-Z><C-Z>')
+  screen:expect(function() eq (true, screen.suspended) end)
+  eq({ 's', 'r', 's', 'r', 's', 'r', 's', 'r', 's' }, eval('g:ev'))
+  screen.suspended = false
+  feed('<C-Z><C-Z><C-Z><C-Z>')
+  eq({ 's', 'r', 's', 'r', 's', 'r', 's', 'r', 's', 'r', 's' }, eval('g:ev'))
+  screen:expect(function() eq (true, screen.suspended) end)
+  screen.suspended = false
+  feed('i<C-R>=g:ev<CR>')
+  eq({ 's', 'r', 's', 'r', 's', 'r', 's', 'r', 's', 'r', 's', 'r' }, eval('g:ev'))
+  eq({ 's', 'r', 's', 'r', 's', 'r', 's', 'r', 's', 'r', 's', 'r', '' },
+     meths.buf_get_lines(0, 0, -1, true))
+end)

test/functional/ui/screen_basic_spec.lua

@@ -4,7 +4,6 @@ local spawn, set_session, clear = helpers.spawn, helpers.set_session, helpers.cl
 local feed, command = helpers.feed, helpers.command
 local insert = helpers.insert
 local eq = helpers.eq
-local eval = helpers.eval
 local funcs, meths = helpers.funcs, helpers.meths
 
 describe('screen', function()
@@ -64,34 +63,6 @@ local function screen_tests(linegrid)
     } )
   end)
 
-  describe(':suspend', function()
-    it('is forwarded to the UI', function()
-      local function check()
-        eq(true, screen.suspended)
-      end
-
-      command('let g:ev = []')
-      command('autocmd VimResume  * :call add(g:ev, "r")')
-      command('autocmd VimSuspend * :call add(g:ev, "s")')
-
-      eq(false, screen.suspended)
-      command('suspend')
-      eq({ 's', 'r' }, eval('g:ev'))
-
-      screen:expect(check)
-      screen.suspended = false
-
-      feed('<c-z>')
-      eq({ 's', 'r', 's', 'r' }, eval('g:ev'))
-
-      screen:expect(check)
-      screen.suspended = false
-
-      command('suspend')
-      eq({ 's', 'r', 's', 'r', 's', 'r' }, eval('g:ev'))
-    end)
-  end)
-
   describe('bell/visual bell', function()
     it('is forwarded to the UI', function()
       feed('<left>')