fix(lua): highlight.on_yank can close timer in twice #18976

check whether timer is closing in vim.defer_fn before closing

runtime/lua/vim/_editor.lua

@@ -373,9 +373,13 @@ end
 function vim.defer_fn(fn, timeout)
   vim.validate { fn = { fn, 'c', true}; }
   local timer = vim.loop.new_timer()
-  timer:start(timeout, 0, vim.schedule_wrap(function()
-    timer:stop()
-    timer:close()
+  timer:start(
+    timeout,
+    0,
+    vim.schedule_wrap(function()
+      if not timer:is_closing() then
+        timer:close()
+      end
 
     fn()
   end))

test/functional/lua/highlight_spec.lua

@@ -6,20 +6,29 @@ local command = helpers.command
 local clear = helpers.clear
 
 describe('vim.highlight.on_yank', function()
-
   before_each(function()
     clear()
   end)
 
   it('does not show errors even if buffer is wiped before timeout', function()
     command('new')
-    exec_lua[[
+    exec_lua([[
       vim.highlight.on_yank({timeout = 10, on_macro = true, event = {operator = "y", regtype = "v"}})
       vim.cmd('bwipeout!')
-    ]]
+    ]])
     helpers.sleep(10)
     helpers.feed('<cr>') -- avoid hang if error message exists
     eq('', eval('v:errmsg'))
   end)
 
+  it('does not close timer twice', function()
+    exec_lua([[
+      vim.highlight.on_yank({timeout = 10, on_macro = true, event = {operator = "y"}})
+      vim.loop.sleep(10)
+      vim.schedule(function()
+        vim.highlight.on_yank({timeout = 0, on_macro = true, event = {operator = "y"}})
+      end)
+    ]])
+    eq('', eval('v:errmsg'))
+  end)
 end)