commit https://github.com/vim/vim/commit/4231da403e3c879dd6ac261e51f4ca60813935e3 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jun 2 14:30:04 2016 +0200 patch 7.4.1873 Problem: When a callback adds a timer the GUI doesn't use it until later. (Ramel Eshed) Solution: Return early if a callback adds a timer.

--- a/src/globals.h
+++ b/src/globals.h
@@ -1635,6 +1635,10 @@ EXTERN int  disable_char_avail_for_testi
 EXTERN int  in_free_unref_items INIT(= FALSE);
 #endif
 
+#ifdef FEAT_TIMERS
+EXTERN int  did_add_timer INIT(= FALSE);
+#endif
+
 /*
  * Optional Farsi support.  Include it here, so EXTERN and INIT are defined.
  */