commit https://github.com/vim/vim/commit/e3188e261569ae512fb1ae2653b57fdd9e259ca3 Author: Bram Moolenaar <Bram@vim.org> Date: Tue May 31 21:13:04 2016 +0200 patch 7.4.1860 Problem: Using a partial for timer_start() may cause a crash. Solution: Set the copyID in timer objects. (Ozaki Kiichi)

--- a/src/eval.c
+++ b/src/eval.c
@@ -7046,6 +7046,10 @@ garbage_collect(int testing)
     abort = abort || set_ref_in_nb_channel(copyID);
 #endif
 
+#ifdef FEAT_TIMERS
+    abort = abort || set_ref_in_timer(copyID);
+#endif
+
     if (!abort)
     {
 	/*