patch 7.4.1837
Problem:    The BufUnload event is triggered twice, when :bunload is used with
             set to  or .
Solution:   Do not trigger the event when ml_mfp is NULL. (Hirohito Higashi)
diff --git a/src/version.c b/src/version.c
index 8b92714..f1bbbdd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1837,
+/**/
     1836,
 /**/
     1835,