patch 7.4.2309
Problem:    Crash when doing tabnext in a BufUnload autocmd. (Dominique Pelle)
Solution:   When detecting that the tab page changed, don't just abort but
            delete the window where w_buffer is NULL.
diff --git a/src/version.c b/src/version.c
index f5af115..5fd33ec 100644
--- a/src/version.c
+++ b/src/version.c
@@ -764,6 +764,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2309,
+/**/
     2308,
 /**/
     2307,