patch 7.4.1691
Problem:    When switching to a new buffer and an autocommand applies syntax
            highlighting an ml_get error may occur.
Solution:   Check "syn_buf" against the buffer in the window. (Alexander von
            Buddenbrock, closes #676)
diff --git a/src/version.c b/src/version.c
index 3fa82ca..d08e730 100644
--- a/src/version.c
+++ b/src/version.c
@@ -749,6 +749,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1691,
+/**/
     1690,
 /**/
     1689,