patch 8.0.1561: crash with rust syntax highligting

Problem:    Crash with rust syntax highligting. (Edd Barrett)
Solution:   Avoid going past the end of an empty line.
diff --git a/src/syntax.c b/src/syntax.c
index 81f4604..d0d4515 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -2470,7 +2470,8 @@
 
     /* nextgroup ends at end of line, unless "skipnl" or "skipempty" present */
     if (current_next_list != NULL
-	    && syn_getcurline()[current_col + 1] == NUL
+	    && (line = syn_getcurline())[current_col] != NUL
+	    && line[current_col + 1] == NUL
 	    && !(current_next_flags & (HL_SKIPNL | HL_SKIPEMPTY)))
 	current_next_list = NULL;
 
diff --git a/src/version.c b/src/version.c
index f8777dc..ae51d72 100644
--- a/src/version.c
+++ b/src/version.c
@@ -779,6 +779,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1561,
+/**/
     1560,
 /**/
     1559,