patch 7.4.799

Problem:    Accessing memory before an allocated block.
Solution:   Check for not going before the start of a pattern. (Dominique
            Pelle)

src/fileio.c

@@ -8514,7 +8514,7 @@ do_autocmd_event(event, pat, nested, cmd, forceit, group)
 	 */
 	brace_level = 0;
 	for (endpat = pat; *endpat && (*endpat != ',' || brace_level
-					     || endpat[-1] == '\\'); ++endpat)
+			   || (endpat > pat && endpat[-1] == '\\')); ++endpat)
 	{
 	    if (*endpat == '{')
 		brace_level++;

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    799,
 /**/
     798,
 /**/