updated for version 7.4.253
Problem:    Crash when using cpp syntax file with pattern using external
            match. (Havard Garnes)
Solution:   Discard match when end column is before start column.
diff --git a/src/regexp.c b/src/regexp.c
index 0a590f6..2c364b3 100644
--- a/src/regexp.c
+++ b/src/regexp.c
@@ -4146,7 +4146,8 @@
 	    {
 		/* Only accept single line matches. */
 		if (reg_startzpos[i].lnum >= 0
-			&& reg_endzpos[i].lnum == reg_startzpos[i].lnum)
+			&& reg_endzpos[i].lnum == reg_startzpos[i].lnum
+			&& reg_endzpos[i].col >= reg_startzpos[i].col)
 		    re_extmatch_out->matches[i] =
 			vim_strnsave(reg_getline(reg_startzpos[i].lnum)
 						       + reg_startzpos[i].col,