updated for version 7.3.1149
Problem:    New regexp engine: Matching plain text could be faster.
Solution:   Detect a plain text match and handle it specifically.  Add
            vim_regfree().
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index a8b0fb3..3efb381 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -7779,7 +7779,7 @@
 		curwin->w_cursor.col = (colnr_T)(regmatch.startp[0] - p);
 	    else
 		EMSG(_(e_nomatch));
-	    vim_free(regmatch.regprog);
+	    vim_regfree(regmatch.regprog);
 	}
 	/* Move to the NUL, ignore any other arguments. */
 	eap->arg += STRLEN(eap->arg);