updated for version 7.4.100
Problem:    NFA regexp doesn't handle backreference correctly. (Ryuichi
            Hayashida, Urtica Dioica)
Solution:   Always add NFA_SKIP, also when it already exists at the start
            position.
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 0c6ff0b..cf7694b 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -4278,7 +4278,7 @@
 	     * endless loop for "\(\)*" */
 
 	default:
-	    if (state->lastlist[nfa_ll_index] == l->id)
+	    if (state->lastlist[nfa_ll_index] == l->id && state->c != NFA_SKIP)
 	    {
 		/* This state is already in the list, don't add it again,
 		 * unless it is an MOPEN that is used for a backreference or