updated for version 7.3.1093
Problem:    New regexp engine: When a sub expression is empty \1 skips a
            character.
Solution:   Make \1 try the current position when the match is emtpy.
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 11aca9c..8abdbb5 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -4435,11 +4435,10 @@
 		{
 		    if (bytelen == 0)
 		    {
-			/* empty match always works, add NFA_SKIP with zero to
-			 * be used next */
-			addstate_here(thislist, t->state->out, &t->subs,
+			/* empty match always works, output of NFA_SKIP to be
+			 * used next */
+			addstate_here(thislist, t->state->out->out, &t->subs,
 								    &listidx);
-			thislist->t[listidx + 1].count = 0;
 		    }
 		    else if (bytelen <= clen)
 		    {