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.

src/regexp_nfa.c

@@ -4435,11 +4435,10 @@ nfa_regmatch(start, submatch, m, endp)
 		{
 		    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)
 		    {

src/testdir/test64.in

@@ -361,6 +361,7 @@ STARTTEST
 :call add(tl, [2, '\(\i\+\) \1', ' abc abc', 'abc abc', 'abc'])
 :call add(tl, [2, '\(\i\+\) \1', 'xgoo goox', 'goo goo', 'goo'])
 :call add(tl, [2, '\(a\)\(b\)\(c\)\(dd\)\(e\)\(f\)\(g\)\(h\)\(i\)\1\2\3\4\5\6\7\8\9', 'xabcddefghiabcddefghix', 'abcddefghiabcddefghi', 'a', 'b', 'c', 'dd', 'e', 'f', 'g', 'h', 'i'])
+:call add(tl, [2, '\(\d*\)a \1b', ' a b ', 'a b', ''])
 :"
 :"""" Look-behind with limit
 :call add(tl, [2, '<\@<=span.', 'xxspanxx<spanyyy', 'spany'])

src/testdir/test64.ok

@@ -815,6 +815,9 @@ OK 2 - \(\i\+\) \1
 OK 0 - \(a\)\(b\)\(c\)\(dd\)\(e\)\(f\)\(g\)\(h\)\(i\)\1\2\3\4\5\6\7\8\9
 OK 1 - \(a\)\(b\)\(c\)\(dd\)\(e\)\(f\)\(g\)\(h\)\(i\)\1\2\3\4\5\6\7\8\9
 OK 2 - \(a\)\(b\)\(c\)\(dd\)\(e\)\(f\)\(g\)\(h\)\(i\)\1\2\3\4\5\6\7\8\9
+OK 0 - \(\d*\)a \1b
+OK 1 - \(\d*\)a \1b
+OK 2 - \(\d*\)a \1b
 OK 0 - <\@<=span.
 OK 1 - <\@<=span.
 OK 2 - <\@<=span.

src/version.c

@@ -728,6 +728,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1093,
 /**/
     1092,
 /**/