updated for version 7.3.1088
Problem:    New regexp engine: \@<= and \@<! are not implemented.
Solution:   Implement look-behind matching.  Fix off-by-one error in old
            regexp engine.
diff --git a/src/testdir/test64.ok b/src/testdir/test64.ok
index b014a16..31baa4f 100644
--- a/src/testdir/test64.ok
+++ b/src/testdir/test64.ok
@@ -817,16 +817,25 @@
 OK 2 - \(a\)\(b\)\(c\)\(dd\)\(e\)\(f\)\(g\)\(h\)\(i\)\1\2\3\4\5\6\7\8\9
 OK 0 - <\@<=span.
 OK 1 - <\@<=span.
+OK 2 - <\@<=span.
 OK 0 - <\@1<=span.
 OK 1 - <\@1<=span.
+OK 2 - <\@1<=span.
 OK 0 - <\@2<=span.
 OK 1 - <\@2<=span.
+OK 2 - <\@2<=span.
 OK 0 - \(<<\)\@<=span.
 OK 1 - \(<<\)\@<=span.
+OK 2 - \(<<\)\@<=span.
 OK 0 - \(<<\)\@1<=span.
 OK 1 - \(<<\)\@1<=span.
+OK 2 - \(<<\)\@1<=span.
 OK 0 - \(<<\)\@2<=span.
 OK 1 - \(<<\)\@2<=span.
+OK 2 - \(<<\)\@2<=span.
+OK 0 - \(foo\)\@<!bar.
+OK 1 - \(foo\)\@<!bar.
+OK 2 - \(foo\)\@<!bar.
 OK 0 - \_[^8-9]\+
 OK 1 - \_[^8-9]\+
 OK 2 - \_[^8-9]\+
@@ -844,7 +853,7 @@
 <T="7">Ac 7</Title>
 ghi
 
-xxxstart3
+xxstart3
 -0-
 ffo
 bob