diff -r 1f2a734581f8 -r 1aa7eba26af5 lemon/bits/path_dump.h
--- a/lemon/bits/path_dump.h	Sun Apr 11 22:28:42 2010 +0200
+++ b/lemon/bits/path_dump.h	Mon Apr 12 13:59:41 2010 +0200
@@ -120,7 +120,7 @@
     }
 
     bool empty() const {
-      return source != target;
+      return predMatrixMap(source, target) == INVALID;
     }
 
     class RevArcIt {