# HG changeset patch
# User Alpar Juttner <alpar@cs.elte.hu>
# Date 1255357582 -3600
# Node ID 4ffd9b129fa804c2c40d10eda3ba733a695b1f99
# Parent  1c247d3e4bbdee4f65a27286f757aab23fbe2d07# Parent  41bdb4d6c8c32c29a1eaebc3eef9bef7ef1f9862
Merge bugfix in #250

diff -r 1c247d3e4bbd -r 4ffd9b129fa8 lemon/path.h
--- a/lemon/path.h	Tue May 05 07:43:28 2009 +0100
+++ b/lemon/path.h	Mon Oct 12 15:26:22 2009 +0100
@@ -1015,18 +1015,20 @@
 
   /// \brief The source of a path
   ///
-  /// This function returns the source of the given path.
+  /// This function returns the source node of the given path.
+  /// If the path is empty, then it returns \c INVALID.
   template <typename Digraph, typename Path>
   typename Digraph::Node pathSource(const Digraph& digraph, const Path& path) {
-    return digraph.source(path.front());
+    return path.empty() ? INVALID : digraph.source(path.front());
   }
 
   /// \brief The target of a path
   ///
-  /// This function returns the target of the given path.
+  /// This function returns the target node of the given path.
+  /// If the path is empty, then it returns \c INVALID.
   template <typename Digraph, typename Path>
   typename Digraph::Node pathTarget(const Digraph& digraph, const Path& path) {
-    return digraph.target(path.back());
+    return path.empty() ? INVALID : digraph.target(path.back());
   }
 
   /// \brief Class which helps to iterate through the nodes of a path