[Lemon-commits] Alpar Juttner: Merge bugfix in #250

[Lemon HG]

details:   http://lemon.cs.elte.hu/hg/lemon/rev/f5f260a63a9b
changeset: 810:f5f260a63a9b
user:      Alpar Juttner <alpar [at] cs.elte.hu>
date:      Mon Oct 12 15:37:13 2009 +0100
description:
	Merge bugfix in #250

diffstat:

 lemon/path.h |  10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diffs (28 lines):

diff --git a/lemon/path.h b/lemon/path.h
--- a/lemon/path.h
+++ b/lemon/path.h
@@ -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