From c47f3fad07af11210c9cbd65d87964794189065e Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 20 Dec 2009 00:30:50 +0000
Subject: [PATCH] Consider failed track or block traversal a fatal error

---
 source/libmarklin/block.cpp | 11 ++++-------
 source/libmarklin/block.h   |  2 +-
 source/libmarklin/track.cpp |  4 ++--
 source/libmarklin/track.h   |  2 +-
 4 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/source/libmarklin/block.cpp b/source/libmarklin/block.cpp
index 9a9164e..e9c170c 100644
--- a/source/libmarklin/block.cpp
+++ b/source/libmarklin/block.cpp
@@ -68,7 +68,7 @@ int Block::get_endpoint_by_link(const Block &other) const
 	return -1;
 }
 
-int Block::traverse(unsigned epi, float *len) const
+unsigned Block::traverse(unsigned epi, float *len) const
 {
 	if(epi>=endpoints.size())
 		throw InvalidParameterValue("Endpoint index out of range");
@@ -93,17 +93,14 @@ int Block::traverse(unsigned epi, float *len) const
 		if(len)
 			*len += track->get_type().get_path_length(cur_path);
 
-		int other_ep = track->traverse(track_ep, cur_path);
-		if(other_ep<0)
-			return -1;
-
+		unsigned other_ep = track->traverse(track_ep, cur_path);
 		for(unsigned i=0; i<endpoints.size(); ++i)
 			if(endpoints[i].track==track && endpoints[i].track_ep==static_cast<unsigned>(other_ep))
 				return i;
 
 		Track *next = track->get_link(other_ep);
-		if(tracks.count(next)==0)
-			return -1;
+		if(!tracks.count(next))
+			throw LogicError("Block traversal strayed out of the block");
 		track_ep = next->get_endpoint_by_link(*track);
 		track = next;
 	}
diff --git a/source/libmarklin/block.h b/source/libmarklin/block.h
index 64f02e5..7c0f8ac 100644
--- a/source/libmarklin/block.h
+++ b/source/libmarklin/block.h
@@ -47,7 +47,7 @@ public:
 	const std::set<Track *> &get_tracks() const { return tracks; }
 	const std::vector<Endpoint> &get_endpoints() const { return endpoints; }
 	int get_endpoint_by_link(const Block &) const;
-	int traverse(unsigned, float * =0) const;
+	unsigned traverse(unsigned, float * =0) const;
 	void check_link(Block &);
 	Block *get_link(unsigned) const;
 	bool reserve(const Train *);
diff --git a/source/libmarklin/track.cpp b/source/libmarklin/track.cpp
index 6c72c46..3c2a410 100644
--- a/source/libmarklin/track.cpp
+++ b/source/libmarklin/track.cpp
@@ -223,7 +223,7 @@ Track *Track::get_link(unsigned i) const
 	return links[i];
 }
 
-int Track::traverse(unsigned i, unsigned path) const
+unsigned Track::traverse(unsigned i, unsigned path) const
 {
 	const vector<Endpoint> &eps = type.get_endpoints();
 	if(i>=eps.size())
@@ -246,7 +246,7 @@ int Track::traverse(unsigned i, unsigned path) const
 				return j;
 	}
 
-	return -1;
+	throw Exception("Track endpoint did not have a counterpart");
 }
 
 Point Track::get_point(unsigned epi, unsigned path, float d) const
diff --git a/source/libmarklin/track.h b/source/libmarklin/track.h
index b000e34..21c505f 100644
--- a/source/libmarklin/track.h
+++ b/source/libmarklin/track.h
@@ -71,7 +71,7 @@ public:
 	void break_links();
 	const std::vector<Track *> &get_links() const { return links; }
 	Track *get_link(unsigned) const;
-	int traverse(unsigned, unsigned) const;
+	unsigned traverse(unsigned, unsigned) const;
 	Point get_point(unsigned, unsigned, float) const;
 
 	/**
-- 
2.43.0