From 30c14e235f19442753e5eeeb8a86cbc22960afb1 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 10 Apr 2014 22:02:39 +0300
Subject: [PATCH] Make sure TrackOffsetIters make sense

Disallow creation of iterators that have a path not connected to the
entry endpoint, or an out of range offset.
---
 source/libr2c2/trackoffsetiter.cpp | 33 ++++++++++++++++++++++++++----
 source/libr2c2/trackoffsetiter.h   |  4 ++++
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/source/libr2c2/trackoffsetiter.cpp b/source/libr2c2/trackoffsetiter.cpp
index f8e8a2d..9676985 100644
--- a/source/libr2c2/trackoffsetiter.cpp
+++ b/source/libr2c2/trackoffsetiter.cpp
@@ -24,25 +24,50 @@ TrackOffsetIter::TrackOffsetIter(Track *t, unsigned e, float o):
 	_track(t, e),
 	_offset(_track ? o : 0),
 	_path((_track && _offset) ? _track->get_active_path() : -1)
-{ }
+{
+	validate();
+}
 
 TrackOffsetIter::TrackOffsetIter(Track *t, unsigned e, unsigned p, float o):
 	_track(t, e),
 	_offset(o),
 	_path(p)
-{ }
+{
+	validate();
+}
 
 TrackOffsetIter::TrackOffsetIter(const TrackIter &t, float o):
 	_track(t),
 	_offset(_track ? o : 0),
 	_path((_track && _offset) ? _track->get_active_path() : -1)
-{ }
+{
+	validate();
+}
 
 TrackOffsetIter::TrackOffsetIter(const TrackIter &t, unsigned p, float o):
 	_track(t),
 	_offset(o),
 	_path(p)
-{ }
+{
+	validate();
+}
+
+void TrackOffsetIter::validate()
+{
+	if(!_track)
+		return;
+
+	if(_offset<0)
+		throw invalid_argument("TrackOffsetIter::TrackOffsetIter");
+
+	if(_path>=0)
+	{
+		if(!_track.endpoint().has_path(_path))
+			throw invalid_argument("TrackOffsetIter::TrackOffsetIter");
+		if(_offset>_track->get_type().get_path_length(_path))
+			throw invalid_argument("TrackOffsetIter::TrackOffsetIter");
+	}
+}
 
 BlockIter TrackOffsetIter::block_iter() const
 {
diff --git a/source/libr2c2/trackoffsetiter.h b/source/libr2c2/trackoffsetiter.h
index 776f7a2..3156c08 100644
--- a/source/libr2c2/trackoffsetiter.h
+++ b/source/libr2c2/trackoffsetiter.h
@@ -29,6 +29,10 @@ public:
 	TrackOffsetIter(const TrackIter &, float = 0);
 	TrackOffsetIter(const TrackIter &, unsigned, float);
 
+private:
+	void validate();
+
+public:
 	Track *track() const { return _track.track(); }
 	unsigned entry() const { return _track.entry(); }
 	const TrackIter &track_iter() const { return _track; }
-- 
2.45.2