From 0c95f7c234c108e050031fc2504effa90869d04d Mon Sep 17 00:00:00 2001
From: David Sansome <davidsansome@gmail.com>
Date: Sun, 26 Sep 2010 20:59:41 +0000
Subject: [PATCH] Safeguard against a null pipeline in GstEngine::Play.

---
 src/engines/enginebase.cpp | 6 ++++++
 src/engines/enginebase.h   | 2 +-
 src/engines/gstengine.cpp  | 3 +++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/engines/enginebase.cpp b/src/engines/enginebase.cpp
index 2e0576e79..e0246826b 100644
--- a/src/engines/enginebase.cpp
+++ b/src/engines/enginebase.cpp
@@ -78,3 +78,9 @@ void Engine::Base::EmitAboutToEnd() {
 int Engine::Base::AddBackgroundStream(const QUrl& url) {
   return -1;
 }
+
+bool Engine::Base::Play(const QUrl& u, TrackChangeType c) {
+  if (!Load(u, c))
+    return false;
+  return Play();
+}
diff --git a/src/engines/enginebase.h b/src/engines/enginebase.h
index a4a2d8f2a..13553e0f9 100644
--- a/src/engines/enginebase.h
+++ b/src/engines/enginebase.h
@@ -61,7 +61,7 @@ class Base : public QObject, boost::noncopyable {
 
   // Helpers
   virtual bool Load(const QUrl &url, TrackChangeType change);
-  bool Play(const QUrl &u, TrackChangeType c) { return Load(u, c) && Play(); }
+  bool Play(const QUrl &u, TrackChangeType c);
   void SetVolume( uint value );
 
 
diff --git a/src/engines/gstengine.cpp b/src/engines/gstengine.cpp
index 37cac26ec..0c3ef8247 100644
--- a/src/engines/gstengine.cpp
+++ b/src/engines/gstengine.cpp
@@ -496,6 +496,9 @@ void GstEngine::StartFadeout() {
 bool GstEngine::Play( uint offset ) {
   EnsureInitialised();
 
+  if (!current_pipeline_)
+    return false;
+
   QFuture<GstStateChangeReturn> future = current_pipeline_->SetState(GST_STATE_PLAYING);
   BoundFutureWatcher<GstStateChangeReturn, uint>* watcher =
       new BoundFutureWatcher<GstStateChangeReturn, uint>(offset, this);