fix OnCommand sometimes run twice

stepmania/src/Transition.cpp

@@ -63,6 +63,17 @@ bool Transition::EarlyAbortDraw() const
 	return m_State == waiting;
 }
 
+/* Our parent might send us OnCommand.  We do that ourself, because
+ * we sometimes want to know GetLengthSeconds before StartTransitioning.
+ * Make sure we don't process OnCommand twice. */
+void Transition::PlayCommand( const CString &sCommandName, Actor *pParent )
+{
+	if( sCommandName == "On" )
+		return;
+
+	ActorFrame::PlayCommand( sCommandName, pParent );
+}
+
 void Transition::StartTransitioning( ScreenMessage send_when_done )
 {
 	if( m_State != waiting )

stepmania/src/Transition.h

@@ -16,6 +16,7 @@ public:
 	void Load( CString sBGAniDir );
 
 	virtual void UpdateInternal( float fDeltaTime );
+	virtual void PlayCommand( const CString &sCommandName, Actor *pParent = NULL );
 
 	virtual void StartTransitioning( ScreenMessage send_when_done = SM_None );
 	virtual bool EarlyAbortDraw() const;