fix "course attacks that start at 0 never turn off"

stepmania/src/GameState.cpp

@@ -340,10 +340,15 @@ void GameState::Update( float fDelta )
 		for( unsigned s=0; s<m_ActiveAttacks[p].size(); s++ )
 		{
 			Attack &attack = m_ActiveAttacks[p][s];
+			
+			// -1 is the "starts now" sentinel value.  You must add the attack
+			// by calling GameState::LaunchAttack, or else the -1 won't be 
+			// converted into the current music time.  
+			ASSERT( attack.fStartSecond != -1 );
+
 			const bool bCurrentlyEnabled =
-				attack.fStartSecond == -1 ||
-				(attack.fStartSecond < this->m_fMusicSeconds &&
-				 m_fMusicSeconds < attack.fStartSecond+attack.fSecsRemaining);
+				attack.fStartSecond < this->m_fMusicSeconds &&
+				m_fMusicSeconds < attack.fStartSecond+attack.fSecsRemaining;
 
 			if( m_ActiveAttacks[p][s].bOn == bCurrentlyEnabled )
 				continue; /* OK */

stepmania/src/ScreenGameplay.cpp

@@ -787,16 +787,15 @@ void ScreenGameplay::SetupSong( int p, int iSongIndex )
 	GAMESTATE->m_ModsToApply[p].clear();
 	for( unsigned i=0; i<m_asModifiersQueue[p][iSongIndex].size(); ++i )
 	{
-		GAMESTATE->LaunchAttack( (PlayerNumber)p, m_asModifiersQueue[p][iSongIndex][i] );
-		GAMESTATE->m_SongOptions.FromString( m_asModifiersQueue[p][iSongIndex][i].sModifier );
+		/* Hack: Course modifiers that are set to start immediately shouldn't tween on. */
+		Attack a = m_asModifiersQueue[p][iSongIndex][i];
+		if( a.fStartSecond == 0 )
+			a.fStartSecond = -1;	// now
+		
+		GAMESTATE->LaunchAttack( (PlayerNumber)p, a );
+		GAMESTATE->m_SongOptions.FromString( a.sModifier );
 	}
 
-	/* Hack: Course modifiers that are set to start immediately shouldn't tween on. */
-	for( unsigned s=0; s<GAMESTATE->m_ActiveAttacks[p].size(); s++ )
-	{
-		if( GAMESTATE->m_ActiveAttacks[p][s].fStartSecond == 0 )
-			GAMESTATE->m_ActiveAttacks[p][s].fStartSecond = -1;
-	}
 	/* Update attack bOn flags. */
 	GAMESTATE->Update(0);
 	GAMESTATE->RebuildPlayerOptionsFromActiveAttacks( (PlayerNumber)p );