Fix a Player 2 assist tick / clap bug.

Docs/Changelog_sm5.txt

@@ -12,6 +12,10 @@ StepMania 5.0 Preview 2 | 20110???
 ----------
 * [PlayerOptions] Removed the ScoreDisplay mod choices. Use lua to make your
   own scoring formulas that work in reverse instead. [Wolfman2000]
+* [ScreenGameplay] Fix an assist tick bug if there was no Player 1. Note that
+  this changes the behavior slightly: it is the first enabled player, or
+  master player, that gets the ticks now. A better solution will be looked at
+  in the future. [Wolfman2000]
 
 2011/06/04
 ----------

src/GameState.h

@@ -139,6 +139,14 @@ public:
 	PlayerNumber GetFirstDisabledPlayer() const;
 	bool IsCpuPlayer( PlayerNumber pn ) const;
 	bool AnyPlayersAreCpu() const;
+	
+	/**
+	 * @brief Retrieve the present master player number.
+	 * @return The master player number. */
+	PlayerNumber GetMasterPlayerNumber() const
+	{
+		return m_MasterPlayerNumber;
+	}
 
 	bool IsCourseMode() const;
 	bool IsBattleMode() const; // not Rave

src/ScreenGameplay.cpp

@@ -1393,7 +1393,7 @@ void ScreenGameplay::PlayTicks()
 	/* TODO: Allow all players to have ticks. Not as simple as it looks.
 	 * If a loop takes place, it could make one player's ticks come later
 	 * than intended. Any help here would be appreciated. -Wolfman2000 */
-	Player &player = *m_vPlayerInfo[0].m_pPlayer;
+	Player &player = *m_vPlayerInfo[GAMESTATE->GetMasterPlayerNumber()].m_pPlayer;
 	const NoteData &nd = player.GetNoteData();
 	m_GameplayAssist.PlayTicks( nd, player.GetPlayerState() );
 }