player/Control: add method LockApplyBorderPause()

src/player/Control.hxx

@@ -351,6 +351,17 @@ public:
 	 */
 	void LockSetBorderPause(bool border_pause);
 
+	bool ApplyBorderPause() {
+		if (border_pause)
+			state = PlayerState::PAUSE;
+		return border_pause;
+	}
+
+	bool LockApplyBorderPause() {
+		const ScopeLock lock(mutex);
+		return ApplyBorderPause();
+	}
+
 	void Kill();
 
 	gcc_pure

src/player/Thread.cxx

@@ -948,18 +948,11 @@ Player::SongBorder()
 
 	ActivateDecoder();
 
-	pc.Lock();
-
-	const bool border_pause = pc.border_pause;
+	const bool border_pause = pc.LockApplyBorderPause();
 	if (border_pause) {
 		paused = true;
-		pc.state = PlayerState::PAUSE;
-	}
-
-	pc.Unlock();
-
-	if (border_pause)
 		idle_add(IDLE_PLAYER);
+	}
 }
 
 inline void