playlist: move checks out of playlist_sync_with_queue()

src/playlist.c

@@ -93,13 +93,14 @@ playlist_queue_song_order(struct playlist *playlist, unsigned order)
 }
 
 /**
- * Check if the player thread has already started playing the "queued"
- * song.
+ * Called if the player thread has started playing the "queued" song.
  */
 static void
-playlist_sync_with_queue(struct playlist *playlist)
+playlist_song_started(struct playlist *playlist)
 {
-	if (pc.next_song == NULL && playlist->queued != -1) {
+	assert(pc.next_song == NULL);
+	assert(playlist->queued >= -1);
+
 	/* queued song has started: copy queued to current,
 	   and notify the clients */
 
@@ -119,7 +120,6 @@ playlist_sync_with_queue(struct playlist *playlist)
 		playlist_delete(playlist, queue_order_to_position(&playlist->queue, current));
 
 	idle_add(IDLE_PLAYER);
-	}
 }
 
 const struct song *
@@ -228,7 +228,8 @@ playlist_sync(struct playlist *playlist)
 	else {
 		/* check if the player thread has already started
 		   playing the queued song */
-		playlist_sync_with_queue(playlist);
+		if (pc.next_song == NULL && playlist->queued != -1)
+			playlist_song_started(playlist);
 
 		/* make sure the queued song is always set (if
 		   possible) */