Handle randomization of broken songs correctly

The old code didn't update the song in the timeline, which lead to some
interesting issues.

src/org/kreed/vanilla/Song.java

@@ -171,6 +171,27 @@ public class Song implements Parcelable {
 		albumId = cursor.getLong(5);
 	}
 
+	/**
+	 * Copies the fields from the given Song to this Song.
+	 *
+	 * @param other The Song to copy from.
+	 */
+	public void copy(Song other)
+	{
+		if (other == null) {
+			id = -1;
+			return;
+		}
+
+		id = other.id;
+		albumId = other.albumId;
+		path = other.path;
+		title = other.title;
+		album = other.album;
+		artist = other.artist;
+		flags = other.flags;
+	}
+
 	/**
 	 * Query the MediaStore, if necessary, to fill this Song's fields.
 	 *

src/org/kreed/vanilla/SongTimeline.java

@@ -329,7 +329,7 @@ public final class SongTimeline {
 		}
 
 		if (song == null || !song.query(false)) {
-			song = Song.randomSong();
+			song.copy(Song.randomSong());
 			if (song == null || !song.query(false))
 				return null;
 		}