Fix crash on delete (Refs:#205)

src/playlist/item-ext.c

@@ -663,6 +663,7 @@ int playlist_Delete( playlist_t * p_playlist, int i_id )
         /* Hack we don't call playlist_Control for lock reasons */
         p_playlist->status.i_status = PLAYLIST_STOPPED;
         p_playlist->request.b_request = VLC_TRUE;
+        p_playlist->request.p_item = NULL;
         msg_Info( p_playlist, "stopping playback" );
         b_flag = VLC_TRUE;
     }

src/playlist/playlist.c

@@ -866,7 +866,7 @@ static playlist_item_t * NextItem( playlist_t *p_playlist )
             i_skip = p_playlist->request.i_skip;
             i_goto = p_playlist->request.i_goto;
 
-            if( p_playlist->i_index == -1 ) p_playlist->i_index = 0;
+            if( p_playlist->i_index < 0 ) p_playlist->i_index = 0;
             p_new = p_playlist->pp_items[p_playlist->i_index];
 
             if( i_goto >= 0  && i_goto < p_playlist->i_size )