fix [22632]: check psz_arturl before using it

src/input/meta.c

@@ -165,7 +165,7 @@ int input_ArtFind( playlist_t *p_playlist, input_item_t *p_item )
     input_FindArtInCache( p_playlist, p_item );
 
     char *psz_arturl = input_item_GetArtURL( p_item );
-    if( !strncmp( psz_arturl, "file://", strlen( "file://" ) ) )
+    if( psz_arturl && !strncmp( psz_arturl, "file://", strlen( "file://" ) ) )
     {
         free( psz_arturl );
         return 0; /* Art is in cache, no need to go further */

src/playlist/engine.c

@@ -534,6 +534,7 @@ void playlist_PreparseLoop( playlist_preparse_t *p_obj )
             }
             /* We already have all needed meta, but we need art right now */
             else if( p_playlist->p_fetcher->i_art_policy == ALBUM_ART_ALL &&
+                     !psz_arturl ? 1 :
                         strncmp( psz_arturl, "file://", strlen("file://") ) )
             {
                 preparse_item_t p;