macosx: work-around a crash when deleting an entire playlist root

(cherry picked from commit 58052ea41383cbd3fa362b24318d529f44797004)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/macosx/playlist.m

@@ -936,6 +936,17 @@
     p_playlist = pl_Get( p_intf );
 
     NSUInteger indexes[i_count];
+    if (i_count == [o_outline_view numberOfRows])
+    {
+#ifndef NDEBUG
+        msg_Dbg( p_intf, "user selected entire list, deleting current playlist root instead of individual items" );
+#endif
+        PL_LOCK;
+        playlist_NodeDelete( p_playlist, [self currentPlaylistRoot], true, false );
+        PL_UNLOCK;
+        [self playlistUpdated];
+        return;
+    }
     [o_selected_indexes getIndexes:indexes maxCount:i_count inIndexRange:nil];
     for (int i = 0; i < i_count; i++)
     {