message: Fix bug when Shift + Up arrow. Shouldn't deselectAll if we are holding Shift (mac)
diff: @@ -278,8 +278,15 @@ extern void *ctx;
  // Select previous cell
  NSIndexPath *previousIndexPath = [datasource previousIndexPathFrom:indexPath];
  if (previousIndexPath != nil)
  + {
  + // deselect all previous if we don't hold Shift
  + NSUInteger flags = [[NSApp currentEvent] modifierFlags];
  + if (!(flags & NSShiftKeyMask))
  {
  [self deselectAll:self];
  + }
  +
  + // Select previous cell
  [self selectItemsAtIndexPaths:[NSSet setWithCollectionViewIndexPath:previousIndexPath]
  scrollPosition:NSCollectionViewScrollPositionNone];
  