Merges the shape masks for any child windows into the
shape mask for window. i.e. the union of all masks
for window and its children will become the new mask
for window. See gdk_window_shape_combine_region().
This function is distinct from gdk_window_set_child_shapes()
because it includes window's shape mask in the set of shapes to
be merged.
Merges the shape masks for any child windows into the shape mask for window. i.e. the union of all masks for window and its children will become the new mask for window. See gdk_window_shape_combine_region(). This function is distinct from gdk_window_set_child_shapes() because it includes window's shape mask in the set of shapes to be merged.