Like gtk_window_set_default_size(), but @width and @height are interpreted in terms of the base size and increment set with gtk_window_set_geometry_hints.
width in resize increments, or -1 to unset the default width
height in resize increments, or -1 to unset the default height
Deprecated: This function does nothing. If you want to set a default size, use gtk_window_set_default_size() instead.
3.0
See Implementation
Like gtk_window_set_default_size(), but @width and @height are interpreted in terms of the base size and increment set with gtk_window_set_geometry_hints.