API compatibility question

[Alexander Larsson <alexl redhat com>]

I have a question about what type of API compatibility we provide.

I've converted GnomeIconTheme to just be a wrapper of GtkIconTheme,
which works fine, and is 100% API and ABI compatible. However, since
GnomeIconTheme is deprecated, i'd like to make gnome_icon_lookup, that
takes a GnomeIconTheme take a GtkIconTheme instead. To secure ABI
backwards compatibility the new gnome_icon_lookup looks at
GNOME_IS_ICON_THEME (icon_theme), and automatically gets the wrapped
GtkIconTheme if you pass in a GnomeIconTheme.

However, this is a slight API incompatibility, in that any user of the
old API will pass a GnomeIconTheme instead of a GtkIconTheme which will
cause a compiler warning (but work fine).

So, the question is, is it ok to add this warning to 3rd party code, or
do I have to make the icon_theme function argument of type gpointer,
which would fix the warning, but look pretty ugly.

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 Alexander Larsson                                            Red Hat, Inc 
                   alexl redhat com    alla lysator liu se 
He's a leather-clad amnesiac vagrant with a winning smile and a way with the 
ladies. She's a high-kicking cat-loving single mother looking for love in all 
the wrong places. They fight crime!