Comment 3 for bug 1847129

Then theme is NULL there...

Can you check if update_metacity_theme_cb is called in gtk-window-decorator.c? Add debug info for theme type and theme name. Also check if that function is called before gwd_theme_update_titlebar_font.

Looking at code I found some problems...
1) `GObject parent;` should be `GWDTheme parent;` in _GWDThemeMetacity and _GWDThemeCairo.
2) `g_set_object (&gwd_theme, gwd_theme_new (type, settings));` will cause memory leak. g_set_object is documented to increment the reference count of new object. Should be changed to something like this:
GWDTheme *theme;

theme = gwd_theme_new (type, settings);
g_set_object (&gwd_theme, theme);
g_object_unref (theme);