There is some code in the wild (like in gnome-session) that does this
from its custom _constructor() implementation:
{
GObject *obj;
obj = ((chain up));
if (!object_is_viable (obj))
{
g_object_unref (obj);
return NULL;
}
else
return obj;
}
This has never been a valid use of GObject and this code has always
caused memory to be leaked[1] by growing the construction_objects list.
The ability to legitimately return NULL from a constructor was exactly
the reason that we created GInitable, in fact.
That doesn't change the fact that the g_object_new() rewrite will crash
in this case, so instead of doing that, let's emit a critical and avoid
the crash. This will allow people to upgrade their GLib without also
upgrading their gnome-session. Meanwhile, people can fix their broken
code.
[1] not in the strictest sense of the word, because it's still reachable
7d61da0c07