Comment 23 for bug 1203888

Ok, got it working.

It turns out that there are some more GTK3 tests in the same file which modify the argument list for the item_inserted_cb. It is necessary to remove all the tests so that only the GTK3 versions are present regardless of whether we are actually using GTK3 or not. Failure to do this caused the callback to be called with the wrong args, causing the segfault.

What I still don't understand:

* Why "insert" was special cased, but "remove" was not.
* How did this code ever work before.
* What changed to make it stop working.