Fix memory leaks

[hfiguiere]

Build with address sanitizer and run the tests

[hfiguiere]

I guess that why we skipp the valgrind test?

CI is green now. There are some leaks left though, not sure how to address them.

[TingPing]

I guess that why we skipp the valgrind test?

I think it was too slow, like beyond the limits of Github CI.

[hfiguiere]

yeah I saw after that we have asan without leaksanitizer.

[smcv]

There are some leaks left though, not sure how to address them

#5690 fixed some more (in production code), and #5691 will fix more (in tests); reviews welcome. I think the only way to eliminate memory leaks is to work our way through like that, one test or a few tests at a time, until they all pass, and then add AddressSanitizer to the Github CI so that it won't regress.

[hfiguiere]

Sadly some of the remaining leaks in test haven't been fixed with your PR.

I will file issue for them.

[smcv]

Sadly some of the remaining leaks in test haven't been fixed with your PR

Yeah, it's a slow process - I only got as far as making testlibrary pass (with GLib 2.79.2, other versions might have different leaks).