Re: [gtk-osx-users] Crash on big sur

[John Ralls <jralls ceridwen us>]

> On Jan 26, 2021, at 7:21 AM, Gabriele Greco via gtk-osx-users-list <gtk-osx-users-list gnome org> wrote:
>
> Hi guys,
>
> I found a crash on big sur of my application, that uses gtk-osx through the official build scripts and 
> digging in the net I found the very exact problem in both gimp and inkscape (that are maybe the two biggest 
> gtk 2 programs out there).
>
> The problem itself is in cairo:
>
> https://gitlab.gnome.org/GNOME/gimp/-/issues/5279
>
> ... reading the comments I saw that it has been fixed 1 month ago in the macOS build system of GIMP (that I 
> suppose it's not gtk-osx-build)
>
> because looking at 
>
> https://gitlab.gnome.org/GNOME/gtk-osx
>
> ... that is if I remember correctly the repository where the build system read the modulesets from I do not 
> see the patch, I see only a refcount patch of 5 months ago on cairo:
>
> https://gitlab.gnome.org/GNOME/gtk-osx/-/commit/cea9f2e9e2b65f012ec299f591996507da17533f
>
> It seems that the patch the mono guys did, and that was incorporated in cairo upstream (and the gimp build 
> system, since there is no new cairo version with the patch) is totally different:
>
> https://github.com/mono/bockbuild/pull/162/files
>
> I think there is a fork in gitlab with the correct version that is:
>
> https://gitlab.gnome.org/samm-git/gtk-osx
>
> ... should I switch building from there or do you plan to upstream those patches soon?

The cairo bug report is https://gitlab.freedesktop.org/cairo/cairo/-/issues/420. The mono patch copied by the 
reporter on that issue was not converted to an MR so it was never added to cairo.

The crash has been fixed in Cairo master with https://gitlab.freedesktop.org/cairo/cairo/-/merge_requests/52 
and https://gitlab.freedesktop.org/cairo/cairo/-/merge_requests/102 but is not yet released. The patch in 
Alex's fork is cairo MR52. The much simpler patch in gtk-osx was my first effort from MR52 that the cairo 
devs thought incorrect, see the MR for the gory details. I can replace it with a combined !52 + !102 if 
you've gotten crashes that the simpler patch doesn't fix; I never tested against gtk2 so it won't shock me if 
that's the case.

As for upstreaming Alex's fork, it's incumbent on people maintaining forks to offer merge requests upstream. 
Alex hasn't offered any MRs in a year; Des McGuiness never has.

Regards,
John Ralls