Bug 845874 added a use of pixman_region32_clear, which, according to http://upstream-tracker.org was added in 0.25.2. Configure checks pixman is >= 0.19.2. This may or may not be fine, depending what systems we consider the GTK3 builds should aim to support support. Pixman 0.26.0, the first stable release after 0.25.2, was released in may 2012.

Initial data point: the first Debian release with gtk3, Wheezy, has pixman 0.26.

We could always do something like this to avoid the dependency

Other data points, from scraping FTPs and release notes: - The first Fedora with Gtk+3 looks like it was Fedora 16 (nov 2011), and it had pixman 0.22. Fedora 17 (may 2012) had pixman 0.24. Fedora 18 (jan 2013) came with pixman 0.26. - The first Redhat release with Gtk+3 is RHEL7, which just came out. I didn't look up what version of pixman it has, but if it has something older than 0.26, then Redhat has serious problems in how they work. - The first OpenSuSE release with Gtk+3 I found was 11.4 (nov 2012) and it had pixman 0.20. But I guess older 11.x releases had something similar. 12.1 (may 2013) had pixman 0.22, 12.2 (jan 2014) had 0.24, 12.3 (sep 2014) will have 0.28. Looks like suse is the drag.

Dates for openSuse are off, they are: 11.4 -> mar 2011 12.1 -> nov 2011 12.2 -> jul 2012 12.3 -> mar 2013

Ah, the previous times I was giving for opensuse are their EOL.

RHEL7/Centos7 have 0.32.

Well, the test slaves don't have a recent enough pixman, that more or less settles it: https://tbpl.mozilla.org/php/getParsedLog.php?id=41976124&tree=Try

Comment on attachment 8442129 [details] [diff] [review] Avoid using region_clear() Review of attachment 8442129 [details] [diff] [review]: ----------------------------------------------------------------- ::: gfx/src/nsRegion.h @@ +42,5 @@ > > class nsRegion > { > + static inline void > + clear_region_workaround(pixman_region32_t *region) Could call that pixman_region32_clear and make the function itself #ifdef MOZ_TREE_PIXMAN.

(In reply to Mike Hommey [:glandium] from comment #7) > Well, the test slaves don't have a recent enough pixman, that more or less > settles it: > https://tbpl.mozilla.org/php/getParsedLog.php?id=41976124&tree=Try Ubuntu 12.04 LTS is what we have on those machines, and that comes with 0.24, although precise-updates has 0.30. 13.04 has 0.28.

I'm sceptical about the quality of early GTK+3 libraries, so the main reason for the workaround would be to build on our (old) build machines. _fini and _init should work fine, yes.

(In reply to Mike Hommey [:glandium] from comment #8) > Comment on attachment 8442129 [details] [diff] [review] > Avoid using region_clear() > > Review of attachment 8442129 [details] [diff] [review]: > ----------------------------------------------------------------- > > ::: gfx/src/nsRegion.h > @@ +42,5 @@ > > > > class nsRegion > > { > > + static inline void > > + clear_region_workaround(pixman_region32_t *region) > > Could call that pixman_region32_clear and make the function itself #ifdef > MOZ_TREE_PIXMAN. Wouldn't that break if you were building against a recent pixman?

(In reply to Jeff Muizelaar [:jrmuizel] from comment #11) > Wouldn't that break if you were building against a recent pixman? That function would be a static member of nsRegion, it wouldn't conflict with pixman's definition.

Comment on attachment 8442494 [details] [diff] [review] Allow binary compatibility with libpixman versions between 0.19.2 and 0.25.2 when building against system libpixman Review of attachment 8442494 [details] [diff] [review]: ----------------------------------------------------------------- ::: gfx/src/nsRegion.h @@ +261,5 @@ > nsCString ToString() const; > private: > pixman_region32_t mImpl; > > +#ifndef MOZ_TREE_PIXMAN Add a comment like: // This is needed for versions of pixman older than 0.25.2