Mate-appearance-properties: segfault on specific combinations of themes and fonts

[RichardNeill]

The combination of (exactly):

• an Ambience-derived theme:
• the fixed-width font = Terminus
• the 2nd time the Appearance->fonts option is opened

will result in a repeatable segfault.
This is a really weird condition, but it is easy and reliable to reproduce.

mate-appearance-properties: ../../../../src/cairo-scaled-font.c:459: _cairo_scaled_glyph_page_destroy: Assertion `!scaled_font->cache_frozen' failed.
Aborted (core dumped)

I originally filed this report downstream, here, with more details:
https://bugs.launchpad.net/ubuntu/+source/mate-control-center/+bug/1464069

[monsta]

Weird one, I agree. Question: did you try it in Wily only?

I'd try it there later - but only after all MATE packages will be upgraded to 1.10. The current mix of 1.8 and 1.10 is known to cause issues (see the news post here).

[sboddy]

See https://bugs.launchpad.net/ubuntu/+source/terminator/+bug/1294699 for an earlier instance of this same issue, and details of an upstream (cairo) bug report that is getting no attention for now.

[IronWolve]

Same issue, running Mate 1.12 Ambiant Gtk2/gtk3, Ubuntu Medium 10 font, opensuse tumbleweed.

mate-appearance-properties: cairo-scaled-font.c:459: _cairo_scaled_glyph_page_destroy: Assertion `!scaled_font->cache_frozen' failed.
Aborted (core dumped)

[monsta]

Ok, I confirm it in Mint 17.3. Ambiance + Terminus crashes mate-appearance-properties alright.

Here's the (huge) backtrace: http://pastebin.com/NkY0VRRQ

The backtrace confirms that the problem should be addressed in cairo, or maybe in murrine theme engine (see comments at this bug report).

[monsta]

So, this is the same issue as in mate-desktop/mate-panel#328, and it is fixed by patching Murrine theme engine. It's a pity that Murrine isn't maintained upstream for years, so the patch should be applied in the distros. So I've sent the patch (in the form of debdiff) to Debian and Ubuntu, and other people sent the patch to Arch and Fedora.

Debian: https://bugs.debian.org/827134
Ubuntu: https://bugs.launchpad.net/bugs/1294699
Arch: https://bugs.archlinux.org/48294
Fedora: https://bugzilla.redhat.com/1310313

Patch itself (in the attachment): mate-desktop/mate-panel#328 (comment)