Created attachment 5497
Update for Upower 0.99
This patch adds a conditional check for a change upower 0.99 requires, obviously things will still work with upower 0.9.23 and before.
After applying this patch to xfce4-settings 4.11.2 (+ UPower 0.99.0) in Mageia Cauldron (latest development version), I see segfault at startup. Other users have also reported similar issues.
xfsettingsd: segfault at 0 ip b6de6bcd sp bffbd2d4 error 4 in libupower-glib.so.2.0.0[b6dd9000+25000]
I'm also seeing messages like this in .xsession-errors:
(xfsettingsd:3380): libupower-glib-WARNING **: Couldn't connect to proxy: Timeout was reached
If it's crashing, can you get a backtrace with debug symbols? Maybe we can track it down that way.
For the warnings you can try launching xfsettingsd with --g-fatal-warnings and it will crash on a warning, a backtrace of that would help us eliminate those runtime warnings too.
Created attachment 5566
Here's the bactrace after attaching gdb to running xfsettingsd process after startup.
Applied patch from bug 11045 comment 1 to see if all this is somehow magically related to forking issue and seems it fixed the segfault.
I'll apply the patch also to Mageia xfce4-settings package and ask feedback from other users.
For what's it worth (not much :), I'll just say it:
This patch is in use at Gentoo's Portage ~arch (~arch equals to something like "testing" or "unstable")
And most Gentoo users use ~ərch, so most Gentoo Xfce users are using this patch, and we haven't received any bug reports about it
So far, all good
Oh awesome! I was just waiting on my Mageia box to finish building to I could update it to Cauldron. I guess I'll hold off in hopes I accidentally fixed it :)
Affected users confirmed in downstream bug report  that after applying the patch from bug 11045 xfsettingsd doesn't segfault anymore with UPower 0.99 patch.
Applied to master.
Author: Eric Koegel <email@example.com>
Date: Wed May 28 07:55:39 2014 +0300
Add support for upower 0.99 (bug #10918)
Amend the signal handler for the changing of display properties to work
with upower 0.99.