Changing external screen resolution with dual monitors

[Guy Stone]

[Impact]

Due to a bug in GTK+2, mate-display-properties crashes when the screen resolution is changed *outside* of it (e.g. by changing the resolution not via that app, but somewhere else).

The attached patches fix the issue in GTK+2 and prevent crashing of m-d-p.

Since this issue caused much inconvenience for users, the fix should be backported to all current stable releases of Ubuntu.

[Test Case]

The easiest way to reproduce it is via Virtualbox:

1. Run mate-display-properties in the VM.
2. Make the VM go full-screen.
3. See m-d-p crash.

[Regression Potential]

After several months of testing the patched version of GTK+2 in Debian Jessie, I found no regressions.
I consider the regression risk very low here.

There were originally some bugs with a few applications (notably Spotify) crashing. We think we've backported patches to fix that - some refcounting issues - but please check a few apps to see they still work.

[ Original report ]

Changing extrnal screen resolution with dual mon

ProblemType: Crash
DistroRelease: Ubuntu 14.10
Package: mate-control-center 1.8.1+dfsg1-4
ProcVersionSignature: Ubuntu 3.16.0-6.11-generic 3.16.0-rc7
Uname: Linux 3.16.0-6-generic i686
ApportVersion: 2.14.5-0ubuntu3
Architecture: i386
CrashCounter: 1
Date: Sun Aug 3 07:09:21 2014
ExecutablePath: /usr/bin/mate-display-properties
InstallationDate: Installed on 2014-08-03 (0 days ago)
InstallationMedia: Ubuntu MATE 14.10 "Utopic Unicorn" - Alpha i386 (20140731)
ProcCmdline: mate-display-properties
SegvAnalysis: Skipped: missing required field "Disassembly"
Signal: 11
SourcePackage: mate-control-center
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

StacktraceTop:
 ?? ()
 gdk_event_apply_filters (filters=<optimized out>, event=0x90aa720, xevent=0xbfb1f34c) at /build/buildd/gtk+2.0-2.24.24/gdk/x11/gdkevents-x11.c:356
 gdk_event_translate (display=display@entry=0x8f040a0, event=event@entry=0x90aa720, xevent=xevent@entry=0xbfb1f34c, return_exposes=return_exposes@entry=0) at /build/buildd/gtk+2.0-2.24.24/gdk/x11/gdkevents-x11.c:1052
 _gdk_events_queue (display=display@entry=0x8f040a0) at /build/buildd/gtk+2.0-2.24.24/gdk/x11/gdkevents-x11.c:2336
 gdk_event_dispatch (source=source@entry=0x8f0a1c8, callback=0x0, user_data=0x0) at /build/buildd/gtk+2.0-2.24.24/gdk/x11/gdkevents-x11.c:2397

[Martin Wimpress (flexiondotorg)]

Added to the upstream issue tracker.

  * https://github.com/mate-desktop/mate-control-center/issues/48

[Vlad Orlov (monsta)]

I suspect this is a bug in GTK+2, which is still not fixed upstream.
They've fixed it in GTK+3 only, that's why in MATE GTK+3 mate-display-properties doesn't crash.

I've linked the upstream bug report here.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Vlad Orlov (monsta)]

Attached the patch for GTK+2 which makes gdk_event_apply_filters function safe against changes in filter list. This patch is cherry-picked from GTK+3 and adapted to GTK+2.

I've tested it in Precise, Trusty and Utopic. It applies cleanly in all three Ubuntu releases, and mate-display-properties doesn't crash anymore after GTK+2 is patched.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "This patch makes gdk_event_apply_filters function safe against changes in filter list." seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Martin Wimpress (flexiondotorg)]

This issue was fixed by the following upstream commit.

  * https://git.gnome.org/browse/gtk+/commit/?h=gtk-2-24&id=ee95f3d7259c0859ce41189b781b4339b4cd64aa

GTK 2.24.26 has since been released and incorporates the fix.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gtk+2.0 - 2.24.26-0ubuntu1

---------------
gtk+2.0 (2.24.26-0ubuntu1) vivid; urgency=medium

  * New upstream release.
    + Protect gdk_event_apply_filters_safe from changes in the filter list
    (LP: #1351890)
  * Now need to build with --enable-man to build the manpages, and build-dep
    on libxml2-utils to get xmlcatalog which configure uses to decide whether
    to build them.
 -- Iain Lane <email address hidden> Fri, 20 Feb 2015 17:48:37 +0000

[Vlad Orlov (monsta)]

Thanks.
Please apply the patch in Precise, Trusty and Utopic.

[Sebastien Bacher (seb128)]

That commit creates issues, for example the spotify linux client segfaults with it, see https://bugzilla.gnome.org/show_bug.cgi?id=745536

[Iain Lane (laney)]

I'm going to backport those extra commits now. If you want the SRU, please update those diffs too.

[Vlad Orlov (monsta)]

Update what?
The debdiffs are fine.

[Vlad Orlov (monsta)]

Sebastien, the new segfault seems to be fixed upstream in https://git.gnome.org/browse/gtk+/commit/?h=gtk-2-24&id=5efefdb6550b3f00d5ca159c2ff74326bfd0e94b

[Vlad Orlov (monsta)]

Iain, did you mean I need to include the new fix in the debdiffs as well?

[Vlad Orlov (monsta)]

Whoops, looks like there are two fixes actually, the second one is in https://git.gnome.org/browse/gtk%2B/commit/?id=22eb70adab72a5c14f063ea15f8195087ff1dcd8

[Vlad Orlov (monsta)]

Iain, I've seen you've added them in Debian Jessie and Ubuntu 15.04, thanks :)

[Vlad Orlov (monsta)]

[Impact]

Due to a bug in GTK+2, mate-display-properties crashes when the screen resolution is changed *outside* of it (e.g. by changing the resolution not via that app, but somewhere else).

The attached patches fix the issue in GTK+2 and prevent crashing of m-d-p.

Since this issue caused much inconvenience for users, the fix should be backported to all current stable releases of Ubuntu.

[Test Case]

The easiest way to reproduce it is via Virtualbox:

1. Run mate-display-properties in the VM.
2. Make the VM go full-screen.
3. See m-d-p crash.

[Regression Potential]

After several months of testing the patched version of GTK+2 in Debian Jessie, I found no regressions.
I consider the regression risk very low here.

[Vlad Orlov (monsta)]

There we go. All three debdiffs have been updated to include two more patches mentioned in the comments above (thanks to Sebastien Bacher and Iain Lane).

[Vlad Orlov (monsta)]

Hmm, not sure why Ubuntu Sponsors Team wasn't auto-subscribed after my debdiffs. Ok, fixed that manually.

[Vlad Orlov (monsta)]

Any progress on reviewing the debdiffs?

[Iain Lane (laney)]

sorry, I forgot to subscribe so I wasn't getting emails from this bug. Seb just pointed me to it again.

I'm going to look at your diffs now.

[Iain Lane (laney)]

uploaded, thanks!

[Brian Murray (brian-murray)]

Hello Guy, or anyone else affected,

Accepted gtk+2.0 into precise-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/gtk+2.0/2.24.10-0ubuntu6.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Vlad Orlov (monsta)]

Looks good in Precise, waiting for Trusty package so I could tag it as verification-done.

[Sebastien Bacher (seb128)]

the trusty SRU is waiting for review from the SRU team
https://launchpad.net/ubuntu/trusty/+queue?queue_state=1&queue_text=gtk

[xiaoyiwu (xiaoyiwu)]

this bug is exist in gtk+2.0-2.24.25

[xiaoyiwu (xiaoyiwu)]

(gdb) bt
#0 0x00000000007c8030 in ?? ()
#1 0x00007ffff652c073 in gdk_event_apply_filters (filters=0x8dcf80,
    event=<optimized out>, xevent=<optimized out>)
    at /build/buildd/gtk+2.0-2.24.25/gdk/x11/gdkevents-x11.c:356
#2 gdk_event_translate (display=0x669020, event=0x8c9c80,
    xevent=0x7fffffffdc20, return_exposes=9324560, return_exposes@entry=0)
    at /build/buildd/gtk+2.0-2.24.25/gdk/x11/gdkevents-x11.c:1052
#3 0x00007ffff652d696 in _gdk_events_queue (display=display@entry=0x669020)
    at /build/buildd/gtk+2.0-2.24.25/gdk/x11/gdkevents-x11.c:2336
#4 0x00007ffff652d73e in gdk_event_dispatch (source=<optimized out>,
    callback=<optimized out>, user_data=<optimized out>)
    at /build/buildd/gtk+2.0-2.24.25/gdk/x11/gdkevents-x11.c:2397
#5 0x00007ffff507ec5d in g_main_context_dispatch ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#6 0x00007ffff507ef48 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#7 0x00007ffff507f272 in g_main_loop_run ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#8 0x00007ffff68b8747 in IA__gtk_main ()
    at /build/buildd/gtk+2.0-2.24.25/gtk/gtkmain.c:1271

[Vlad Orlov (monsta)]

The fix for Trusty is still in that queue - did something wrong happened?

[xiaoyiwu (xiaoyiwu)]

add a monitor in utopic!

[Vlad Orlov (monsta)]

Won't happen, Utopic is EOL since 23 July 2015

https://lists.ubuntu.com/archives/ubuntu-announce/2015-July/000197.html

[Vlad Orlov (monsta)]

Guys, please do something for Trusty...

[Timo Aaltonen (tjaalton)]

Hello Guy, or anyone else affected,

Accepted gtk+2.0 into trusty-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/gtk+2.0/2.24.23-0ubuntu1.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Vlad Orlov (monsta)]

Looks good in Trusty. Since Precise has the fix in -proposed already as well, tagging it as verification-done.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gtk+2.0 - 2.24.10-0ubuntu6.2

---------------
gtk+2.0 (2.24.10-0ubuntu6.2) precise; urgency=low

  * fix_gdk_event_apply_filters.patch: new patch. Makes gdk_event_apply_filters
    function safe against changes in the filter list, prevents weird crashes in
    various apps. (LP: #1351890)
  * gdk-Fix-GdkWindowFilter-internal-refcounting.patch,
    gdkwindow-Fix-event-unref-iteration.patch: new patches. Fix refcounting
    errors after fix_gdk_event_apply_filters.patch, prevent crashes in some
    applications like Spotify.

 -- Vlad Orlov <email address hidden> Tue, 28 Jul 2015 10:11:37 +0100

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for gtk+2.0 has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gtk+2.0 - 2.24.23-0ubuntu1.3

---------------
gtk+2.0 (2.24.23-0ubuntu1.3) trusty; urgency=medium

  * fix_gdk_event_apply_filters.patch: new patch. Makes gdk_event_apply_filters
    function safe against changes in the filter list, prevents weird crashes in
    various apps. (LP: #1351890)
  * gdk-Fix-GdkWindowFilter-internal-refcounting.patch,
    gdkwindow-Fix-event-unref-iteration.patch: new patches. Fix refcounting
    errors after fix_gdk_event_apply_filters.patch, prevent crashes in some
    applications like Spotify.

 -- Vlad Orlov <email address hidden> Tue, 28 Jul 2015 10:17:14 +0100

[Vlad Orlov (monsta)]

Thanks! :)