Compiz crashes when iconifying window with applied input mask

[Alex]

This crash happens for me always when I apply input mask to a window and trying to iconify this window (even with alt+space menu)

I've attached a simplified test case which reproduces the issue
To run:
 gcc main.c `pkg-config --cflags --libs gtk+-2.0` -o main && ./main

It uses gdk_window_input_shape_combine_region() to apply input mask, but if you rewrite an app to use gtk_widget_input_shape_combine_mask() or XShapeCombineMask() (with ShapeInput parameter) compiz will crash as well.

Ubuntu 13.04
Compiz 0.9.9.0
What you expected to happen:
    Successful iconification of a window
What happened instead:
    compiz crashed

I am able to reproduce this issue on Ubuntu 13.04, 13.10. It works fine for me on Ubuntu 12.04, I did not try 12.10.

ProblemType: Crash
DistroRelease: Ubuntu 13.04
Package: unity 7.0.0daily13.06.19~13.04-0ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-32.47-generic 3.8.13.10
Uname: Linux 3.8.0-32-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.9.2-0ubuntu8.5
Architecture: amd64
CrashCounter: 1
Date: Mon Oct 28 20:11:36 2013
ExecutablePath: /usr/bin/compiz
InstallationDate: Installed on 2013-10-08 (20 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
MarkForUpload: True
ProcCmdline: compiz --replace
SegvAnalysis:
 Segfault happened at: 0x7f900a1a2c2d: cmp 0x18(%rax),%r12
 PC (0x7f900a1a2c2d) ok
 source "0x18(%rax)" (0x0000004a) not located in a known VMA region (needed readable region)!
 destination "%r12" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 ?? () from /lib/x86_64-linux-gnu/libc.so.6
 ?? () from /lib/x86_64-linux-gnu/libc.so.6
 XFree () from /usr/lib/x86_64-linux-gnu/libX11.so.6
 ?? () from /usr/lib/compiz/libunityshell.so
 unity::UnityWindow::UnityWindow(CompWindow*) () from /usr/lib/compiz/libunityshell.so
Title: compiz crashed with SIGSEGV in XFree()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

StacktraceTop:
 malloc_consolidate (av=av@entry=0x7f900a4e5740 <main_arena>) at malloc.c:4102
 _int_free (av=0x7f900a4e5740 <main_arena>, p=0x3117de0, have_lock=0) at malloc.c:3994
 XFree (data=<optimized out>) at ../../src/XlibInt.c:1699
 ?? () from /tmp/apport_sandbox_4K5nhw/usr/lib/compiz/libunityshell.so
 unity::UnityWindow::UnityWindow(CompWindow*) () from /tmp/apport_sandbox_4K5nhw/usr/lib/compiz/libunityshell.so

[Will Cooke (willcooke)]

As part of the big bug clear up for 16.04 LTS I am marking this bug as Wont Fix. These types of crasher are better handled by errors.ubutnu.com which can collate similar crash reports to help us identify persitent bugs rather than one-off crashes. Sorry we are not able to help with this specific issue. If you are still experiencing this crash, please re-open the bug and add the tag “desktop-bugscrub-reopen”. See https://wiki.ubuntu.com/BigDesktopBugScrub for more information.