crash due to memory error after g_hash_table_unref from g_slist_foreach

[tadeusz cantwell]

Crashed with package installer open

ProblemType: Crash
DistroRelease: Ubuntu 16.04
Package: mate-panel 1.12.2-1
ProcVersionSignature: Ubuntu 4.4.0-15.31-generic 4.4.6
Uname: Linux 4.4.0-15-generic x86_64
ApportVersion: 2.20-0ubuntu3
Architecture: amd64
CurrentDesktop: MATE
Date: Thu Mar 24 01:05:54 2016
ExecutablePath: /usr/bin/mate-panel
InstallationDate: Installed on 2016-03-23 (0 days ago)
InstallationMedia: Ubuntu-MATE 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160224)
ProcCmdline: mate-panel
ProcEnviron:
 LANGUAGE=en_IE:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_IE.UTF-8
 SHELL=/bin/bash
Signal: 6
SourcePackage: mate-panel
StacktraceTop:
 raise () from /lib/x86_64-linux-gnu/libc.so.6
 abort () from /lib/x86_64-linux-gnu/libc.so.6
 ?? () from /lib/x86_64-linux-gnu/libc.so.6
 ?? () from /lib/x86_64-linux-gnu/libc.so.6
 free () from /lib/x86_64-linux-gnu/libc.so.6
Title: mate-panel crashed with SIGABRT in raise()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
XsessionErrors:
 mate-session[1286]: WARNING: Unable to find provider '' of required component 'dock'
 (mate-panel:1551): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
 (nm-applet:1594): Gdk-CRITICAL **: gdk_window_thaw_toplevel_updates: assertion 'window->update_and_descendants_freeze_count > 0' failed

[Apport retracing service (apport)]

StacktraceTop:
 __libc_message (do_abort=do_abort@entry=2, fmt=fmt@entry=0x7f5ad42adfb8 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
 malloc_printerr (ar_ptr=<optimized out>, ptr=<optimized out>, str=0x7f5ad42aad94 "free(): invalid pointer", action=3) at malloc.c:5007
 _int_free (av=<optimized out>, p=<optimized out>, have_lock=0) at malloc.c:3868
 __GI___libc_free (mem=<optimized out>) at malloc.c:2969
 g_hash_table_unref () from /tmp/apport_sandbox_n5lqNG/lib/x86_64-linux-gnu/libglib-2.0.so.0

[Launchpad Janitor (janitor)]

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

[Launchpad Janitor (janitor)]

[Expired for mate-panel (Ubuntu) because there has been no activity for 60 days.]