Is this reproducible? If so, can you attach or link to this file, or provide another one which causes the crash? What unrar version is being used?

Yes this is reproducible, its happening on all zip and rar files, that I have tested.

Right, then please attach one of these files here, and tell which unrar and unzip versions you are using.

dpkg-query -l unzip
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name           Version        Description
+++-==============-==============-============================================
ii  unzip          6.0-4ubuntu1   De-archiver for .zip files


dodo@elcrapo:~/Downloads/$ unzip -h
UnZip 6.00 of 20 April 2009, by Debian. Original by Info-ZIP.

File I tried to extract which crashed is available here: http://technorumor.blogspot.com.au/2012/03/download-chrome-os-default-wallpapers.html

its a set of wallpapers.

The latest crash with todays update for project neon with the above zip file

Application: Ark (ark), signal: Aborted
[KCrash Handler]
#7  0xb76e8424 in __kernel_vsyscall ()
#8  0xb58efc8f in __GI_raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#9  0xb58f32b5 in __GI_abort () at abort.c:92
#10 0xb5bbb4f7 in qt_message_output (msgType=QtFatalMsg, buf=0x92e26b8 "ASSERT: \"!m_process\" in file /build/buildd/project-neon-ark-2+git20120528+r2445/kerfuffle/cliinterface.cpp, line 78") at global/qglobal.cpp:2264
#11 0xb5bbb696 in qt_message (msgType=QtFatalMsg, msg=0xb5d605f4 "ASSERT: \"%s\" in file %s, line %d", ap=0xbfd47d44 "R\252m\267P\251m\267N") at global/qglobal.cpp:2310
#12 0xb5bbbac2 in qFatal (msg=0xb5d605f4 "ASSERT: \"%s\" in file %s, line %d") at global/qglobal.cpp:2493
#13 0xb5bbb0ae in qt_assert (assertion=0xb76daa52 "!m_process", file=0xb76da950 "/build/buildd/project-neon-ark-2+git20120528+r2445/kerfuffle/cliinterface.cpp", line=78) at global/qglobal.cpp:2011
#14 0xb76d0e60 in Kerfuffle::CliInterface::~CliInterface (this=0x92c74f8, __in_chrg=<optimized out>) at /build/buildd/project-neon-ark-2+git20120528+r2445/kerfuffle/cliinterface.cpp:78
#15 0xb3825295 in CliPlugin::~CliPlugin (this=0x92c74f8, __in_chrg=<optimized out>) at /build/buildd/project-neon-ark-2+git20120528+r2445/plugins/clizipplugin/cliplugin.cpp:43
#16 0xb38252cf in CliPlugin::~CliPlugin (this=0x92c74f8, __in_chrg=<optimized out>) at /build/buildd/project-neon-ark-2+git20120528+r2445/plugins/clizipplugin/cliplugin.cpp:45
#17 0xb5cfef28 in QObjectPrivate::deleteChildren (this=0x91225b0) at kernel/qobject.cpp:1908
#18 0xb5cfd840 in QObject::~QObject (this=0x92be1d8, __in_chrg=<optimized out>) at kernel/qobject.cpp:927
#19 0xb76c1e97 in Kerfuffle::Archive::~Archive (this=0x92be1d8, __in_chrg=<optimized out>) at /build/buildd/project-neon-ark-2+git20120528+r2445/kerfuffle/archive.cpp:131
#20 0xb76c1ed1 in Kerfuffle::Archive::~Archive (this=0x92be1d8, __in_chrg=<optimized out>) at /build/buildd/project-neon-ark-2+git20120528+r2445/kerfuffle/archive.cpp:133
#21 0xb5cfef28 in QObjectPrivate::deleteChildren (this=0x926a880) at kernel/qobject.cpp:1908
#22 0xb5cfd840 in QObject::~QObject (this=0x92728f0, __in_chrg=<optimized out>) at kernel/qobject.cpp:927
#23 0xb5faf2cb in KJob::~KJob (this=0x92728f0, __in_chrg=<optimized out>) at /build/buildd/project-neon-kdelibs-2+git20120608+r92761/kdecore/jobs/kjob.cpp:65
#24 0xb5fae2db in KCompositeJob::~KCompositeJob (this=0x92728f0, __in_chrg=<optimized out>) at /build/buildd/project-neon-kdelibs-2+git20120608+r92761/kdecore/jobs/kcompositejob.cpp:42
#25 0x0804f6d3 in BatchExtract::~BatchExtract (this=0x92728f0, __in_chrg=<optimized out>) at /build/buildd/project-neon-ark-2+git20120528+r2445/app/batchextract.cpp:60
#26 0x0804f6fd in BatchExtract::~BatchExtract (this=0x92728f0, __in_chrg=<optimized out>) at /build/buildd/project-neon-ark-2+git20120528+r2445/app/batchextract.cpp:65
#27 0xb5d03d5b in qDeleteInEventHandler (o=0x92728f0) at kernel/qobject.cpp:4277
#28 0xb5cfdd40 in QObject::event (this=0x92728f0, e=0x92aa268) at kernel/qobject.cpp:1176
#29 0xb62fb10c in QApplicationPrivate::notify_helper (this=0x9121c98, receiver=0x92728f0, e=0x92aa268) at kernel/qapplication.cpp:4551
#30 0xb62f8a0a in QApplication::notify (this=0xbfd48860, receiver=0x92728f0, e=0x92aa268) at kernel/qapplication.cpp:3933
#31 0xb6fe88c6 in KApplication::notify (this=0xbfd48860, receiver=0x92728f0, event=0x92aa268) at /build/buildd/project-neon-kdelibs-2+git20120608+r92761/kdeui/kernel/kapplication.cpp:311
#32 0xb5ce6e72 in QCoreApplication::notifyInternal (this=0xbfd48860, receiver=0x92728f0, event=0x92aa268) at kernel/qcoreapplication.cpp:915
#33 0xb5cea5d9 in QCoreApplication::sendEvent (receiver=0x92728f0, event=0x92aa268) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#34 0xb5ce7d6e in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x9102370) at kernel/qcoreapplication.cpp:1539
#35 0xb5ce7a2b in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1432
#36 0xb5d1e630 in QCoreApplication::sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236
#37 0xb5d1d7ae in postEventSourceDispatch (s=0x9122a30) at kernel/qeventdispatcher_glib.cpp:279
#38 0xb4eca73a in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#39 0xb4ecab45 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#40 0xb4ecac21 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#41 0xb5d1df60 in QEventDispatcherGlib::processEvents (this=0x9102ed8, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#42 0xb63c4768 in QGuiEventDispatcherGlib::processEvents (this=0x9102ed8, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#43 0xb5ce45fd in QEventLoop::processEvents (this=0xbfd4879c, flags=...) at kernel/qeventloop.cpp:149
#44 0xb5ce476b in QEventLoop::exec (this=0xbfd4879c, flags=...) at kernel/qeventloop.cpp:204
#45 0xb5ce74ee in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1187
#46 0xb62f867e in QApplication::exec () at kernel/qapplication.cpp:3812
#47 0x08055189 in main (argc=5, argv=0xbfd48c14) at /build/buildd/project-neon-ark-2+git20120528+r2445/app/main.cpp:209

Hmm, this looks similar to bug 304067, and it also reminds me of bug 304764 (with the difference that this one fails due to a corrupted archive).

I've been trying to reproduce this crash for some time but haven't been able to do so. Do you still have this problem when extracting zip/rar files via Dolphin's context menu? Does running "ark -bea <archive>" from a terminal always crash the same way for you?

Git commit e21c15b3e048178a8fa7e13e2734d8988221031f by Raphael Kubo da Costa.
Committed on 17/08/2012 at 10:04.
Pushed by rkcosta into branch 'KDE/4.9'.

Delete m_process earlier.

Deleting and setting m_process to 0 at the end of runProcess() is
sometimes too late.

If one connects to KJob::result() to delete an archive interface, that
is all going to happen when finished() is emitted in processFinished()
and before `delete m_process' is called in runProcess(). This ends up
leaving us with a non-NULL m_process, causing the assert in
CliInterface's destructor to fail.

Delete m_process and set it to 0 in processFinished() itself, since it
is not supposed to be used afterwards anyway.
Related: bug 304067
FIXED-IN: 4.9.1

M  +4    -2    kerfuffle/cliinterface.cpp

http://commits.kde.org/ark/e21c15b3e048178a8fa7e13e2734d8988221031f