(gdb) bt
#0  0x00002aaaab2a0107 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x00002aaaab2a14e8 in __GI_abort () at abort.c:89
#2  0x00002aaaab299226 in __assert_fail_base (fmt=0x2aaaab3cf968 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", 
    assertion=assertion@entry=0x2aaab1ed8c80 "nX < mpBuffer->mnWidth && \"x-coordinate out of range!\"", 
    file=file@entry=0x2aaab1ed8bd8 "/home/julien/compile-libreoffice/libo_4_4/include/vcl/bmpacc.hxx", line=line@entry=416, 
    function=function@entry=0x2aaab1ed94c0 <BitmapWriteAccess::SetPixel(long, long, BitmapColor const&)::__PRETTY_FUNCTION__> "void BitmapWriteAccess::SetPixel(long int, long int, const BitmapColor&)") at assert.c:92
#3  0x00002aaaab2992d2 in __GI___assert_fail (assertion=0x2aaab1ed8c80 "nX < mpBuffer->mnWidth && \"x-coordinate out of range!\"", 
    file=0x2aaab1ed8bd8 "/home/julien/compile-libreoffice/libo_4_4/include/vcl/bmpacc.hxx", line=416, 
    function=0x2aaab1ed94c0 <BitmapWriteAccess::SetPixel(long, long, BitmapColor const&)::__PRETTY_FUNCTION__> "void BitmapWriteAccess::SetPixel(long int, long int, const BitmapColor&)") at assert.c:101
#4  0x00002aaab197e001 in BitmapWriteAccess::SetPixel (this=0x2c8f970, nY=0, nX=137, rBitmapColor=...) at /home/julien/compile-libreoffice/libo_4_4/include/vcl/bmpacc.hxx:416
#5  0x00002aaab19def03 in Bitmap::ImplConvolutionPass (this=0x7fffffff32d0, aNewBitmap=..., nNewSize=182, pReadAcc=0x3789210, aNumberOfContributions=3, pWeights=0x2d26ef0, 
    pPixels=0x35c6450, pCount=0x332a940) at /home/julien/compile-libreoffice/libo_4_4/vcl/source/gdi/bitmap3.cxx:2627
#6  0x00002aaab19e6091 in Bitmap::ImplSeparableBlurFilter (this=0x7fffffff32d0, radius=0.69999999999999996)
    at /home/julien/compile-libreoffice/libo_4_4/vcl/source/gdi/bitmap4.cxx:1102
#7  0x00002aaab19e0328 in Bitmap::Filter (this=0x7fffffff32d0, eFilter=BMP_FILTER_SMOOTH, pFilterParam=0x7fffffff32a0, pProgress=0x0)
    at /home/julien/compile-libreoffice/libo_4_4/vcl/source/gdi/bitmap4.cxx:52
#8  0x00002aaab19f4f8b in BitmapEx::Filter (this=0x7fffffff32d0, eFilter=BMP_FILTER_SMOOTH, pFilterParam=0x7fffffff32a0, pProgress=0x0)
    at /home/julien/compile-libreoffice/libo_4_4/vcl/source/gdi/bitmapex.cxx:653
#9  0x00002aaae2653d3f in GraphicFilterSmooth::GetFilteredGraphic (this=0x447e590, rGraphic=...)
    at /home/julien/compile-libreoffice/libo_4_4/cui/source/dialogs/cuigrfflt.cxx:280
#10 0x00002aaae2653217 in GraphicFilterDialog::ImplPreviewTimeoutHdl (this=0x447e590) at /home/julien/compile-libreoffice/libo_4_4/cui/source/dialogs/cuigrfflt.cxx:162
#11 0x00002aaae2653181 in GraphicFilterDialog::LinkStubImplPreviewTimeoutHdl (pThis=0x447e590, pCaller=0x447e888)
    at /home/julien/compile-libreoffice/libo_4_4/cui/source/dialogs/cuigrfflt.cxx:158
#12 0x00002aaab16c01b4 in Link::Call (this=0x447e8a8, pCaller=0x447e888) at /home/julien/compile-libreoffice/libo_4_4/include/tools/link.hxx:139
#13 0x00002aaab1c2140d in Timer::Timeout (this=0x447e888) at /home/julien/compile-libreoffice/libo_4_4/vcl/source/app/timer.cxx:276
#14 0x00002aaab1c21ae6 in ImplTimerData::Invoke (this=0x328a720) at /home/julien/compile-libreoffice/libo_4_4/vcl/source/app/timer.cxx:54
#15 0x00002aaab1c21076 in Timer::ImplTimerCallbackProc () at /home/julien/compile-libreoffice/libo_4_4/vcl/source/app/timer.cxx:162
#16 0x00002aaabf23871b in SalTimer::CallCallback (this=0x29d0030) at /home/julien/compile-libreoffice/libo_4_4/vcl/inc/saltimer.hxx:53
#17 0x00002aaabf237cc3 in sal_gtk_timeout_dispatch (pSource=0x518f490) at /home/julien/compile-libreoffice/libo_4_4/vcl/unx/gtk/app/gtkdata.cxx:833
#18 0x00002aaab7c22b6d in g_main_dispatch (context=0x27b1d90) at /tmp/buildd/glib2.0-2.42.1/./glib/gmain.c:3111
#19 g_main_context_dispatch (context=context@entry=0x27b1d90) at /tmp/buildd/glib2.0-2.42.1/./glib/gmain.c:3710
#20 0x00002aaab7c22f48 in g_main_context_iterate (context=context@entry=0x27b1d90, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /tmp/buildd/glib2.0-2.42.1/./glib/gmain.c:3781
#21 0x00002aaab7c22ffc in g_main_context_iteration (context=0x27b1d90, may_block=1) at /tmp/buildd/glib2.0-2.42.1/./glib/gmain.c:3842
#22 0x00002aaabf237055 in GtkData::Yield (this=0x643b60, bWait=true, bHandleAllCurrentEvents=false)
    at /home/julien/compile-libreoffice/libo_4_4/vcl/unx/gtk/app/gtkdata.cxx:575
#23 0x00002aaabf23af02 in GtkInstance::Yield (this=0x6331f0, bWait=true, bHandleAllCurrentEvents=false)