Comment # 18 on bug 1015998 from Robert Walker

I've encountered this bug on my Gentoo build of firefox, using the OpenSUSE
patchset. Tested, and present, with all versions of kmozillahelper 4.9.9-5.0.0
along with firefox 51.0 ...

To add to this report - the segmentation fault only occurs if the experimental
e10 / electrolysis feature is enabled (another user reported this on the
kmozillahelper Github page -  I can confirm this). See:
https://github.com/openSUSE/kmozillahelper/issues/8

If e10 support is disabled. The Cancel button - in the kmozillahelper
QFileDialog - behaves as expected.