[Libreoffice] [REVIEW][PATCH] crash releaseTimer on NULL mpPresTimer

[Caolán McNamara]

http://cgit.freedesktop.org/libreoffice/core/commit/?id=d57887eaad534ca51fc4975918fab66b2f93633d

Reproducer at https://bugzilla.redhat.com/show_bug.cgi?id=759647

I see that the mpPresTimer in slideshow is reset when dispose is called.
However a scopeGuard can still try and call releaseTimer on that
mpPresTimer which was disposed since it the guard ctored. The
boost::cref that scopeGuard takes doesn't increment the shared_ptr, its
effectively just a weak reference.

Fix looks right to me anyway ? Anyone know different, and if not is it
worth cherry-picking for 3-5 ?

C.