Subject: bug#20802: Segfault when showing non-GTK+ tooltip

From: martin rudalics <[email-masked]>
Date: Tue, 16 Jun 2015 15:30:28 +0200

> This was after setting x-gtk-use-system-tooltip to nil and customizing
 > the tooltip face to #qqq.
[...]
 > Program received signal SIGSEGV, Segmentation fault.
 > cache_image (f=0x1170a68, img=<optimized out>) at image.c:1782
 > 1782	  for (i = 0; i < c->used; ++i)

This should be indeed the same segfault I saw.  Meanwhile I checked in a
fix on trunk/master.  If you can build Emacs please try it.

Thanks for report and backtrace, martin