I don't have the technical expertise to report this properly, but my own experience (after upgrading mesa to 17.3.1) and the crashes reported by other users of Firefox, it seems that 17.3.1 has introduced a bug that occasionally will cause Firefox to crash on i965 hardware:
Just a wild guess, but maybe it's related to this change?
Could you share your cpu info, graphics, distro and desktop enviroment? Also could you take a time to find a way to reliably trigger this? It will be really helpful to find a root-cause.
Most likely a duplicate of bug 104214. See comment 29 there for a patch if you want to test the fix.
Thanks, it does appear to have been a duplicate.
*** This bug has been marked as a duplicate of bug 104214 ***