Re: BUG #8821: pg_trgm segfault with Turkish locale database

Ufuk Kayserilioglu <ufuk(at)paralaus(dot)com> writes:
> Thanks for the quick response. Just a quick followup note though; running:

> SELECT show_trgm(maker) FROM car_makers;

> behaves properly, but trying to make a similarity comparison triggers the segfault (at least in my case). That's why I suspect there may be 2 related bugs, one related trigram generation and, maybe, one related to trigram comparison. Hope this info will help you as well.

The given cases all work for me with the committed patch to generate_trgm(),
http://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=c3ccc9ee584b9b015dd9c1931e261e21f3961e5f

I'm not going to sit here and claim that there are now zero bugs in
pg_trgm, but I'm not seeing evidence of a second issue. Since the bug is
a buffer overrun of just a few bytes, whether it results in a crash in any
particular trigram operation is hard to predict; it might just stomp on
noncritical memory.

regards, tom lane