On 24 May 2012 16:08, Robert Haas <robertmhaas@gmail.com> wrote:
> On Thu, May 24, 2012 at 10:16 AM, Marko Kreen <markokr@gmail.com> wrote:
>> Following query crashes backend on 9.2:
>>
>> select substring('asd TO foo' from ' TO (([a-z0-9._]+|"([^"]+|"")+")+)');
>
> I spent some time trying to reduce this to the simplest case that
> still causes a crash, and came up with this:
>
> select substring('a' from '((a))+');
It appears to occur with any quantifier attached to a group that is
more than 1 level deep with nothing between the groups, such as
((a))?, ((a))*, ((a)){1,4}, (((a)))+
Or if the quantifier is the only additional thing between the groups,
such as ((a)+)
But when breaking the groups up, it's fine, so this works: ((a)b)+
--
Thom