Horton

Re: fix for BUG #3720: wrong results at using ltree

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Filip Rembiałkowski <filip.rembialkowski@gmail.com>, Pgsql Hackers <pgsql-hackers@postgresql.org>, Teodor Sigaev <teodor@sigaev.ru>, Oleg Bartunov <obartunov@postgrespro.ru>
Date: 2019-07-08T04:22:16Z
Lists: pgsql-hackers 
On Sun, Apr 7, 2019 at 3:46 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> =?UTF-8?Q?Filip_Rembia=C5=82kowski?= <filip.rembialkowski@gmail.com> writes:
> > Here is my attempt to fix a 12-years old ltree bug (which is a todo item).
> > I see it's not backward-compatible, but in my understanding that's
> > what is documented. Previous behavior was inconsistent with
> > documentation (where single asterisk should match zero or more
> > labels).
> > http://archives.postgresql.org/pgsql-bugs/2007-11/msg00044.php

[...]

> In short, I'm wondering if we should treat this as a documentation
> bug not a code bug.  But to do that, we'd need a more accurate
> description of what the code is supposed to do, because the statement
> quoted above is certainly not a match to the actual behavior.

This patch doesn't apply.  More importantly, it seems like we don't
have a consensus on whether we want it.

Teodor, Oleg, would you like to offer an opinion here?  If I
understand correctly, the choices are doc change, code/comment change
or WONT_FIX.  This seems to be an entry that we can bring to a
conclusion in this CF with some input from the ltree experts.

-- 
Thomas Munro
https://enterprisedb.com

Commits

  1. Back-patch addition of stack overflow and interrupt checks for lquery.

  2. Fix lquery's NOT handling, and add ability to quantify non-'*' items.

  3. Improve error messages in ltree_in and lquery_in.

  4. Fix lquery's behavior for consecutive '*' items.

  5. Protect against overflow of ltree.numlevel and lquery.numlevel.