Re: Alignment padding bytes in arrays vs the planner

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>
To: Noah Misch <noah@leadboat.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers@postgresql.org
Date: 2011-05-24T18:05:33Z
Lists: pgsql-hackers
On Mon, May 23, 2011 at 1:12 AM, Noah Misch <noah@leadboat.com> wrote:
> On Tue, Apr 26, 2011 at 11:51:35PM -0400, Noah Misch wrote:
>> On Tue, Apr 26, 2011 at 07:23:12PM -0400, Tom Lane wrote:
>> [input functions aren't the only problematic source of uninitialized datum bytes]
>>
>> > We've run into other manifestations of this issue before.  Awhile ago
>> > I made a push to ensure that datatype input functions didn't leave any
>> > ill-defined padding bytes in their results, as a result of similar
>> > misbehavior for simple constants.  But this example shows that we'd
>> > really have to enforce the rule of "no ill-defined bytes" for just about
>> > every user-callable function's results, which is a pretty ugly prospect.
>>
>> FWIW, when I was running the test suite under valgrind, these were the functions
>> that left uninitialized bytes in datums: array_recv, array_set, array_set_slice,
>> array_map, construct_md_array, path_recv.  If the test suite covers this well,
>> we're not far off.  (Actually, I only had the check in PageAddItem ... probably
>> needed to be in one or two other places to catch as much as possible.)
>
> Adding a memory definedness check to printtup() turned up one more culprit:
> tsquery_and.

*squints*

OK, I can't see what's broken.  Help?

-- 
Robert Haas
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