Re: %d in log_line_prefix doesn't work for bg/autovacuum workers

Andres Freund <andres@2ndquadrant.com> writes:
> On 2014-05-16 14:02:44 -0400, Tom Lane wrote:
>> Not directly related to your gripe, but: where did this "padding" logic
>> come from, and what prevents it from creating invalidly-encoded output by
>> means of truncating multibyte characters in the middle?

> Isn't that syntax just the *minimal* width?

Ah, you're right, so sprintf shouldn't attempt to truncate the data
anywhere.  Nonetheless, this has created a hazard that wasn't there
before: with any padding spec, sprintf has to determine the
width-in-characters of the supplied string.  If glibc thinks the data
is invalid according to *its* idea of the prevailing encoding, it will
do something we won't like.  My recollection is it refuses to print
anything at all.
        regards, tom lane