Re: libpq debug log

At Fri, 2 Apr 2021 02:56:44 +0000, "iwata.aya@fujitsu.com" <iwata.aya@fujitsu.com> wrote in 
> Hi Alvaro san
> 
> Thank you for your fix of trace log code.
> 
> > From: 'alvherre@alvh.no-ip.org' <alvherre@alvh.no-ip.org>
> > Sent: Friday, April 2, 2021 11:30 AM
> ...
> > It still didn't fix it!  Drongo is now reporting a difference in the expected trace --
> > and the differences all seem to be message lengths.
> > Now that is pretty mysterious, because the messages themselves are printed
> > identically.  Perl's output is pretty unhelpful, but I wrote them to a file and diffed
> > manually; it's attached.
>
> Do ErrorResponse and NoticeResponse vary from test to test ...?
> If so, it seemed difficult to make the trace logs available for regression test. 
> I will also investigate the cause of this issue.

The redacted fields, F, L and R contained source file, souce line and
source function respectively. It is reasonable guess that the
difference comes from them but I'm not sure how they make a difference
of 50 bytes in length...

Anyway if the length is wrong, we should get an error after emitting
the log line.

>    if (logCursor - 1 != length)
>        fprintf(conn->Pfdebug,
>                "mismatched message length: consumed %d, expected %d\n",
>                logCursor - 1, length);

So, the cheapest measure for regression test would be just making the
length field, while regress is true...

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center