Re: pg_xlogdump fails to handle WAL file with multi-page XLP_FIRST_IS_CONTRECORD data

On 1 April 2016 at 21:30, Craig Ringer <craig(at)2ndquadrant(dot)com> wrote:

> I'll attach the new testcase once I either get it to reproduce this bug or
> give up and leave the basic xlogdump testcase alone.
>

I had another bash at this and I still can't reproduce it on master using
the giant commit record approach Andres suggested. In fact I generated a
commit record larger than an entire xlog segment and it was still fine.

The DO procedure I posted upthread, when run on 9.4, reliably produces
segments that the xlogreader cannot decode with the symptoms Pavan
reported. It's fine on 9.6.

So I can't reproduce this on 9.6, but there might be a separate bug on 9.4.

I've attached a patch with the simple tests I added for pg_xlogdump as part
of this. I doubt it'd be desirable to commit the ridiculous commit record
part, but that's trivially removed, and I left it in place in case someone
else wanted to fiddle with other ways to reproduce this.

--
Craig Ringer http://www.2ndQuadrant.com/
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