Date: Sun, 29 Mar 2020 15:15:44 -0700
From: Andres Freund <andres@anarazel.de>
To: Peter Geoghegan <pg@bowt.ie>
Cc: Tom Lane <tgl@sss.pgh.pa.us>,
	pgsql-committers <pgsql-committers@lists.postgresql.org>
Subject: Re: pgsql: Add deduplication to nbtree.
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Hi,

On 2020-03-01 16:09:37 -0800, Peter Geoghegan wrote:
> On Sun, Mar 1, 2020 at 3:01 PM Peter Geoghegan <pg@bowt.ie> wrote:
> > I am happy to add parallel-to-_bt_form_posting() assertions about
> > alignment to _bt_form_posting(), to nail it down completely. Plus I'll
> > add the assertion I suggested already. Once I commit a patch with
> > these two new assertions, I think that we can consider the matter
> > resolved. Does that seem reasonable to you?
> 
> I was thinking of the approach taken in the attached patch. It more or
> less copies over the assertions from _bt_form_posting() that did not
> appear in  _bt_update_posting().

It seems, based on discussion on this thread and private inquiry to PG
that we're going to silence the warning, as there's not a good
resolution? I've for now marked the issue as a false positive, and added
a reference to this thread. But I think we should just mark it as
ignored in that case?

Is it perhaps possible to silence the warnign with somethign along the
lines of
Assert(nhtids + vacposting->ndeletedtids == BTreeTupleGetNPosting(origtuple))
I don't know this code, but it looks like that'd have to be true?
Perhaps that'd be enough to silence coverity too?

- Andres