Re: Fixing code that ignores failure of XLogRecGetBlockTag

On Mon, Apr 11, 2022 at 2:20 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Currently, XLogRecGetBlockTag has 41 callers, of which only four
> bother to check the function's result. The remainder take it on
> faith that they got valid data back, and many of them will
> misbehave in seriously nasty ways if they didn't. (This point
> was drawn to my attention by a Coverity complaint.)
>
> I think we should make this a little less fragile. Since we
> already have XLogRecGetBlockTagExtended, I propose that callers
> that need to handle the case of no-such-block must use that,
> while XLogRecGetBlockTag throws an error. The attached patch
> fixes that up, and also cleans up some random inconsistency
> about use of XLogRecHasBlockRef().

Looks reasonable.

--
Robert Haas
EDB: http://www.enterprisedb.com