Re: Memory leak in WAL sender with pgoutput (v10~)

On Tue, Dec 03, 2024 at 02:45:22PM +0100, Alvaro Herrera wrote:
> We can put the new member at the end of the struct, it shouldn't damage
> anything even if they're using this struct -- which I find pretty
> unlikely. The only way that could break anything is if somebody is
> allocating/using arrays of it, which sounds even more unlikely.

Yes, that sounds unlikely.

> If we don't want to accept that risk (for which I see no argument, but
> happy to be proven wrong), I would suggest to use the foreach-pfree
> pattern Michael first proposed for the backbranches, and the new memory
> context in master. I think this is conducive to better coding overall
> as we clean things up in this area.

Is it really worth betting on nobody doing something that does a
sizeof(PGOutputData) for the stable branches? People like doing fancy
things, and we would not hear about such problems except if we push
the button making it a possibility because compiled code suddenly
breaks after a minor release update of the core engine.
--
Michael