Re: [PATCH] Add pretty-printed XML output option

On 15.03.23 22:13, Tom Lane wrote:
> I wrote:
> It occurred to me to test v23 for memory leaks, and it had bad ones:
> * the "newline" node used in the CONTENT case never got freed.
> Making another one for each line wasn't helping, either.
Oh, I did really miss that one. Thanks!
> Pushed with those changes and some other cosmetic cleanup.
> Thanks for working so hard on this!
Great! Thank you, Peter and Andrey for the very nice reviews.
> BTW, the libxml leak problem seems to extend to other cases too.
> I tested with code like
>
> do $$
> declare x xml; t text;
> begin
> x := '<?xml version="1.0" encoding="utf8"?><foo><bar><val>73</val></bar></foo>';
> for i in 1..10000000 loop
> t := xmlserialize(document x as text);
> end loop;
> raise notice 't = %', t;
> end;
> $$;
>
> That case is fine, but if you change the encoding spec to "latin1",
> it leaks like mad. That problem is not the fault of this patch,
> I don't think. I wonder if we need to do something to prevent
> libxml from seeing encoding declarations other than utf8?

In my environment (libxml2 v2.9.10 and Ubuntu 22.04) I couldn't
reproduce this memory leak. It's been most likely fixed in further
libxml2 versions. Unfortunately their gitlab page has no release notes
from versions prior to 2.9.13 :(

Best, Jim