Re: XML test error on Arch Linux

I wrote:
> I saw that one. It would be good to have a replacement for
> xmlParseBalancedChunkMemory, because after looking at the libxml2
> sources I realize that that's classed as a SAX1 function, which means
> it will likely go away at some point (maybe it's already not there in
> some builds). That's a long-term consideration though.

Actually ... after nosing around in libxml2 some more, I noticed
xmlParseInNodeContext, which is the only other function specified
to parse a Well Balanced Chunk. It requires a context node,
but AFAICS we can just gin up a dummy root node and use that.
It's existed for plenty long enough for our purposes, and it's
not semi-deprecated, and it lacks the bug at hand. So I'm now
thinking about the attached.

As far as the errcontext changes go: I think we have to just bite
the bullet and accept them. It looks like 2.13 has a completely
different mechanism than prior versions for deciding when to issue
XML_ERR_NOT_WELL_BALANCED. And it's not even clear that it's wrong;
for example, in our first failing case

DETAIL: line 1: xmlParseEntityRef: no name
<invalidentity>&</invalidentity>
^
-line 1: chunk is not well balanced
-<invalidentity>&</invalidentity>
- ^

it's kind of hard to argue that the chunk isn't well-balanced.

So we can either suppress errdetails from the expected output,
or set up an additional expected-file. I'm leaning to the
"\set VERBOSITY terse" solution.

regards, tom lane