Re: Calling xlst_process with certain arguments causes server crash

I wrote:
> Hm, apparently xsltApplyStylesheet returns a NULL in this example,
> and we're passing that on to xsltSaveResultToString which is not
> expecting any such thing.  I presume we need another error check
> here, but what should the error say exactly?  Can we get any info
> more detailed than "failed to apply stylesheet"?

Apparently not -- or at least, if libxslt provides any easy way to
extract error reports, it's not evident from the pretty-awful
documentation.  I've committed a fix that just reports "failed to apply
stylesheet".

            regards, tom lane