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

While reviewing this patch, I started to wonder why we don't eliminate
the maintenance hassle of xml_1.out by putting in a short-circuit
at the top of the test, similar to those in some other scripts:

/* skip test if XML support not compiled in */
SELECT '<value>one</value>'::xml;
\if :ERROR
\quit
\endif

(and I guess xmlmap.sql could get the same treatment).

The only argument I can think of against it is that the current
approach ensures we produce a clean error (and not, say, a crash)
for all xml.c entry points not just xml_in.  I'm not sure how much
that's worth though.  The compiler/linker would tell us if we miss
compiling out every reference to libxml2.

Thoughts?

            regards, tom lane