Remove configure-time probe for DocBook DTD.
Checking for DocBook being installed was valuable when we were on the
OpenSP docs toolchain, because that was rather hard to get installed
fully. Nowadays, as long as you have xmllint and xsltproc installed,
you're good, because those programs will fetch the DocBook files off
the net at need. Moreover, testing this at configure time means that
a network access may well occur whether or not you have any interest
in building the docs later. That can be slow (typically 2 or 3
seconds, though much higher delays have been reported), and it seems
not very nice to be doing an off-machine access without warning, too.
Hence, drop the PGAC_CHECK_DOCBOOK probe, and adjust related
documentation. Without that macro, there's not much left of
config/docbook.m4 at all, so I just removed it.
Back-patch to v11, where we started to use xmllint in the
PGAC_CHECK_DOCBOOK probe.
Discussion: https://postgr.es/m/E2EE6B76-2D96-408A-B961-CAE47D1A86F0@yesql.se
Discussion: https://postgr.es/m/A55A7FC9-FA60-47FE-98B5-139CDC57CE6E@gmail.com
Branch
------
REL_11_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/8d0155962e20c0981a4416b04857b7d997f116a5
Modified Files
--------------
aclocal.m4 | 1 -
config/docbook.m4 | 40 -------------
configure | 137 +++++++++++++++++----------------------------
configure.in | 7 +--
doc/src/sgml/docguide.sgml | 38 +++++++++----
5 files changed, 81 insertions(+), 142 deletions(-)
