[RFC] transition to libxml2

[Cyrille Chepelov <chepelov calixo net>]

Hi all,

  while doing my peregrinations in UTF-8 land, I've become convinced that
we'll have to transition to libxml2 to have this right. Of course,
committing highly experimental stuff just before version 0.89 isn't exactly
the best thing to do, so here's what I'm up to, in patch form.

What it does:
        * if using libxml1: using the compat macros recommended by
http://xmlsoft.org
        * if using libxml2: filter blank nodes the "Right Way" (according to
the source above), by using xmlIsBlankNode(). Output files are UTF-8, input
files are converted to UTF-8 on the fly (we cross fingers as to libxml2's
heuristics when the encoding="foo" attribute isn't here). As long as
UNICODE_WORK_IN_PROGRESS is not defined, there's a local/utf8 boundary
between dia's core and the bits of dia which talk XML.

There is one problem (with Debian sid) with libxml2: libgnome-print has been
compiled against libxml1. There's configure.in mojo to check for this
(Debian #97054 made me loose some time... grumpf !)

The patch is at http://traminer.dyndns.org/~cyrille/dia-libxml2.patch.gz
(please bear with my poor 128k link)

Comments ?

        -- Cyrille

-- 
Grumpf.