Heads up, small incompatibility with upcoming libxml2-2.9.0

[Daniel Veillard]

  Hello everybody,

I just made a build in Rawhide of libxml2-2.9.0-0rc1.fc19, the first
release candidate for the upcoming libxml2-2.9.0 release, I'm targetting
a final release beginning of September.

This release introduce a small API incompatibility which may affect a
few package, among others libxslt, php, python-lxml, gcc libjava and
evolution-data-server, all of which should have the patches needed
upstream already. More information may be found in the libxml2 and
GNOME mailing-lists, basically a structure which used to be exposed
at the API level is now opaque for refactoring. That change was made
mosly for security reasons:

  https://mail.gnome.org/archives/xml/2012-August/msg00005.html
  https://mail.gnome.org/archives/desktop-devel-list/2012-August/msg00007.html

Out of the hundreds of packages relying on libxml2 I expect only a few
more who might be affected by the change, this can show up at
compilation time with an error about accessing an undefined buf
structure. Grab me I will be more than happy to help fixing the
problem and getting the patch ready for upstream !

The ABI emulation should work fine at this point, I have been running
my Fedora 17 with the updated package without noticing any problem for
nearly a week now, even libxslt/xsltproc which probably push the limits
of libxml2 APIs works fine, so I'm relatively confident on the current
state.

  One thing I'm unclear about is the best way to get this into Fedora
18, should I try to push the release candidate now to find out which
packages need fixing at the code level if we do other mass rebuilds
before GA, or should I wait until 2.9.0 is out in a few weeks, possibly
relying on the binary compatibility if the affected packages are not
rebuilt,

   Any opinion on the best way ?

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/