ext/xml: libexpat support still useful?

Morning Christoph,

It is not clear what has been deprecated:

21 June 2016, Expat 2.2.2 released

Can you dig about some more and find out what's going on exactly please ?

Originally, ext/xml relied solely on libexpat[1], but in PHP 5 it was
rewritten to support also libxml[2] (apparently, all XML extensions had
been rewritten to support libxml back then[3]). The reason to switch to
libxml apparently was to have a common backend for all XML extensions[4].

The deprecation notice was introduced in commit 73415c9e[5] which was
about removing the bundled libexpat. I don't know whether there had
been any plans to remove libexpat support altogether sometime (and this
had simply be forgotten), or the deprecation notice had only been
introduced to express that libxml is preferred.

[1] https://github.com/php/php-src/blob/PHP-4.4/ext/xml/config.m4
[2] https://github.com/php/php-src/blob/PHP-5.0/ext/xml/config.m4
[3] https://www.mail-archive.com/internals@lists.php.net/msg11050.html
[4] https://www.mail-archive.com/internals@lists.php.net/msg03676.html
[5]
https://github.com/php/php-src/commit/73415c9e#diff-eaaec22f50f9d41395bbe856ae4c5723

Cheers,
Christoph

Cheers
Joe

[1] http://www.libexpat.org/

On Sun, Jan 8, 2017 at 11:02 PM, Christoph M. Becker cmbecker69@gmx.de
wrote:

Hi!

Due to https://bugs.php.net/71595 I've noticed:

$ ./configure --help | grep expat | grep XML:
--with-libexpat-dir=DIR XML: libexpat install prefix (deprecated)

This deprecation note is apparently present as of PHP 5.0.0 at least.
So I wonder whether there's a good reason to still support libexpat,
especially as some behavior of the XML extension depends on the
underlying library. It seems to me we could reduce the maintaince
burden by removing libexpat support altogether.

Thoughts?

--
Christoph M. Becker