using ProxyHTMLEnable On, mod_proxy_html or xml2enc segfaults (Apache Users)

2009/10/29 Nick Kew <nick@xxxxxxxxxxxx>

2009/10/28 Martin Gerdes <martingrds@xxxxxxxxxxxxxx>

Background:
I am running Apache as provided for Debian Lenny (2.2.9-10+lenny4) as
a reverse proxy. To that end, I installed libapache2-mod-proxy-html
(3.0.0-1) for URL rewriting.
As the original content is in charset ISO-8859-1, I set the option
"ProxyHTMLCharsetOut *" to get the webpage output as ISO-8859 instead
of UTF-8.

Everything worked just fine, except that a certain packet crashed the
proxy-html module (Paket went into the proxy, no paket came out;
according to the log, a process crashed at precisely that time...)

I emailed the developer, who advised me to try the most recent version
(3.1.2) for which unfortunately no debian package exists. So I spent
half a day figuring out how to update the source debian archive with
the most recent source code. I managed it, installed it, and it
worked, and the module did not crash anymore. :-)

Hmmm, I thought I advised getting me a test case that could reproduce
the crash, and your email on Oct 26th said the problem had gone.

Alright, so I simplified a bit :-)
The problem IS gone with the new version. I just failed to check whether the conversion was still happening - which it turns out it wasn't. That should have no bearing on the crash though, as the conversion back to ISO-8859-1 happens after the links are replaced.

However, after continuing to play around with mod-proxy-html I noticed
that the output stays as utf-8 (having been converted from ISO-8859-1)
instead of being converted back to ISO-8859-1.
Note that 3.0.0 worked with precisely the same configuration (except
that it did not need xml2enc).

Precisely the same configuration would be incorrect. You need to switch
from using apache's generic filter configuration to the new

ProxyHTMLEnable directive. Hence the bold
Important Note: Configuration has changed:
on its front page.

But maybe you've found a docs bug, and I need to add the note

in more places, for existing users who don't check what you
already know about! Where did you check?