errordocument conflicts with trac

[Gijs van Dulmen]

I'm running Trac 0.9 with Mod Python and noticed something odd. I don't know however if this is Trac related, but it sure doesn't work in a way I thought it would be.

Running Debian.

apache2 -v output:

Server version: Apache/2.0.54
Server built:   Sep  5 2005 11:11:08

Trac-admin output: trac-admin - The Trac Administration Console 0.9

Mod python version is 3.1.3

Apache2 config part which creates the odd situation:

<IfModule mod_negotiation.c>
<IfModule mod_include.c>
    Alias /error/ "/usr/share/apache2/error/"

    <Directory "/usr/share/apache2/error">
        AllowOverride None
        Options IncludesNoExec
        AddOutputFilter Includes html
        AddHandler type-map var
        Order allow,deny
        Allow from all
        LanguagePriority en es de fr
        ForceLanguagePriority Prefer Fallback
    </Directory>

    ErrorDocument 400 /error/HTTP_BAD_REQUEST.html.var
    ErrorDocument 401 /error/HTTP_UNAUTHORIZED.html.var
    ErrorDocument 403 /error/HTTP_FORBIDDEN.html.var
    ErrorDocument 404 /error/HTTP_NOT_FOUND.html.var
    ErrorDocument 405 /error/HTTP_METHOD_NOT_ALLOWED.html.var
    ErrorDocument 408 /error/HTTP_REQUEST_TIME_OUT.html.var
    ErrorDocument 410 /error/HTTP_GONE.html.var
    ErrorDocument 411 /error/HTTP_LENGTH_REQUIRED.html.var
    ErrorDocument 412 /error/HTTP_PRECONDITION_FAILED.html.var
    ErrorDocument 413 /error/HTTP_REQUEST_ENTITY_TOO_LARGE.html.var
    ErrorDocument 414 /error/HTTP_REQUEST_URI_TOO_LARGE.html.var
    ErrorDocument 415 /error/HTTP_SERVICE_UNAVAILABLE.html.var
    ErrorDocument 500 /error/HTTP_INTERNAL_SERVER_ERROR.html.var
    ErrorDocument 501 /error/HTTP_NOT_IMPLEMENTED.html.var
    ErrorDocument 502 /error/HTTP_BAD_GATEWAY.html.var
    ErrorDocument 503 /error/HTTP_SERVICE_UNAVAILABLE.html.var
    ErrorDocument 506 /error/HTTP_VARIANT_ALSO_VARIES.html.var

</IfModule>
</IfModule>

I use this apache virtual host config for trac:

<VirtualHost *:443>
	ServerName sub.domain.com
	DocumentRoot /var/www/sub.domain.com/

	SSLEngine On
	SSLCertificateFile /etc/apache2/ssl/apache.pem
	SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown 
	SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL

	SSLOptions +StdEnvVars

	Alias /trac /usr/share/trac/htdocs/ 
    <Location />
        SetHandler mod_python
	PythonHandler trac.web.modpython_frontend 
	PythonOption TracEnv /var/www/sub.domain.com
        PythonOption TracUriRoot /
	suPHP_Engine Off
	SecFilterEngine Off
</Location>
    <Location /login>
 		AuthType Basic
		AuthName "Trac - Project Management and Version Control"
		AuthUserFile /etc/apache2/.htpasswd-svn
		Require valid-user
		SecFilterEngine Off
    </Location>
<Location /trac>
	      SetHandler None
	        </Location>

	ErrorLog /var/log/apache2/error.log
	CustomLog /var/log/apache2/access.log combined
	LogLevel warn

</VirtualHost>

When I have it like this Trac issues this error when I want to login:

No handler matched request to /error/HTTP_UNAUTHORIZED.html.var 

When I comment out this line in the apache config part:

ErrorDocument 401 /error/HTTP_UNAUTHORIZED.html.var

It works OK.

A workaround which I got is adding this line in my virtualhost:

ErrorDocument 401 default

Then things will work Ok.

Hope someone can research this.

[Matthew Good]

(fixing description)

The workaround suggested above seems reasonable since a 401 response will prompt the browser to display a login dialog so the page would never be seen by a user.

I guess another option is for Trac to provide a request handler for /error/HTTP_UNAUTHORIZED.html.var that would simply return a 401 response. I think we'll need to check with some Apache devs on this to see if there's a cleaner solution.