Task: Document disabling the URI check

That message is designed to help you debug server problems, which you apparently have. I know nothing about IIS.

Domain Access tries to load a sample image from a known location when you are configuring a domain.

If this problem persists after an uninstall, it suggests larger problems at the IIS level, or an incomplete uninstall.

I think that this needs to be configurable as it fails with HTTP restrictions. Also, I've worked on servers that can not do HTTP requests to themselves (I think that the dns was pointing to the external IP that didn't resolve to the internal IP - a strange issue that we worked around rather than resolving.)

So this patch adds a configuration setting to bypass the check, with a very bold warning attached to it. If this is too much, can you consider removing the UI but leaving the variable so that developers can set this manually themselves if required?

I did something similar on.a project recently. It didn't suppress the warnings, but let you ignore them.

A documented $conf settting seems reasonable here. My problem is that I can't reliably test these edge cases.

Still not major.

It is major when you are developing on a public server with sensitive data! Anyways, easy to test, just password protect a directory using the .htaccess file, this will block the request and generate a fail.

I was referring specifically to the odd error code reported by the OP.

I'm tempted to add this simply as a hidden variable that can be overridden in $conf. I don't think we want to expose this in the settings UI and give people the chance to shoot themselves in the foot.

And a version with a warning.

Here's what the warning displays.

Looks good. The hidden settings are used in a number of places, so I think that no one would argue about it :)

I'm going to commit this.

Can you follow-up with documentation here: https://drupal.org/node/1096988

Something like this?

Additional programmatic settings

1) Skip domain checks

The Domain Access module does additional checks on the primary domain to prevent users from accidentally misconfiguring this vitally important domain setting. Errors here can render a site inoperable. However, there are some use-cases where you need to bypass this restriction and the internal site variable flag, domain_skip_domain_check allows you to do this. Set this to TRUE to disable domain validation. Once you have saved the domain, reset this to FALSE to re-enable validation. This setting was added in version 7.x-3.????

Yes, plus an example of the change to settings.php

$conf['domain_skip_domain_check'] = TRUE;

It will go in to 7.x.3.4.

Added :)

I encountered the same error when changing a project to a new default domain.
It turned out te be a DNS issue, unrelated to 'domain access', that I worked around by adding the new domain name to the hosts file of the server.

I think these tests are there for a reason and should not be disabled by default.