wp_die stylesheet path needs to be absolute

[filosofo]

I have a plugin that calls wp_die, but not in the WP top-level directory, so the relative links to the error message stylesheet don't work.

The attached patch makes the path to the stylesheet absolute.

[Sewar]

This way wp_die won't work if WP didn't installed yet, see #3138.

But if #4003 committed, this will be usable.

[filosofo]

Replying to Sewar:

This way wp_die won't work if WP didn't installed yet, see #3138.

Oops. I wondered why that existing code was there.

The second patch works even without wp installed, in the top-level directory and in wp-admin.

I also added a fix you can see in the upper half of the patch for a problematic call to is_wp_error if you try to run /wp-admin/install.php

[Sewar]

Great, if this code moved to get_bloginfo('wpurl') it will be possible for other parts of WP to use it also.

Thanks a lot for fixing these bugs.

[Nazgul]

New patch which tries multiple ways of determining the admin_dir if the previous one fails.

[markjaquith]

(In [6057]) Try more ways of getting wp-admin URL in wp_die(). props Nazgul. fixes #4006