Fix Exact Redirect to work properly when using $rest keyword

[humitos]

In #3965 we added the ability to use the full_path but it was added only to the first case and it wasn't considered in the case when $rest keyword was used.

With these changes we can "deprecate a whole sub-path" by writing a Exact Redirect like this:

/en/obsolete-version/$rest ->
/en/newest-version/

and all links pointing to the obsolete-version at any sub-path will be redirected to the newest docs.

Closes #4029
Closes #2444
Closes #3794

[stsewd]

Not sure if this note is necessary, I found it a little confusing, the above example makes more sense for me

[humitos]

I want to have a simple way to explain what Prefix Redirects does because it seems that explaining it by example with a "custom domain" is not enough and confuses people that don't use a custom domain.

So, I'd like to have something very simple explained in one line. Maybe my one-line explanation is not the best and someone can help me here. But I'd like to keep a note like this.

[stsewd]

👍

[stsewd]

Maybe is worth mentioning that is enough to put an absolute url to archive this?

[stsewd]

This useful when renaming dirs too

[humitos]

When renaming dirs the $rest argument shouldn't be used. Instead, you should just use /old-dir/ to /new-dir/. This way, it will do this under all of the languages and versions.

[stsewd]

Same note

[ericholscher]

Looks good. I remember that redirects also have some weird behavior with a leading /, which might be worth investigating here also.

I particularly like the examples. It would probably be useful for us to provide more examples like this, particularly around cases that are common.

[humitos]

I remember that redirects also have some weird behavior with a leading /, which might be worth investigating here also.

Good point!

I just added a test for this to check how it behaves. I'm not sure what's the expected behavior here, but what it does sounds useless to me. Example:

From URL: /jp/latest/$rest
To URL: en/latest/

Hitting /jp/latest/guides/install.html redirects to /jp/latest/guides/en/latest/guides/install.html

What would be good use case for this? Should we validate the presence of the leading / and make it mandatory for Exact Redirects? Is this validation only useful when using $rest in From URL?

[humitos]

I added some test cases and some validation at Form level to avoid people submitting malformed URL (missing leading/trailing slashes).

I suppose this is ready to merge once the tests pass.

A large project related to these changes is to have real redirects, not only on 404: #4550

[ericholscher]

I believe there are other redirects with similar problems. For example:

    @override_settings(USE_SUBDOMAIN=True)
    def test_redirect_page(self):
        Redirect.objects.create(
            project=self.pip, redirect_type='page',
            from_url='install.html', to_url='/tutorial/install.html'
        )
        r = self.client.get('install.html', HTTP_HOST='pip.readthedocs.org')
        self.assertEqual(r.status_code, 302)

This will return False because a path will never not start with a / from Django. So we shouldn't let users save a from_url without a / (or we should add it for them).

[humitos]

Just realized that we do support redirect to external URLs, so we need to support URLs starting with http also. This needs more thinking... As usual :)

I think this is deviating from the original purpose of the PR: fix the exact redirect with the usage of $rest. I want to have this fixed, merged and deployed soon, so I will create an issue to fix other issues around redirects and revert the commit of the validation.

[ericholscher]

Sounds good. 👍

[wohali]

@humitos When will this fix go live? I'm unable to get it working just yet....Thank you so much for your work on this! 🎊

[humitos]

@wohali Hi! We are planning to deploy this tomorrow.

[humitos]

This is already deployed and should be working.