Canonical redirects disallow tag named comments

[dwc]

The redirect_canonical function includes a regular expression replacement which effectively disallows tags named "comments" to have an RSS feed:

​https://github.com/WordPress/WordPress/blob/master/wp-includes/canonical.php#L285

For example:

/blog1/tag/comments/feed/

This is redirected to:

/blog1/tag/feed/

Could / should the regular expression on line 285 could pay attention to the first placeholder it matched (comments/?) or check whether the page is a tag request?

[asalce]

@dwc I attached a patch which should work. The safest way was to check against the generated site-wide comments feed. Could you take look and let me know if that solves your issue?

[asalce]

@dd32 @markjaquith I looked a bit at the source code and this seems like it has been around for a while. Sorry to pull you in on this one, not sure who would be assigned :)

Here is the commit on Git:
​https://github.com/WordPress/WordPress/commit/ecffc4649f4cb90b43fe0b38ab0f4b18967cb3fd

I was able to reproduce the bug myself, real easy to do so. Just create a tag named "comments" and then try to load the rss feed for the tag: ​http://URL/tag/comments/feed/

Edit: tagged the canonical gods

[dwc]

@asalce Thanks for the patch! I've confirmed it works in my setup.

[asalce]

@swissspidy I submitted the unit-test, The best way I could test this out was to test if the query vars were set correctly after a go_to("/tag/comments/feed/") the query vars should have a "feed" and "tag" should equal "comments" , I also added some other tests to make sure tests were running correctly.

@dwc perfect! :)

[asalce]

Replying to SergeyBiryukov:

I ran into this bug with another site, Any chance this could be moved into 4.7.x ?

[javix]

I have tested this patch successfully, it works for me.

[asalce]

Can this one also be put up for review?
​https://make.wordpress.org/core/2019/02/20/reverting-the-bulk-ticket-closing/ @obenland @JeffPaul

[JeffPaul]

@asalce I don't think this ticket relates to the bulk ticket closing, but if you're asking about getting this milestoned then your best bet is to check with the Canonical component maintainers (see ​https://make.wordpress.org/core/components/permalinks/canonical/).

[asalce]

@JeffPaul Thanks!

@markjaquith this ticket has been in my account for a bit. I supplied a patch and unit testing awhile ago. Let me know what else is needed to get this into a release. Thanks!

• Alberto S.