HTTP Header typo X-Robots instead of X-Robots-Tag

[michelleblanchette]

Code is here: ​https://github.com/WordPress/wordpress-develop/blob/f4fa4dd1bab07b3b4d90ece4f988d2adcacc4733/src/wp-includes/class-wp-customize-manager.php#L1911C55-L1911C55

It seems X-Robots is not a valid HTTP header. The correct header is X-Robots-Tag.

Looking at the git blame, this was apparently introduced 7 years ago and hasn't been touched since.

Changing the X Robots header to X Robots Tag

Trac ticket: https://core.trac.wordpress.org/ticket/58865

[audrasjb]

Thanks for the ticket and patch!
Self assigning for 6.4 commit consideration.

[rajinsharwar]

The diff of the patch

[audrasjb]

@dhruvishah2203 @rajinsharwar thanks for the patches, but I don't really get the point of copying the pull request that was already sent into a new patch (and especially @rajinsharwar since it was your own PR).

[rajinsharwar]

Hey @audrasjb, I might have been confused, as I saw @dhruvishah2203 attaching a patch file, I also thought that I need to attach that as well. Will take a note from the next.

[jorbin]

While x-robots-tag is the standard, since this has been in place for so long it is possible that someone is using this information in a reverse proxy cache or in some other way. As such, I think the removal of the x-robots header is a bad idea and instead we should simply add the correct header.

[elrae]

Good point @jorbin I added a new patch which just adds the new header rather than replacing it.

Trac ticket:

[adamsilverstein]

In 56462:

Customizer: use the correct X-Robots-Tag header.

Fix an issue where the X-Robots header was used instead of the X-Robots-Tag header. Using X-Robots-Tag yields the correct behavior that the original code intended to add. X-Robots is left in place for backward compatibility.

Props michelleblanchette, dhruvishah2203, rajinsharwar, jorbin, hztyfoon, elrae. 

Fixes #58865.