Mixed case URLs in the theme directory break the display

[jonoaldersonwp]

See, e.g., ​https://wordpress.org/themes/twentyninetEEn/ vs ​https://wordpress.org/themes/twentynineteen/.

Looks like the JS process (see https://meta.trac.wordpress.org/ticket/4276) isn't handling that well. Hopefully, fixing #4276 resolves this.

Regardless, I'd like us to 301 redirect the mixed/uppercase version to the lowercase version. To contain the complexity of that, I'd be happy for it to just run on ^/themes/{{path}}/$.

[dd32]

In 8920:

Theme Directory: Add canonical redirects for upper-case requests for Themes or section filters to their lower-case variant. The JS is case-sensitive.

Fixes #4364.

[dd32]

In 8921:

Theme Directory: Tighten a regular expression.

Amends [8920].
See #4364.

[dd32]

In 8934:

Theme Directory: Make the canonical redirects for uppercase urls a little less strict.

This uses path comparisons instead to reduce the complexity.

See #4364.

[dd32]

In 8935:

Theme Directory: Fix a typo that didn't make it to the previous commit.

Ammends [8934].
See #4364.

[dd32]

In 9322:

Theme Directory: Remove the is_search() limiter so /themes/TWentyTWenty/ redirects to /themes/twentytwenty/ yet again.

See #4364.