Normalizing CSS also catches CSS IDs instead of only URLs

[mahype]

The function _wp_normalize_relative_css_links which was introduced in WordPress 5.9.0 does not only preg matching urls, it also matches HTML ids.

The CSS property

clip-path: url(#image1);

will be replaced by

clip-path: url(/relative_url/#image1);

The clip path wont work anymore after this replacement.

[costdev]

Test Report

Env

• Web Server: Apache
• WordPress: 6.0-alpha-52448-src
• Browser: Chrome
• OS: Linux
• Theme: Twenty Twenty-Two
• Plugins: None activated

Steps to test

1. Make the following call:

   echo _wp_normalize_relative_css_links( 'clip-path: url(#image1);', get_stylesheet_uri() );
   

Results

• Expected: clip-path: url(#image1);
• Actual: clip-path: url(/wordpress-develop/src/wp-content/themes/twentytwentytwo/#image1);
• Reproduced ✅ Expected and actual do not match.

Trac ticket: https://core.trac.wordpress.org/ticket/54922

[audrasjb]

Thanks @mahype for reporting this.
The above PR looks good to me.

We should also implement str_starts_with on other places for better consistency in a follow-up 6.0 ticket.

[audrasjb]

I tested the proposed PR and it fixes the issue.

Using:

echo _wp_normalize_relative_css_links( 'clip-path: url(#image1);', get_stylesheet_uri() );

Result before patch:
clip-path: url(/552/wordpress-13/wp-content/themes/twentytwenty/#image1);

Result after patch:
clip-path: url(#image1);

The patch was reviewed by @SergeyBiryukov. It passes the unit tests.
Self assigning for commit.

[audrasjb]

In 52695:

Script Loader: Prevent normalizing HTML IDs in _wp_normalize_relative_css_links().

This change fixes an issue where _wp_normalize_relative_css_links() was not only matching urls, but also HTML IDs.

Follow-up to [52036].

Props mahype, costdev, audrasjb, SergeyBiryukov.
Fixes #54922.

[audrasjb]

Reopening for backport consideration.

Committed in https://core.trac.wordpress.org/changeset/52695

[audrasjb]

In 52714:

Script Loader: Prevent normalizing HTML IDs in _wp_normalize_relative_css_links().

This change fixes an issue where _wp_normalize_relative_css_links() was not only matching urls, but also HTML IDs.

Follow-up to [52036].

Props mahype, costdev, audrasjb, SergeyBiryukov.
Merges [52695] to the 5.9 branch.
Fixes #54922.

[audrasjb]

In 52715:

Script Loader: Prevent normalizing HTML IDs in _wp_normalize_relative_css_links().

This change fixes an issue where _wp_normalize_relative_css_links() was not only matching urls, but also HTML IDs.

Follow-up to [52036].

Props mahype, costdev, audrasjb, SergeyBiryukov.
Merges [52695] to the 5.9 branch.
Fixes #54922.