Description

Remove double encoding of class and style attributes in block supports.

Dynamic blocks rendered by block-supports double encode html which may produce broken results. For example, if we start with valid HTML including a single quote (apostrophe) in a double-quoted attribute, the single quote will be encoded by esc_attr to the unicode HTML entity '. DOMElement::setAttribute will then encode this result to '. This single entity is now doubly encoded and will be interpreted by the browser as '. A full example:

<!-- Saved block content: -->
<div style="background-image:url('https://example.com/image.png');"></div>

<!-- with esc_attr we would get this (also seems to be valid) -->
<div style="background-image:url(&#039;https://example.com/image.png&#039;);"></div>

<!-- setAttribute escapes the escaped attribute, this is now broken -->
<div style="background-image:url(&amp;#039;https://example.com/image.png&amp;#039;);"></div>

When this finally reaches the browser, it makes a request for the background image to the relative path & because the unescaped url is interpreted as 'https://example.com/image.png'.

I've added unit tests which attempt to clarify and verify the expected behavior, we can observe the double encoding in the failed unit tests on the first commit of this PR.

This behavior was introduced in #24486.

How has this been tested?

Unit tests.
Manual testing.

Types of changes

Bug fix: Fix double-encoding of dynamic block classes and styles.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.