HTML Tag Processor: Add bookmark invalidation logic

[Bernhard Reiter]

While WP_HTML_Tag_Processor currently only supports changing a given tag's attributes, we plan to also provide methods to make broader changes (possibly through a subclass of WP_HTML_Tag_Processor).

An API like that will have the potential of replacing a tag that a bookmark points to. As a preparation, we thus need to make sure that all bookmarks affected by a HTML replacement are invalidated (i.e. released).

While WP_HTML_Tag_Processor currently only supports changing a given tag's attributes, we plan to also provide methods to make broader changes (possibly through a subclass of WP_HTML_Tag_Processor).
An API like that will have the potential of replacing a tag that a bookmark points to. As a preparation, we thus need to make sure that all bookmarks affected by a HTML replacement are invalidated (i.e. released).

This is done by extending the existing loop in apply_attributes_updates that adjusts bookmarks' start and end positions upon HTML changes to check if the entire bookmark is within a portion of the HTML that has been replaced.

Note that this PR is a backport of ​https://github.com/WordPress/gutenberg/pull/47559.

Trac ticket: https://core.trac.wordpress.org/ticket/57788

cc/ @dmsnell 😊

[hellofromTonya]

Original Gutenberg PR ​https://github.com/WordPress/gutenberg/pull/47559.

Thank you! 😊

Just noting that we can't merge this to trunk until Core is comes out of the 6.2 Beta phase, which ​should happen on March 7.

[hellofromTonya]

Patch:

• Confirmed this is a copy of ​Gutenberg PR 47559 ✅
• Includes ticket annotation in tests ✅
• Includes @since annotation ✅
• Change was released in ​Gutenberg 15.3.0 ✅

Ready for commit 👍 Prepping commit now.

Prepping commit now ✅

[hellofromTonya]

In 55555:

HTML API: Add bookmark invalidation logic.

While WP_HTML_Tag_Processor currently only supports changing a given tag's attributes, the plan is to provide methods to make broader changes (possibly through a subclass of WP_HTML_Tag_Processor). The API will have the potential of replacing a tag that a bookmark points to. To prepare, this changeset makes sure that all bookmarks affected by a HTML replacement are invalidated (i.e. released).

Changes:

• Extends the existing loop in WP_HTML_Tag_Processor::apply_attributes_updates() that adjusts bookmarks' start and end positions upon HTML changes to check if the entire bookmark is within a portion of the HTML that has been replaced.
• Adds `WP_HTML_Tag_Processor::has_bookmark() to check whether the given bookmark name exists.

References:

• ​Gutenberg PR 47559
• ​Released in Gutenberg 15.3.0

Follow-up to [55203].

Props bernhard-reiter, dmsnell, zieladam.
Fixes #57788.

Committed via https://core.trac.wordpress.org/changeset/55555.

Thank you very much for landing this @hellofromtonya !