Tinymce wpviews cause a undo loop that inhibits the user from undoing changes

[gcorne]

When a post has one or more wpviews, it is possible to get the editor in a state where previous changes cannot be undone via ctrl+z / command+z.

To reproduce,

1. Create and save a post with at least one gallery and a block of text before and after.
2. Cut some of the text and paste it somewhere.
3. Try to undo twice.

Expected:
The pasted text to be removed and the cut text to be restored.

Actual:
The pasted text is removed, but the cut text is not restored.

This occurs when wp.mce.views.render() is called and updates the DOM. See line 143 in the wpview plugin.

[gcorne]

27516-01.patch​ fixes the issue by not (re-)rendering views when the format of content is raw. If the format is "raw", we can assume that the view has already been incorporated into the DOM.

[wonderboymusic]

In 27544:

MCE Views: don't (re-)render views if the format of the content is "raw" to avoid adding additional undo levels on undo/redo.

Props gcorne.
Fixes #27416.