- Skips validation where there is no attribute definition, but keeps the attribute value. Previously, the attribute would be omitted from the attributes passed to `render_callback`. Notably, this resolves an issue where `render_callback` cannot receive a block's `align` and `customClassName` attribute values, since these are defined as a client-side filter.
- Validates `null` as a proper value in its own right. Previously, a client implementation of a block could track `{“attribute":null}` as an explicitly empty value, and the server would wrongly initiate defaulting behavior. The new behavior will now only populate a default value if the attribute is not defined at all, including when unset in its being invalid per the attribute schema.
Props aduth, noisysocks, youknowriad, danielbachhuber.
Merges [43918] to trunk.
See #45145 for the patch, #45098 for the original ticket.
git-svn-id: https://develop.svn.wordpress.org/trunk@44269 602fd350-edb4-49c9-b593-d223f7449a82
2ae5bb324d