REST API: Revision author ID is returned as a string

[jnylen0]

Apparently post_author is a string in the WP internals, "for compatibility reasons".

In WP_REST_Posts_Controller we cast it to an integer before returning it in the response.

In WP_REST_Revisions_Controller we don't do the corresponding cast.

The result is that the author ID is returned as a string, even though it is documented as an integer for both posts and revisions.

[jnylen0]

In 40063:

REST API: Cast revision author ID to int.

The post_author field is a string internally, but we need to cast it to an integer in the REST API. This was already done for posts, but not for revisions. The field is already declared as an integer in both controllers.

Fixes #39871.

[jnylen0]

Reopening for backport to 4.7 branch.

[rachelbaker]

In 40078:

REST API: Cast revision author ID to int.

The post_author field is a string internally, but we need to cast it to an integer in the REST API. This was already done for posts, but not for revisions. The field is already declared as an integer in both controllers.

Props jnylen0.
Merges [40063] to the 4.7 branch.
Fixes #39871.