sanitize_post_field() forgets some integer fields

[GeertDD]

The post_author and comment_count properties of the $post object should be sanitized to integer values instead of strings (the default data type).

Both those fields are stored in BIGINT(20) columns in the posts table. They can only contain integer values.

22324.ut.diff​ checks for integer fields after sanitize_post.

In 1193/tests:

sanitize_post() test for integer fields. props kovshenin. see #22324.

In 23353:

Sanitize post_author and comment_count as integer fields. props GeertDD. fixes #22324.

Re-opening for new unit test failures. The following tests need updates if this is correct:

1) Tests_XMLRPC_mw_getPost::test_valid_post
Failed asserting that 286 is of type "string".   

/wordpress-tests/tests/xmlrpc/mw/getPost.php:57

2) Tests_XMLRPC_mw_getRecentPosts::test_valid_post
Failed asserting that 292 is of type "string".   

/wordpress-tests/tests/xmlrpc/mw/getRecentPosts.php:62

3) Tests_XMLRPC_wp_getPage::test_valid_page
Failed asserting that 368 is of type "string".

/wordpress-tests/tests/xmlrpc/wp/getPage.php:56

4) Tests_XMLRPC_wp_getPost::test_valid_post
Failed asserting that 387 is of type "string".

/wordpress-tests/tests/xmlrpc/wp/getPost.php:51

The tests shouldn't be updated. We talking about the XML-RPC here so we probably should update the code then.
I'm looking into it what changed.

Looking into it this never should have been committed as it is. Changing the data type is really dangerous and should be tested well and also the external API's should be checked. This since the app can crash now due their strictness of data types.

Be sure that post_author is a string when calling the XML-RPC

Added the fix for the XML-RPC

22324.fix-xmlrpc.diff​ looks consistent with [19071].

wp.getPage() description in Codex appears to be inaccurate:
​http://codex.wordpress.org/XML-RPC_wp#wp.getPage

It states that userid is an int, whereas it was actually a string. Related: ticket:18869:4.

Updated the Codex page. 22324.fix-xmlrpc.diff​ passes the unit tests.

In 23359:

Cast post_author to string in XML-RPC methods. props markoheijnen. fixes #22324.

I'm not 100% sure this is a good change to make without further review and testing.

One thing that is probably broken by this change is anything that does post author highlighting of comments because get_comments returns straight db data with everything as strings.

We use a value and type === check here - ​https://core.trac.wordpress.org/browser/trunk/wp-includes/comment-template.php#L316

Which now will fail as one will be an int and one a string.

This uncovered a subtle caching bug on wp.com that I think probably affects a lot of plugins, and maybe elsewhere in core. Two cases.

1) Used to work, but with this change started failing.

• Post content is stored in the cache and so post_author is returned as a string when get_post() is called.
• Plugin loads the post_author from cache and then === compares against something like comment_author

2) Failed before (very rare though due to caching, so we had never reproduced it), with this change it works.

• Post content is loaded from db rather than cache by get_post(). post_author is an int.
• Plugin does a === comparison which fails against things like comment_author.

The second example is a bug that is probably occurring now in many plugins, but so rarely that it is not noticed.

Given that (2) is actually failing, maybe the int coming out of the db should actually be cast to a string in get_post(), etc.

This was reverted on wordpress.com for the aforementioned reasons.

Replying to westi:

I'm not 100% sure this is a good change to make without further review and testing.

One thing that is probably broken by this change is anything that does post author highlighting of comments because get_comments returns straight db data with everything as strings.

We use a value and type === check here - ​https://core.trac.wordpress.org/browser/trunk/wp-includes/comment-template.php#L316

Which now will fail as one will be an int and one a string.

This does indeed break post author highlighting. Twenty Twelve is no longer highlighting post author comments because it does an identicality check here: http://core.trac.wordpress.org/browser/tags/3.5.1/wp-content/themes/twentytwelve/functions.php#L291

In 23531:

Revert [23359]. The post_author and comment_count post object fields will remain numeric strings for back compat. see #22324.

In 1224/tests:

Change unit tests to reflect [23531]. see #22324.