Editor: Warning when creating new page: "implode(): Invalid arguments"

[aduth]

Previously: ​https://github.com/WordPress/gutenberg/issues/13875

The file edit-form-blocks.php calls implode on the result of a call to wp_set_post_lock. Per the documentation of the function, it can return a value of false which, when passed to implode, could result in a warning.

​https://github.com/WordPress/wordpress-develop/blob/7bdef3d/src/wp-admin/edit-form-blocks.php#L252
​https://developer.wordpress.org/reference/functions/wp_set_post_lock/

While it was not personally reproduced, presumably it could occur under the condition "if the post does not exist, or there is no current user" (from the documentation of wp_set_post_lock).

In any case, given the return type of wp_set_post_lock allowing for a boolean return value, it should not be passed directly into implode without first checking the type returned.

[kakshak]

@aduth I've created the patch for checking the return type of wp_set_post_lock

[SergeyBiryukov]

In 45413:

Editor: In edit-form-blocks.php, check the result of wp_set_post_lock(), which may return false and cause a warning when passed to implode().

Props kakshak, aduth.
Fixes #47013.