Removing a custom field via XML-RPC results in a PHP Notice

[scott.gonzalez]

In order to remove a custom field, you pass the id without a key or value, but the code is currently checking for a value before determining if the field should be deleted.

PHP Notice: Undefined index: value in .../wp-includes/class-wp-xmlrpc-server.php on line 279

testing against HEAD.

[nacin]

​http://unit-tests.trac.wordpress.org/changeset/697

php wp-test.php -d -t TestXMLRPCServer_wp_editPost (-d forcing WP_DEBUG on) -- before patch, error due to this notice.

[nacin]

In [20583]:

Do not check for a meta value in XML-RPC set_custom_fields unless we know we are editing a key. Prevents a notice when a custom field is being deleted. props scott.gonzalez. fixes #20543.