Cloning broken

Hi,

on latest version key_value field shows empty in post editing, even though it has values saved in database. It also saves values, but when returning back to the post edit screen the fields are empty. So the rendering is broken.

Looking the code, this seems to be due to $meta array structure the code loops in RWMB_Clone::html() does not work properly due to additional entry on $meta, which makes the $meta array incompatible with the code in foreach loop that is supposed to output the field. The empty entry seems to be added to $meta in RWMB_Field::meta() method, and there is comment with it:

// Always add the first item to the beginning of the array for the template.
// We will need to remove it later before saving.
array_unshift( $meta, $field['std'] );

This code is not on the previous metabox version that still works, 5.9.10.

I think this would add all cloneable fields and saw several bug reports on the forum from recent days.

Revert back to metabox version 5.9.10 until this is fixed.

If you edited a post with cloneable field it's values got rewritten into database, likely with empty array if you didn't specifically edit the cloneable field but something else and didn't notice the cloneable field was empty while saving the post.

Please fix this, thanks!