FIX for "mb_detect_encoding() expects parameter 1 to be string, resource given"

[spidgorny]

When one of the debug arrays contains a resource, is_resource() function sometimes does not detect it well. See http://php.net/manual/en/function.is-resource.php#103942 for details. This is the fix for the situation.

[cadorn]

You need to send a diff against latest master. This PR has many old changes in it that are already on master.