Patchwork's stream wrapper fails to respect other stream wrappers

[antecedent]

As of now, it simply overrides them. In practice, this problem has recently surfaced with infection/infection (issue).

The behavior should be changed to keep any other stream wrappers in effect.

It turns out that the return value of stream_get_meta_data() contains the stream wrapper object that is currently operating. Preliminarily, this might be helpful.