plack/Plack — pull request #354 by miyagawa (2012-11-27 09:50:46+00:00)
Title: Check if a string contains wide string, by actually printing it to a dummy handle

The Lint's utf-8/wide-strings check currently uses `utf8::is_utf8` *and* whether the string actually contains the hight bit. Based on my experience this should work as expected but it is basically testing what is inside, rather than how it behaves.

This patch makes the check by actually printing to a dummy IO and see if the warning is emitted.