Issue #6104 has been reported by Patrick Bennett.

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Bug #6104: File.join always returns as ASCII-8BIT regardless of input encoding
https://bugs.ruby-lang.org/issues/6104

Author: Patrick Bennett
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 1.9.3
ruby -v: ruby 1.9.3p125 (2012-02-16) [i386-mingw32]


I can show lots of different variations, but the simplest proof is:
irb(main):001:0> File.join('foo'.encode('utf-8')).encoding
=> #<Encoding:ASCII-8BIT>



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