[GHC] #5512: UTF-16//ROUNDTRIP encoding behaves weirdly

[GHC]

#5512: UTF-16//ROUNDTRIP encoding behaves weirdly
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    Reporter:  batterseapower    |        Owner:                             
        Type:  bug               |       Status:  new                        
    Priority:  normal            |    Milestone:  7.4.1                      
   Component:  libraries/base    |      Version:  7.2.1                      
    Keywords:                    |     Testcase:                             
   Blockedby:                    |   Difficulty:                             
          Os:  Unknown/Multiple  |     Blocking:                             
Architecture:  Unknown/Multiple  |      Failure:  Incorrect result at runtime
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Comment(by batterseapower):

 You are seeing exactly the expected output. My recent change to have
 mkTextEncoding try our Haskell TextEncodings before it falls back to iconv
 may have made this better.

 In practice, we don't really care whether UTF-16//ROUNDTRIP works because
 we only use //ROUNDTRIP for the fileSystemEncoding (a modified
 localeEncoding), UTF-16 is not an ASCII superset, and IIRC the Posix
 standard requires the locale encoding to be an ASCII superset.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5512#comment:3>
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