[GHC] #4332: regression: GHCi command output can no longer be redirected on a by-command basis

[GHC]

#4332: regression: GHCi command output can no longer be redirected on a by-command
basis
---------------------------------+------------------------------------------
    Reporter:  claus             |       Owner:              
        Type:  bug               |      Status:  new         
    Priority:  normal            |   Component:  GHCi        
     Version:  6.12.3            |    Keywords:              
    Testcase:                    |   Blockedby:              
          Os:  Windows           |    Blocking:              
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown
---------------------------------+------------------------------------------
 For writing advanced GHCi scripts, it is very helpful to be able to
 redirect the output of individual GHCi commands, for further processing by
 user-defined GHCi commands.

 This no longer works in GHCi 6.12.3 (probably has stopped working earlier)
 on Windows. Surprisingly, the issue is not consistent - for instance,
 `:type` can still be redirected, `:info` cannot.
 {{{
 ------------- example session output, using attached 'redir.script'
 $ ghcii.sh -ignore-dot-ghci
 GHCi, version 6.12.3: http://www.haskell.org/ghc/  :? for help
 ..
 Prelude> :cmd readFile "redir.script"
 Prelude> :redir x :t map
 ..
 Prelude> x
 "-- logging GHCi stdout\nmap :: (a -> b) -> [a] -> [b]\n"
 Prelude> :redir y :i map
 Prelude> y
 "-- logging GHCi stdout\n*** Exception: WriteConsole: invalid argument
 (Das Handle ist ung\252ltig.)\n"
 ------ (that error message states that the handle is not valid)
 }}}

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-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4332>
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