[GHC] #4411: Incorrect defined but not used warning with record wildcards

[GHC]

#4411: Incorrect defined but not used warning with record wildcards
---------------------------------+------------------------------------------
    Reporter:  NeilMitchell      |       Owner:                                   
        Type:  bug               |      Status:  new                              
    Priority:  normal            |   Component:  Compiler                         
     Version:  6.12.3            |    Keywords:                                   
    Testcase:                    |   Blockedby:                                   
          Os:  Unknown/Multiple  |    Blocking:                                   
Architecture:  Unknown/Multiple  |     Failure:  Incorrect warning at compile-time
---------------------------------+------------------------------------------
 {{{

 {-# LANGUAGE RecordWildCards #-}

 module Test where

 data T = MkT { f,g :: Int }

 p1 x = let MkT{..} = x in f

 p2 MkT{..} = f
 }}}

 With GHC 6.12.3 this gives the warning:

 {{{
 Test.hs:7:11: Warning: Defined but not used: `g'
 }}}

 i.e. {{{p1}}} gives a warning, but {{{p2}}} doesn't. Neither is meant to
 give a warning.

 -- Neil

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4411>
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