[GHC] #4120: Iface type variable out of scope in cast

[GHC]

#4120: Iface type variable out of scope in cast
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  Reporter:  benl                     |          Owner:                  
      Type:  bug                      |         Status:  closed          
  Priority:  high                     |      Milestone:  6.14.1          
 Component:  Compiler (Type checker)  |        Version:  6.13            
Resolution:  fixed                    |       Keywords:                  
Difficulty:                           |             Os:  Unknown/Multiple
  Testcase:                           |   Architecture:  Unknown/Multiple
   Failure:  Runtime performance bug  |  
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Changes (by simonpj):

  * status:  new => closed
  * resolution:  => fixed


Comment:

 Fixed by
 {{{
 Mon Jun 14 14:43:11 BST 2010  simonpj at microsoft.com
   * Fix Trac #4120: generate a proper coercion when unifying forall types

   This was just a blatant omission, which hasn't come up before.
   Easily fixed, happily.

     M ./compiler/typecheck/TcUnify.lhs -3 +8
 }}}
 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4120#comment:2>
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