[GHC] #7099: 'instance Show' results in stack overflow

[GHC]

#7099: 'instance Show' results in stack overflow
---------------------------+------------------------------------------------
 Reporter:  pl             |          Owner:                
     Type:  bug            |         Status:  new           
 Priority:  normal         |      Component:  Compiler      
  Version:  7.4.2          |       Keywords:                
       Os:  Linux          |   Architecture:  x86_64 (amd64)
  Failure:  Runtime crash  |       Testcase:                
Blockedby:                 |       Blocking:                
  Related:                 |  
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 When I load the code below in ghci and run 'create :: C' the execution
 ends after a while with a stack overflow.  However, when I delete the line
 'instance Show C' and erase the '--' before 'deriving (Show)' the command
 'create :: C' delivers a 'C' as I would expect it.

 > module Main where[[BR]]
 >[[BR]]
 > data C = C --deriving (Show)[[BR]]
 >[[BR]]
 > instance Show C[[BR]]
 >[[BR]]
 > class T m where[[BR]]
 >       create :: m [[BR]]
 >
 > instance T C where[[BR]]
 >       create = C[[BR]]

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7099>
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