[GHC] #12780: Calling "do nothing" type checker plugin affects type checking when it shouldn't

[GHC]

#12780: Calling "do nothing" type checker plugin affects type checking when it
shouldn't
-------------------------------------+-------------------------------------
        Reporter:  clinton           |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by clinton):

 * version:  8.0.1 => 8.1


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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12780#comment:1>
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