[GHC] #10537: Parser: commas_tup_tail returns spurious "Missing" value

[GHC]

#10537: Parser: commas_tup_tail returns spurious "Missing" value
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        Reporter:  alanz             |                   Owner:  alanz
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  7.10.2
       Component:  Compiler          |                 Version:  7.10.1
  (Parser)                           |                Keywords:
      Resolution:                    |            Architecture:
Operating System:  Unknown/Multiple  |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by simonpj):

 It doesn't look duplicated to me. There are indeed two missing elements in
 the tuple.

 Do you have a program that goes wrong?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10537#comment:1>
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