[GHC] #10315: ApiAnnotations : Empty context loses annotations

[GHC]

#10315: ApiAnnotations : Empty context loses annotations
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        Reporter:  alanz             |                   Owner:  alanz
            Type:  bug               |                  Status:  closed
        Priority:  normal            |               Milestone:  7.10.2
       Component:  Compiler          |                 Version:  7.10.1
      Resolution:  duplicate         |                Keywords:
Operating System:  Unknown/Multiple  |  ApiAnnotations
 Type of failure:  None/Unknown      |            Architecture:
      Blocked By:                    |  Unknown/Multiple
 Related Tickets:  #10354            |               Test Case:
                                     |                Blocking:
                                     |  Differential Revisions:  Phab:D836
                                     |  Phab:D868
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Comment (by Alan Zimmerman <alan.zimm@…>):

 In [changeset:"0df14b5db06751f817d3ba794cc74ac54519b5b8/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="0df14b5db06751f817d3ba794cc74ac54519b5b8"
 ApiAnnotations : parens around a context with wildcard loses annotations

 Summary:
 In the following code, the extra set of parens around the context end up
 with detached annotations.

     {-# LANGUAGE PartialTypeSignatures #-}
     module ParensAroundContext where

     f :: ((Eq a, _)) => a -> a -> Bool
     f x y = x == y

 Trac ticket #10354

 It turns out it was the TupleTy that was the culprit.

 This may also solve #10315

 Test Plan: ./validate

 Reviewers: hvr, austin, goldfire

 Reviewed By: austin

 Subscribers: goldfire, bgamari, thomie, mpickering

 Differential Revision: https://phabricator.haskell.org/D868

 GHC Trac Issues: #10354, #10315
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10315#comment:8>
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