[GHC] #12513: Template Haskell boxes singleton unboxed tuples when splicing them

[GHC]

#12513: Template Haskell boxes singleton unboxed tuples when splicing them
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        Reporter:  RyanGlScott       |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.0.2
       Component:  Template Haskell  |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC accepts       |  Unknown/Multiple
  invalid program                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #5332             |  Differential Rev(s):  Phab:D2462
       Wiki Page:                    |
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Comment (by Ryan Scott <ryan.gl.scott@…>):

 In [changeset:"fb0d87f1c4a35fa2aaf7f6dd55edbc71c7c3b44d/ghc"
 fb0d87f1/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="fb0d87f1c4a35fa2aaf7f6dd55edbc71c7c3b44d"
 Splice singleton unboxed tuples correctly with Template Haskell

 Summary:
 Previously, TH would implicitly remove the parentheses when splicing in
 singleton unboxed tuple types (e.g., turning `(# Int #)` into `Int`).
 Luckily,
 the fix is simply to delete some code.

 Fixes #12513.

 Test Plan: make test TEST=T12513

 Reviewers: hvr, bgamari, austin, goldfire

 Reviewed By: goldfire

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D2462

 GHC Trac Issues: #12513
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12513#comment:2>
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