[GHC] #15572: TH improperly converts promoted data cons in ConT

[GHC]

#15572: TH improperly converts promoted data cons in ConT
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Template Haskell  |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5112
       Wiki Page:                    |
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Comment (by Krzysztof Gogolewski <krz.gogolewski@…>):

 In [changeset:"c46a5f2002f6694ea58f79f505d57f3b7bd450e7/ghc"
 c46a5f20/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="c46a5f2002f6694ea58f79f505d57f3b7bd450e7"
 Fix #15572 by checking for promoted names in ConT

 Summary:
 When converting `ConT`s to `HsTyVar`s in `Convert`, we were
 failing to account for the possibility of promoted data constructor
 names appearing in a `ConT`, which could result in improper
 pretty-printing results (as observed in #15572). The fix is
 straightforward: use `Promoted` instead of `NotPromoted` when the
 name of a `ConT` is a data constructor name.

 Test Plan: make test TEST=T15572

 Reviewers: goldfire, bgamari, simonpj, monoidal

 Reviewed By: goldfire, simonpj

 Subscribers: monoidal, rwbarton, carter

 GHC Trac Issues: #15572

 Differential Revision: https://phabricator.haskell.org/D5112
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15572#comment:2>
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