[GHC] #11371: Bogus in-scope set in substitutions

[GHC]

#11371: Bogus in-scope set in substitutions
-------------------------------------+-------------------------------------
        Reporter:  simonpj           |                Owner:  niteria
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11360            |  Differential Rev(s):  phab:D1792,
       Wiki Page:                    |  phab:D1801, phab:D1802
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Comment (by Bartosz Nitka <niteria@…>):

 In [changeset:"144ddb414a8a4f40df1ad9ab27fcdf38f30db4d3/ghc"
 144ddb41/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="144ddb414a8a4f40df1ad9ab27fcdf38f30db4d3"
 Construct in_scope set in mkTopTCvSubst

 The pre-condition on `mkTopTCvSubst` turned out to be wrong and
 not satisfied by any of the callers. I've fixed it, so that it
 constructs the in_scope set from the range of the substitution.
 `mkTopTCvSubst` was also unnecessarily general it is never called
 with `CoVars`, so I changed the type signature and added an assertion.

 Test Plan: ./validate --slow

 Reviewers: goldfire, simonpj, bgamari, austin

 Reviewed By: simonpj

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D1801

 GHC Trac Issues: #11371
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11371#comment:14>
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