[GHC] #13644: overloaded name used in record pattern matching leads to panic! (the 'impossible' happened) in ghc

[GHC]

#13644: overloaded name used in record pattern matching leads to panic!  (the
'impossible' happened) in ghc
-------------------------------------+-------------------------------------
        Reporter:  pjljvdlaar        |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  8.0.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13840, #13973,   |  Differential Rev(s):
  #14087                             |
       Wiki Page:                    |
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Comment (by mpickering):

 Replying to [comment:16 adamgundry]:
 > @simonpj thanks for pointing me to this ticket.
 >
 > > The problem is in TcPat.find_field_ty but I can't see how to cleanly
 fix it.
 >
 > @mpickering part of the fix is surely to compare the selector names
 (which we have available). I've implemented this in
 52110a7966848538583acb65f6e064aadc751260 and it fixes the original test
 case.
 >
 > However, the related bug #13847 remains: this patch is too liberal as it
 accepts examples where the field label is in scope only qualified, but it
 is used unqualified, and `DisambiguateRecordFields` is not enabled.
 Several of the other related bugs demonstrate this, so my patch causes
 them to be accepted (without a panic, but without an error either).
 >
 > I'm out of time to investigate further for now, unfortunately.

 Is it not currently implemented like it is to enabled ORF to work
 properly? I think your patch changes it back to how it used to work? I can
 possibly try to create a test case tomorrow.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13644#comment:18>
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