[GHC] #8827: Inferring Safe mode with GeneralizedNewtypeDeriving is wrong

[GHC]

#8827: Inferring Safe mode with GeneralizedNewtypeDeriving is wrong
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        Reporter:  goldfire          |            Owner:
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:  7.8.1
       Component:  Compiler          |          Version:  7.8.1-rc2
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by Richard Eisenberg <eir@…>):

 In [changeset:"59722295bb8da8f01d37356fbed6aef7321a8195/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="59722295bb8da8f01d37356fbed6aef7321a8195"
 Remove "Safe mode" check for Coercible instances

 We assume that library authors supply correct role annotations
 for their types, and therefore we do not need to check for
 the availability of data constructors in Safe mode. See
 discussion in #8725. This effectively fixes #8827 and #8826.
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8827#comment:9>
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