[GHC] #7787: modifyMVar does not restore value if callback returns error value

[GHC]

#7787: modifyMVar does not restore value if callback returns error value
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        Reporter:  joeyadams                    |            Owner:
            Type:  bug                          |  simonmar
        Priority:  high                         |           Status:  new
       Component:  libraries/base               |        Milestone:  7.8.1
      Resolution:                               |          Version:  7.7
Operating System:  Unknown/Multiple             |         Keywords:
 Type of failure:  Incorrect result at runtime  |     Architecture:
       Test Case:                               |  Unknown/Multiple
        Blocking:                               |       Difficulty:
                                                |  Unknown
                                                |       Blocked By:
                                                |  Related Tickets:
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Comment (by simonmar):

 Fixed:

 commit fd39d598e570145ac144b9cb6512c7faa3092ae1
 {{{
 Author: Simon Marlow <marlowsd at gmail.com>
 Date:   Fri Jul 19 09:09:39 2013 +0100

     Fix #7787

     Now the pair is evaluated strictly inside the exception handler.  I
     figured this would be less likely to introduce space leaky bugs than
     using an irrefutable pattern match.
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7787#comment:6>
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