[GHC] #10320: -ddump-to-file should create empty dump files when there was nothing to dump

[GHC]

#10320: -ddump-to-file should create empty dump files when there was nothing to
dump
-------------------------------------+-------------------------------------
        Reporter:  rwbarton          |                Owner:  tvv
            Type:  bug               |               Status:  patch
        Priority:  low               |            Milestone:
       Component:  Compiler          |              Version:  7.10.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1514
       Wiki Page:                    |
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Comment (by osa1):

 This patch breaks things; try `-ddump-to-file -ddump-simpl`, it's failing
 with:

 {{{
 Main.dump-simpl: hPutStr: illegal operation (handle is closed)
 }}}

 I had to comment out `bracket_`s first argument that closes handles. It
 seems like it's closing handles too soon.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10320#comment:7>
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