[GHC] #8495: Infinite loop when using Data.HashTable.newHint and Data.HashTable.update

[GHC]

#8495: Infinite loop when using Data.HashTable.newHint and Data.HashTable.update
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       Reporter:  erszcz            |             Owner:
           Type:  bug               |            Status:  new
       Priority:  normal            |         Milestone:
      Component:  libraries/base    |           Version:  7.4.2
       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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 When using Data.!HashTable.newHint and Data.!HashTable.update to read a
 big (~1.5mln words) file into a !HashTable the program seems to fall into
 an infinite loop.

 "Seems to" since I couldn't wait long enough for it to finish computation.
 At least the execution time is way bigger than expected (orders of
 magnitude, like hours vs. expected seconds).

 Data.!HashTable.new doesn't cause the same issue.

 Attached to the report is an example program reproducing the bug along
 with a data file the issue occurs with.

 The bug was discussed on haskell-beginners mailing list quite a while ago,
 though I've summarized the findings in this bug report. See:
 - http://article.gmane.org/gmane.comp.lang.haskell.beginners/9811
 - http://article.gmane.org/gmane.comp.lang.haskell.beginners/9828

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8495>
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