[Hackage] #613: Update .cabal/config along with cabal-install

[Hackage]

#613: Update .cabal/config along with cabal-install
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  Reporter:  guest               |        Owner:      
      Type:  enhancement         |       Status:  new 
  Priority:  low                 |    Milestone:      
 Component:  cabal-install tool  |      Version:  HEAD
  Severity:  minor               |     Keywords:      
Difficulty:  unknown             |   Ghcversion:      
  Platform:                      |  
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 When cabal-install is upgraded, it sometimes gains new features with
 corresponding lines in the default .cabal/config; however, the existing
 .cabal/config is not updated.

 One way of updating it would be to make it, at every invocation of cabal-
 install, rewrite the file using a merger of the current configuration and
 the default one.

 There are some issues with this - most particularily, user-written
 comments in the file should be preserved, without this stopping cabal-
 install from inserting its own comments for (disabled) new features, or
 causing duplication of comments.

 None of this is particularily hard to imagine a solution for, but in the
 interests of avoiding priming, I won't write down my own suggested
 solutions here. If whoever eventually decides to try fixing this explains
 his proposed solution here, I'll chime in then.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/613>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects