patch applied (cabal-install): Use installed constraints instead of hiding versions of the base package

[Duncan Coutts]

Fri Dec 19 11:37:40 PST 2008  Duncan Coutts <duncan at haskell.org>
  * Use installed constraints instead of hiding versions of the base package
  We want to stop cabal-install from accidentally trying to upgrade
  the base package since this doesn't work in most cases. We used to
  achieve that by deleting the base package from the available package
  index. We now do it by leaving the package index as is and instead
  adding a constraint that we pick only an installed version of base.
  This is a nicer hack and has the potential to give better error
  messages.

    M ./Distribution/Client/Dependency.hs -15 +9

View patch online:
http://darcs.haskell.org/cabal-install/_darcs/patches/20081219193740-adfee-a71408b5482cd9fb58d127ada91cb29b175ec85b.gz