patch applied (cabal-install): Fix constraint set handling for installed constraints

[Duncan Coutts]

Fri Dec 19 10:23:28 PST 2008  Duncan Coutts <duncan at haskell.org>
  * Fix constraint set handling for installed constraints
  A rather subtle bug. The code was actually correct but the transitionsTo
  assertion was not accounting for a transition between the case where
  a package's available version had been excluded and then the whole thing
  got excluded by a version constraint. It counted one side as a loss
  without a corresponding gain on the other side.

    M ./Distribution/Client/Dependency/TopDown/Constraints.hs -2 +5

View patch online:
http://darcs.haskell.org/cabal-install/_darcs/patches/20081219182328-adfee-c89cd874f82a3b444aafe5681960316cbd2a231e.gz