patch applied (cabal): Change dependency resolution algorithm.

[Duncan Coutts]

Sun Apr 13 06:18:07 PDT 2008  Thomas Schilling <nominolo at gmail.com>
  * Change dependency resolution algorithm.
  
  There were two reasons to do this.  Firstly, this formulation makes it
  easier to add the --constraint command line flag that adds additional
  constraints on the packages that should be used.
  
  Secondly, with the orgininal algorithm it was possible to satisfy the
  constraint "foo < 1, foo > 2" if we had two versions of package "foo"
  which each satisfy one constraint.  This patch fixes this by requiring
  the same package to satisfy both constraints (which of course is
  impossible in this case).

    M ./Distribution/PackageDescription/Configuration.hs -10 +17

View patch online:
http://darcs.haskell.org/cabal/_darcs/patches/20080413131807-75a80-cc4c1b141f6726caefd27689d4fef4de3fb86f2c.gz