On Saturday 28 May 2011, 12:59:58, I wrote:
Discussion period: two weeks, until 11. June 2011. An old and reopened ticket is at: http://hackage.haskell.org/trac/ghc/ticket/3304
The Proposal:
I would like to propose the elimination of the special error case
gcd 0 0 = error "Prelude.gcd: gcd 0 0 is undefined"
to replace it with
gcd 0 0 = 0
(which would be an automatic consequence of removing the above line).
The discussion period is over, nobody objected. The proposal was supported by Jacques Carette, Cale Gibbard, Sebastian Fischer, Wren Ng Thornton, Ross Paterson, Edward Kmett, Yitzchak Gale (and various others on previous occasions). There was some discussion about the formulation of the documentation, I hope the variant in the patch (based on Ross Paterson's suggestion) is sufficiently clear.