Partial type signatures and generalisation

This should be rejected

foo :: Num a => a -> a
foo x = g x x
 where
   g :: Num b => _ -> b -> b
   g _ y = x + y

But it isn't.

Trac metadata

Trac field	Value
Version	8.2.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture