Fix for one of the oldest open soundness bugs.

Closes SI-963, since it was one of my random 30 it won the prize.
The trick after adding the stability check (which has been sitting
there commented out for 3+ years) was that implicit search depended
on the wrongness, because memberWildcardType would create scopes
with members of the form

  ?{ val name: tp }

And since a def shouldn't match that, fixing it broke everything
until I flipped it around: memberWildcardType should be seeking

  ?{ def name: tp }

It could also search for a mutable value: the relevant quality
is that it not be stable so it doesn't have a tighter type than
the members it hopes to match.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
index 0d7ef71193..787d7af136 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
@@ -214,13 +214,13 @@ trait Implicits {
     override def hashCode = 1
   }
 
-  /** A constructor for types ?{ name: tp }, used in infer view to member
+  /** A constructor for types ?{ def/type name: tp }, used in infer view to member
    *  searches.
    */
   def memberWildcardType(name: Name, tp: Type) = {
     val result = refinedType(List(WildcardType), NoSymbol)
     name match {
-      case x: TermName => result.typeSymbol.newValue(x) setInfoAndEnter tp
+      case x: TermName => result.typeSymbol.newMethod(x) setInfoAndEnter tp
       case x: TypeName => result.typeSymbol.newAbstractType(x) setInfoAndEnter tp
     }
     result