Use simpler disambiguation criterion in case of double defs

Author: odersky

compiler/src/dotty/tools/dotc/core/Denotations.scala

@@ -449,27 +449,29 @@ object Denotations {
  * - minimizes raising of doubleDef errors
  */
  def preferSym(sym1: Symbol, sym2: Symbol) =
- sym1.eq(sym2) ||
- sym1.exists &&
- (!sym2.exists ||
- sym1.isAsConcrete(sym2) &&
- (!sym2.isAsConcrete(sym1) ||
- precedes(sym1.owner, sym2.owner) ||
- accessBoundary(sym2).isProperlyContainedIn(accessBoundary(sym1)) ||
- sym2.is(Bridge) && !sym1.is(Bridge) ||
- sym1.is(Method) && !sym2.is(Method)) ||
- sym1.info.isErroneous)
+ sym1.eq(sym2)
+ || sym1.exists
+ && (!sym2.exists
+ || sym1.isAsConcrete(sym2)
+ && (!sym2.isAsConcrete(sym1)
+ || precedes(sym1.owner, sym2.owner)
+ || accessBoundary(sym2).isProperlyContainedIn(accessBoundary(sym1))
+ || sym2.is(Bridge) && !sym1.is(Bridge)
+ || sym1.is(Method) && !sym2.is(Method))
+ || sym1.info.isErroneous)
+
+ def preferSymSimple(sym1: Symbol, sym2: Symbol) =
+ sym1.is(Method) && !sym2.is(Method) || sym1.info.isErroneous
 
  /** Sym preference provided types also override */
  def prefer(sym1: Symbol, sym2: Symbol, info1: Type, info2: Type) =
  preferSym(sym1, sym2) &&
  info1.overrides(info2, sym1.matchNullaryLoosely || sym2.matchNullaryLoosely, checkClassInfo = false)
 
  def handleDoubleDef: Denotation =
- if (preferSym(sym1, sym2)) denot1
- else if (preferSym(sym2, sym1)) denot2
- else if sym1.exists then MultiDenotation(denot1, denot2)
- else doubleDefError(denot1, denot2, pre)
+ if preferSymSimple(sym1, sym2) then denot1
+ else if preferSymSimple(sym2, sym1) then denot2
+ else MultiDenotation(denot1, denot2)
 
  if (sym2Accessible && prefer(sym2, sym1, info2, info1)) denot2
  else {