Add FurtureDefsOK for isBottomType

Triggered by change in TypeComparer. I guess we should think of
dropping the NotDefiendHere tests, for a long time they gave us only false
negatives.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/dotty/tools/dotc/core/Definitions.scala b/src/dotty/tools/dotc/core/Definitions.scala
index 9128bd3a5..7f59cbed0 100644
--- a/src/dotty/tools/dotc/core/Definitions.scala
+++ b/src/dotty/tools/dotc/core/Definitions.scala
@@ -605,7 +605,13 @@ class Definitions {
   }
 
   def isBottomClass(cls: Symbol) = cls == NothingClass || cls == NullClass
-  def isBottomType(tp: Type) = tp.derivesFrom(NothingClass) || tp.derivesFrom(NullClass)
+  def isBottomType(tp: Type) = {
+    def test(implicit ctx: Context) = tp.derivesFrom(NothingClass) || tp.derivesFrom(NullClass)
+    try test
+    catch { // See remark in SymDenotations#accessWithin
+      case ex: NotDefinedHere => test(ctx.addMode(Mode.FutureDefsOK))
+    }
+  }
 
   def isFunctionClass(cls: Symbol) = isVarArityClass(cls, tpnme.Function)
   def isAbstractFunctionClass(cls: Symbol) = isVarArityClass(cls, tpnme.AbstractFunction)