Fix constraint handling in eitherIsSubtype

The logic in typeComparer#eitherIsSubtype was flawed. In the case of A & B <: C, if A <: C but not B <: C we need to return with the constraint of A <: C, but we returned with the initial constraint instead.
tigerqiu712 · Apr 21, 2016 · 3c38a6b · 3c38a6b
1 parent 2460f96
commit 3c38a6b
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/dotty/tools/dotc/core/TypeComparer.scala b/src/dotty/tools/dotc/core/TypeComparer.scala
@@ -678,7 +678,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling {
     isSubType(tp11, tp21) && {
       val leftConstraint = constraint
       constraint = preConstraint
-      if (isSubType(tp12, tp22) && !subsumes(leftConstraint, constraint, preConstraint))
+      if (!(isSubType(tp12, tp22) && subsumes(leftConstraint, constraint, preConstraint)))
         constraint = leftConstraint
       true
     } || isSubType(tp12, tp22)