Merge pull request #1711 from dotty-staging/fix-isNullable

odersky · web-flow · commit 6f04ca7f4972 · 2016-11-17T11:22:08.000+01:00
Fix isNullable when `&lt;:&lt;` term refs.
diff --git a/src/dotty/tools/dotc/core/TypeComparer.scala b/src/dotty/tools/dotc/core/TypeComparer.scala
@@ -527,7 +527,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling {
           }
           isSubType(hi1, tp2) || compareGADT
         case _ =>
-          def isNullable(tp: Type): Boolean = tp.dealias match {
+          def isNullable(tp: Type): Boolean = tp.widenDealias match {
             case tp: TypeRef => tp.symbol.isNullableClass
             case tp: RefinedOrRecType => isNullable(tp.parent)
             case AndType(tp1, tp2) => isNullable(tp1) && isNullable(tp2)

Original file line number	Diff line number	Diff line change
`@@ -527,7 +527,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling {`
`527`	`527`	`}`
`528`	`528`	`isSubType(hi1, tp2) \|\| compareGADT`
`529`	`529`	`case _ =>`
`530`		`- def isNullable(tp: Type): Boolean = tp.dealias match {`
	`530`	`+ def isNullable(tp: Type): Boolean = tp.widenDealias match {`
`531`	`531`	`case tp: TypeRef => tp.symbol.isNullableClass`
`532`	`532`	`case tp: RefinedOrRecType => isNullable(tp.parent)`
`533`	`533`	`case AndType(tp1, tp2) => isNullable(tp1) && isNullable(tp2)`