Merge pull request #7391 from dotty-staging/fix-#7387

odersky · web-flow · commit 705f30499c8a · 2019-10-12T11:06:22.000+02:00
Fix #7387: Avoid comparing NoType with other types
diff --git a/compiler/src/dotty/tools/dotc/core/TypeComparer.scala b/compiler/src/dotty/tools/dotc/core/TypeComparer.scala
@@ -550,6 +550,7 @@ class TypeComparer(initctx: Context) extends ConstraintHandling[AbsentContext] w
           case tp1: RecType =>
             val rthis1 = tp1.recThis
             recur(tp1.parent, tp2.parent.substRecThis(tp2, rthis1))
+          case NoType => false
           case _ =>
             val tp1stable = ensureStableSingleton(tp1)
             recur(fixRecs(tp1stable, tp1stable.widenExpr), tp2.parent.substRecThis(tp2, tp1stable))
diff --git a/tests/neg/i7387.scala b/tests/neg/i7387.scala
@@ -0,0 +1,2 @@
+type E = A.B { type C = D } // error: Not found: A
+def g = summon[E] // error: no implicit argument of type E

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+type E = A.B { type C = D } // error: Not found: A`
	`2`	`+def g = summon[E] // error: no implicit argument of type E`