Fix #9757: Add regression test

OlivierBlanvillain · OlivierBlanvillain · commit b061a4450b25 · 2021-05-27T17:44:42.000+02:00
diff --git a/compiler/test/dotc/pos-test-pickling.blacklist b/compiler/test/dotc/pos-test-pickling.blacklist
@@ -32,6 +32,7 @@ i11250
 i9999.scala
 8649.scala
 12093.scala
+9757.scala
 
 # Opaque type
 i5720.scala
diff --git a/tests/pos/9757.scala b/tests/pos/9757.scala
@@ -0,0 +1,11 @@
+type RemoveFrom[R, A] = R match {
+  case A & newType => newType
+}
+
+def removeOnePart[R, PartR, A](f: R => A, partR: PartR): RemoveFrom[R, PartR] => A = ???
+
+trait A {}
+trait B {}
+
+val f: (A & B) => Int = ???
+val f2 = removeOnePart(f, new A {})
