2 files changed, 57 insertions, 0 deletions
diff --git a/test/files/neg/no-implicit-to-anyref.check b/test/files/neg/no-implicit-to-anyref.check
new file mode 100644
index 0000000000..d94b57a30a
--- /dev/null
+++ b/test/files/neg/no-implicit-to-anyref.check
@@ -0,0 +1,28 @@
+no-implicit-to-anyref.scala:11: error: type mismatch;
+ found   : Int(1)
+ required: AnyRef
+Note: an implicit exists from scala.Int => java.lang.Integer, but
+methods inherited from Object are rendered ambiguous.  This is to avoid
+a blanket implicit which would convert any scala.Int to any AnyRef.
+You may wish to use a type ascription: `x: java.lang.Integer`.
+    1: AnyRef
+    ^
+no-implicit-to-anyref.scala:17: error: type mismatch;
+ found   : Any
+ required: AnyRef
+    (null: Any): AnyRef
+         ^
+no-implicit-to-anyref.scala:21: error: type mismatch;
+ found   : AnyVal
+ required: AnyRef
+    (0: AnyVal): AnyRef
+      ^
+no-implicit-to-anyref.scala:27: error: type mismatch;
+ found   : Test.AV
+ required: AnyRef
+Note that AV extends Any, not AnyRef.
+Such types can participate in value classes, but instances
+cannot appear in singleton types or in reference comparisons.
+    new AV(0): AnyRef
+    ^
+four errors found
diff --git a/test/files/neg/no-implicit-to-anyref.scala b/test/files/neg/no-implicit-to-anyref.scala
new file mode 100644
index 0000000000..3e3d373e38
--- /dev/null
+++ b/test/files/neg/no-implicit-to-anyref.scala
@@ -0,0 +1,29 @@
+// Checks that the state of standard implicits in Predef._ and scala._
+// doesn't allow us to unambiguously and implicitly convert AnyVal
+// and subtypes to AnyRef.
+//
+// In the days before value classes, this was precariously held be
+// the competing implicits Any => StringAdd and Any => StringFormat.
+// Since then, these have both become value classes, but seeing as
+// this happened simultaneously, we're still okay.
+object Test {
+  locally {
+    1: AnyRef
+  }
+
+  locally {
+    // before this test case was added and ContextErrors was tweaked, this
+    // emitted: "Note that Any extends Any, not AnyRef."
+    (null: Any): AnyRef
+  }
+
+  locally {
+    (0: AnyVal): AnyRef
+  }
+
+  class AV(val a: Int) extends AnyVal
+
+  locally {
+    new AV(0): AnyRef
+  }
+}