A test case for overloading/overriding interactions

This showcases a tricky interaction between overloading and overriding.
See discussion of #1240 for context.

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/run/i1240.scala b/tests/run/i1240.scala
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+// A tricky case of overriding behavior
+// Note: It would be acceptable if this produced an error instead.
+// Bit testing this is tricky.
+abstract class Base[T] {
+    def foo(x: T): String
+}
+
+class C[T] extends Base[T] {
+
+    def foo(x: D): String = "D foo"
+    def foo(x: T): String = "T foo"
+}
+
+object Test {
+  def main(args: Array[String]) = {
+    val b1: Base[D] = new C[D] // which of the two foo's in C overrides the one in B?
+    assert(b1.foo(new D) == "T foo")
+    val b2: Base[D] = new C[D] {}
+      // In Java, this gives an error like this:
+      // methods foo(A) from C[D] and foo(String) from C[D] are inherited with the same signature
+      // But the analogous example with `b1` compiles OK in Java.
+    assert(b2.foo(new D) == "T foo")
+  }
+}
+
+class D
+