Fix overriding a Java method with varargs

If A method like:
  override def foo(x: Object*)
overrides a Java method, it needs to be rewritten as:
  def foo(x: Seq[Object])
  override def foo(x: Array[Object]): Object = foo(Predef.wrapRefArray(x))

This should be handled by ElimRepeated but there were two bugs:
- `addVarArgsBridge` was called at phase `thisTransformer.next`, this is
too late to create the bridge since `T*` has already been rewritten as
`Seq[T]`
- The original method symbol needs to have the `override` flag dropped,
since it doesn't override anything.

Furthermore, RefChecks had to be moved after ElimRepeated, otherwise the
testcase would fail the overriding checks.

1 files changed, 3 insertions, 0 deletions

diff --git a/compiler/src/dotty/tools/dotc/typer/RefChecks.scala b/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
index 23d05e087..e8ff7d572 100644
--- a/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
+++ b/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
@@ -766,6 +766,9 @@ class RefChecks extends MiniPhase { thisTransformer =>
 
   override def phaseName: String = "refchecks"
 
+  // Needs to run after ElimRepeated for override checks involving varargs methods
+  override def runsAfter = Set(classOf[ElimRepeated])
+
   val treeTransform = new Transform(NoLevelInfo)
 
   class Transform(currentLevel: RefChecks.OptLevelInfo = RefChecks.NoLevelInfo) extends TreeTransform {