FullParameterization: fix rewiring of Returns

Author: smarter

src/dotty/tools/dotc/transform/FullParameterization.scala

@@ -176,7 +176,12 @@ trait FullParameterization {
           } else EmptyTree
         }
         tree match {
-          case Ident(_) => rewireCall(thisRef)
+          case Ident(_) =>
+            val rewired = rewiredTarget(tree, derived)
+            if (rewired.exists) // This only happens when `tree` is the `from` part of a Return
+              Ident(rewired.termRef)
+            else
+              EmptyTree
           case Select(qual, _) => rewireCall(qual)
           case tree @ TypeApply(fn, targs1) =>
             assert(targs.isEmpty)

test/dotc/tests.scala

@@ -68,6 +68,7 @@ class tests extends CompilerTest {
   @Test def pos_t2613 = compileFile(posSpecialDir, "t2613")(allowDeepSubtypes)
   @Test def pos_packageObj = compileFile(posDir, "i0239")
   @Test def pos_anonClassSubtyping = compileFile(posDir, "anonClassSubtyping")
+  @Test def pos_extmethods = compileFile(posDir, "extmethods")
 
   @Test def pos_all = compileFiles(posDir, failedOther)
 

tests/pos/extmethods.scala

@@ -3,4 +3,5 @@ class T[A, This <: That1[A]](val x: Int) extends AnyVal {
   self: This =>
   var next: This = _
   final def loop(x: This, cnt: Int): Int = loop(x, cnt + 1)
+  def const[B](): Boolean = return true
 }