Merge pull request #4388 from retronym/ticket/9223

SI-9223 By-name constructor params should not be aliased

3 files changed, 17 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 3a85d16f55..758425aad5 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -2053,7 +2053,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper
                 case acc                                           => acc
               }
               ownAcc match {
-                case acc: TermSymbol if !acc.isVariable =>
+                case acc: TermSymbol if !acc.isVariable && !isByNameParamType(acc.info) =>
                   debuglog(s"$acc has alias ${alias.fullLocationString}")
                   acc setAlias alias
                 case _ =>
diff --git a/test/files/run/t9223.scala b/test/files/run/t9223.scala
new file mode 100644
index 0000000000..78767b158d
--- /dev/null
+++ b/test/files/run/t9223.scala
@@ -0,0 +1,8 @@
+class X(val x: String)
+class Y(y: => String) extends X(y) { def f = y }
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    assert(new Y("hi").f == "hi")
+  }
+}
diff --git a/test/files/run/t9223b.scala b/test/files/run/t9223b.scala
new file mode 100644
index 0000000000..2afc7ddfe0
--- /dev/null
+++ b/test/files/run/t9223b.scala
@@ -0,0 +1,8 @@
+class X(x: => String) { def xx = x }
+class Y(y: String) extends X(y) { def f = y }
+
+object Test {
+  def main(args: Array[String]): Unit = {
+     assert(new Y("hi").f == "hi")
+  }
+}