From 7983a2f17a271d472c172e4a3b30d61e606134a9 Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Wed, 29 Sep 2021 22:21:39 +0200
Subject: [PATCH 1/2] Fix variable handling in super calls

Accesses to var parameters in super calls need to refer to the constructor
parameter, not the getter.

Fixes #13630
---
 .../src/dotty/tools/dotc/transform/Constructors.scala    | 9 ++++++++-
 tests/run/i13630.check                                   | 1 +
 tests/run/i13630.scala                                   | 9 +++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 tests/run/i13630.check
 create mode 100644 tests/run/i13630.scala

diff --git a/compiler/src/dotty/tools/dotc/transform/Constructors.scala b/compiler/src/dotty/tools/dotc/transform/Constructors.scala
index 024261746265..b5b8ae7cd3e4 100644
--- a/compiler/src/dotty/tools/dotc/transform/Constructors.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Constructors.scala
@@ -146,10 +146,16 @@ class Constructors extends MiniPhase with IdentityDenotTransformer { thisPhase =
     //  (2) If the parameter accessor reference was to an alias getter,
     //      drop the () when replacing by the parameter.
     object intoConstr extends TreeMap {
+      private var isSuperCall = false
       override def transform(tree: Tree)(using Context): Tree = tree match {
         case Ident(_) | Select(This(_), _) =>
           var sym = tree.symbol
-          if (sym.is(ParamAccessor, butNot = Mutable)) sym = sym.subst(accessors, paramSyms)
+          if sym.is(ParamAccessor) && (!sym.is(Mutable) || isSuperCall)
+            // Variables need to go through the getter since they might have been updated,
+            // except if we are in a super call, since then the virtual getter call would
+            // be illegal.
+          then
+            sym = sym.subst(accessors, paramSyms)
           if (sym.maybeOwner.isConstructor) ref(sym).withSpan(tree.span) else tree
         case Apply(fn, Nil) =>
           val fn1 = transform(fn)
@@ -161,6 +167,7 @@ class Constructors extends MiniPhase with IdentityDenotTransformer { thisPhase =
       }
 
       def apply(tree: Tree, prevOwner: Symbol)(using Context): Tree =
+        isSuperCall = isSuperConstrCall(tree)
         transform(tree).changeOwnerAfter(prevOwner, constr.symbol, thisPhase)
     }
 
diff --git a/tests/run/i13630.check b/tests/run/i13630.check
new file mode 100644
index 000000000000..64bf9740e617
--- /dev/null
+++ b/tests/run/i13630.check
@@ -0,0 +1 @@
+it worked
diff --git a/tests/run/i13630.scala b/tests/run/i13630.scala
new file mode 100644
index 000000000000..64f260262a8e
--- /dev/null
+++ b/tests/run/i13630.scala
@@ -0,0 +1,9 @@
+class ClassWithLambda(sup: () => Long)
+class ClassWithVar(var msg: String) extends ClassWithLambda(() => 1)
+
+object Test:
+  val _ = new ClassWithVar("foo")
+
+  def main(args: Array[String]): Unit = {
+    println("it worked")
+  }
\ No newline at end of file

From 0210ad8553763741631d3805f788a5e169f5a5cb Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Wed, 29 Sep 2021 23:14:50 +0200
Subject: [PATCH 2/2] Reclassify test

---
 tests/neg/i11045.scala | 5 -----
 tests/run/i11045.scala | 5 +++++
 2 files changed, 5 insertions(+), 5 deletions(-)
 delete mode 100644 tests/neg/i11045.scala
 create mode 100644 tests/run/i11045.scala

diff --git a/tests/neg/i11045.scala b/tests/neg/i11045.scala
deleted file mode 100644
index 1288d7ebb42a..000000000000
--- a/tests/neg/i11045.scala
+++ /dev/null
@@ -1,5 +0,0 @@
-abstract class Foo(x: Any)
-class Boom(var x: Unit, y: Unit) extends Foo((x: Int) => x) // error: super constructor cannot be passed a self reference
-@main def Test =
-  Boom((), ())
-
diff --git a/tests/run/i11045.scala b/tests/run/i11045.scala
new file mode 100644
index 000000000000..2885c7608e60
--- /dev/null
+++ b/tests/run/i11045.scala
@@ -0,0 +1,5 @@
+abstract class Foo(x: Any)
+class Boom(var x: Unit, y: Unit) extends Foo((x: Int) => x) // was error: super constructor cannot be passed a self reference
+@main def Test =
+  Boom((), ())
+