From 103ec8cb5229f1bd6cda68ef4126e4b875895b90 Mon Sep 17 00:00:00 2001
From: Jason Zaugg <jzaugg@gmail.com>
Date: Thu, 7 Feb 2019 15:44:18 +1000
Subject: [PATCH] Fix ownership corruption problem in the awaited expression

Previously, `whyDoYouHateMe` was incorrectly owned by `jerk`,
rather than `pointlessSymbolOwner` after the ANF transform,
which in turn led to:

```
java.util.NoSuchElementException: value whyDoHateMe
    at scala.collection.mutable.AnyRefMap$ExceptionDefault.apply(AnyRefMap.scala:425)
    at scala.collection.mutable.AnyRefMap$ExceptionDefault.apply(AnyRefMap.scala:424)
    at scala.collection.mutable.AnyRefMap.apply(AnyRefMap.scala:180)
    at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder$locals$.load(BCodeSkelBuilder.scala:390)
    at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:354)
```
---
 .../scala/async/internal/AnfTransform.scala   |  2 +-
 .../scala/async/run/late/LateExpansion.scala  | 52 ++++++++++++++++++-
 2 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/src/main/scala/scala/async/internal/AnfTransform.scala b/src/main/scala/scala/async/internal/AnfTransform.scala
index fa230999..d697aee9 100644
--- a/src/main/scala/scala/async/internal/AnfTransform.scala
+++ b/src/main/scala/scala/async/internal/AnfTransform.scala
@@ -255,7 +255,7 @@ private[async] trait AnfTransform {
 
             case ValDef(mods, name, tpt, rhs) =>
               if (containsAwait(rhs)) {
-                val stats :+ expr = api.atOwner(api.currentOwner.owner)(linearize.transformToList(rhs))
+                val stats :+ expr = linearize.transformToList(rhs)
                 stats.foreach(_.changeOwner(api.currentOwner, api.currentOwner.owner))
                 stats :+ treeCopy.ValDef(tree, mods, name, tpt, expr)
               } else List(tree)
diff --git a/src/test/scala/scala/async/run/late/LateExpansion.scala b/src/test/scala/scala/async/run/late/LateExpansion.scala
index 5261209b..57bcbfa1 100644
--- a/src/test/scala/scala/async/run/late/LateExpansion.scala
+++ b/src/test/scala/scala/async/run/late/LateExpansion.scala
@@ -443,6 +443,56 @@ class LateExpansion {
       """)
   }
 
+  @Test def testByNameOwner(): Unit = {
+    val result = run(
+      """
+      import scala.async.run.late.{autoawait,lateasync}
+      object Bleh {
+        @autoawait @lateasync def asyncCall(): Int = 0
+        def byName[T](fn: => T): T = fn
+      }
+      object Boffo {
+        @autoawait @lateasync def jerk(): Unit = {
+          val pointlessSymbolOwner = 1 match {
+            case _ =>
+              Bleh.asyncCall()
+              Bleh.byName {
+                val whyDoHateMe = 1
+                whyDoHateMe
+              }
+          }
+        }
+      }
+      object Test {
+        @lateasync def test() = Boffo.jerk()
+      }
+      """)
+  }
+
+  @Test def testByNameOwner2(): Unit = {
+    val result = run(
+      """
+      import scala.async.run.late.{autoawait,lateasync}
+      object Bleh {
+        @autoawait @lateasync def bleh = Bleh
+        def byName[T](fn: => T): T = fn
+      }
+      object Boffo {
+        @autoawait @lateasync def slob(): Unit = {
+          val pointlessSymbolOwner =  {
+              Bleh.bleh.byName {
+                val whyDoHateMeToo = 1
+                whyDoHateMeToo
+              }
+          }
+        }
+      }
+      object Test {
+        @lateasync def test() = Boffo.slob()
+      }
+      """)
+  }
+
   private def createTempDir(): File = {
     val f = File.createTempFile("output", "")
     f.delete()
@@ -455,9 +505,9 @@ class LateExpansion {
     try {
       val reporter = new StoreReporter
       val settings = new Settings(println(_))
-      //settings.processArgumentString("-Xprint:refchecks,patmat,postpatmat,jvm -nowarn")
       settings.outdir.value = out.getAbsolutePath
       settings.embeddedDefaults(getClass.getClassLoader)
+      // settings.processArgumentString("-Xprint:patmat,postpatmat,jvm -nowarn")
       val isInSBT = !settings.classpath.isSetByUser
       if (isInSBT) settings.usejavacp.value = true
       val global = new Global(settings, reporter) {