Fix for broken non-local returns.

Don't change the owner of a return if the new owner is nested
inside the old owner.  Closes SI-5612.

5 files changed, 59 insertions, 3 deletions

diff --git a/src/compiler/scala/reflect/internal/Trees.scala b/src/compiler/scala/reflect/internal/Trees.scala
index 5f1a8f3fbe..c43528b8e9 100644
--- a/src/compiler/scala/reflect/internal/Trees.scala
+++ b/src/compiler/scala/reflect/internal/Trees.scala
@@ -315,11 +315,19 @@ trait Trees extends api.Trees { self: SymbolTable =>
   class ChangeOwnerTraverser(val oldowner: Symbol, val newowner: Symbol) extends Traverser {
     def changeOwner(tree: Tree) = tree match {
       case Return(expr) =>
-        if (tree.symbol == oldowner)
-          tree.symbol = newowner
+        if (tree.symbol == oldowner) {
+          // SI-5612
+          if (newowner hasTransOwner oldowner)
+            log("NOT changing owner of %s because %s is nested in %s".format(tree, newowner, oldowner))
+          else {
+            log("changing owner of %s: %s => %s".format(tree, oldowner, newowner))
+            tree.symbol = newowner
+          }
+        }
       case _: DefTree | _: Function =>
-        if (tree.symbol != NoSymbol && tree.symbol.owner == oldowner)
+        if (tree.symbol != NoSymbol && tree.symbol.owner == oldowner) {
           tree.symbol.owner = newowner
+        }
       case _ =>
     }
     override def traverse(tree: Tree) {
diff --git a/test/files/run/nonlocalreturn.check b/test/files/run/nonlocalreturn.check
new file mode 100644
index 0000000000..aeb2d5e239
--- /dev/null
+++ b/test/files/run/nonlocalreturn.check
@@ -0,0 +1 @@
+Some(1)
diff --git a/test/files/run/nonlocalreturn.scala b/test/files/run/nonlocalreturn.scala
new file mode 100644
index 0000000000..3c1e7420ed
--- /dev/null
+++ b/test/files/run/nonlocalreturn.scala
@@ -0,0 +1,15 @@
+object Test {
+  def wrap[K](body: => K): K = body
+
+  def f(): Option[Int] = {
+    wrap({ return Some(1) ; None })
+  }
+
+  def main(args: Array[String]) {
+    println(f())
+  }
+}
+// java.lang.ClassCastException: scala.Some cannot be cast to scala.None$
+//  at Test$$anonfun$f$1.apply(nonlocalreturn.scala:5)
+//  at Test$$anonfun$f$1.apply(nonlocalreturn.scala:5)
+//  at Test$.wrap(nonlocalreturn.scala:2)
diff --git a/test/files/run/t5612.check b/test/files/run/t5612.check
new file mode 100644
index 0000000000..9d19cca292
--- /dev/null
+++ b/test/files/run/t5612.check
@@ -0,0 +1,4 @@
+START for List(Two, Two, One, Three)
+TWO
+TWO
+ONE
diff --git a/test/files/run/t5612.scala b/test/files/run/t5612.scala
new file mode 100644
index 0000000000..48b3093548
--- /dev/null
+++ b/test/files/run/t5612.scala
@@ -0,0 +1,28 @@
+object L extends Enumeration {
+  val One, Two, Three = Value
+}
+
+class Foo {
+  def foo(xs: List[L.Value]) {
+    import scala.util.control.Breaks.{break, breakable}
+    println("START for " + xs)
+    breakable {
+      for (x <- xs) {
+        x match {
+          case L.One => println("ONE"); return
+          case L.Two => println("TWO")
+          case L.Three => println("THREE"); break
+        }
+      }
+    }
+    println("FINISH")
+  }
+}
+
+object Test {
+  def main(args: Array[String]) {
+    val f = new Foo()
+    val l = List(L.Two, L.Two, L.One, L.Three)
+    f.foo(l)
+  }
+}