diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_step-out.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_step-out.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,85 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Make sure that stepping out of a function displays the right return value.
+ */
+
+const TAB_URL = EXAMPLE_URL + "doc_step-out.html";
+
+let gTab, gDebuggee, gPanel, gDebugger;
+let gVars;
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    gTab = aTab;
+    gDebuggee = aDebuggee;
+    gPanel = aPanel;
+    gDebugger = gPanel.panelWin;
+    gVars = gDebugger.DebuggerView.Variables;
+
+    testNormalReturn();
+  });
+}
+
+function testNormalReturn() {
+  waitForSourceAndCaretAndScopes(gPanel, ".html", 17).then(() => {
+    waitForCaretAndScopes(gPanel, 19).then(() => {
+      let innerScope = gVars.getScopeAtIndex(0);
+      let returnVar = innerScope.get("<return>");
+
+      is(returnVar.name, "<return>",
+        "Should have the right property name for the returned value.");
+      is(returnVar.value, 10,
+        "Should have the right property value for the returned value.");
+
+      resumeDebuggee().then(() => testReturnWithException());
+    });
+
+    EventUtils.sendMouseEvent({ type: "mousedown" },
+      gDebugger.document.getElementById("step-out"),
+      gDebugger);
+  });
+
+  EventUtils.sendMouseEvent({ type: "click" },
+    gDebuggee.document.getElementById("return"),
+    gDebuggee);
+}
+
+function testReturnWithException() {
+  waitForCaretAndScopes(gPanel, 24).then(() => {
+    waitForCaretAndScopes(gPanel, 27).then(() => {
+      let innerScope = gVars.getScopeAtIndex(0);
+      let exceptionVar = innerScope.get("<exception>");
+
+      is(exceptionVar.name, "<exception>",
+        "Should have the right property name for the returned value.");
+      is(exceptionVar.value, "boom",
+        "Should have the right property value for the returned value.");
+
+      resumeDebuggee().then(() => closeDebuggerAndFinish(gPanel));
+    });
+
+    EventUtils.sendMouseEvent({ type: "mousedown" },
+      gDebugger.document.getElementById("step-out"),
+      gDebugger);
+  });
+
+  EventUtils.sendMouseEvent({ type: "click" },
+    gDebuggee.document.getElementById("throw"),
+    gDebuggee);
+}
+
+function resumeDebuggee() {
+  let deferred = promise.defer();
+  gDebugger.gThreadClient.resume(deferred.resolve);
+  return deferred.promise;
+}
+
+registerCleanupFunction(function() {
+  gTab = null;
+  gDebuggee = null;
+  gPanel = null;
+  gDebugger = null;
+  gVars = null;
+});