diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_variables-view-edit-cancel.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_variables-view-edit-cancel.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,53 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Make sure that canceling a name change correctly unhides the separator and
+ * value elements.
+ */
+
+const TAB_URL = EXAMPLE_URL + "doc_watch-expressions.html";
+
+function test() {
+  Task.spawn(function*() {
+    let [tab, debuggee, panel] = yield initDebugger(TAB_URL);
+    let win = panel.panelWin;
+    let vars = win.DebuggerView.Variables;
+
+    win.DebuggerView.WatchExpressions.addExpression("this");
+
+    // Allow this generator function to yield first.
+    executeSoon(() => debuggee.ermahgerd());
+    yield waitForDebuggerEvents(panel, win.EVENTS.FETCHED_WATCH_EXPRESSIONS);
+
+    let exprScope = vars.getScopeAtIndex(0);
+    let {target} = exprScope.get("this");
+
+    let name = target.querySelector(".title > .name");
+    let separator = target.querySelector(".separator");
+    let value = target.querySelector(".value");
+
+    is(separator.hidden, false,
+      "The separator element should not be hidden.");
+    is(value.hidden, false,
+      "The value element should not be hidden.");
+
+    for (let key of ["ESCAPE", "RETURN"]) {
+      EventUtils.sendMouseEvent({ type: "dblclick" }, name, win);
+
+      is(separator.hidden, true,
+        "The separator element should be hidden.");
+      is(value.hidden, true,
+        "The value element should be hidden.");
+
+      EventUtils.sendKey(key, win);
+
+      is(separator.hidden, false,
+        "The separator element should not be hidden.");
+      is(value.hidden, false,
+        "The value element should not be hidden.");
+    }
+
+    yield resumeDebuggerThenCloseAndFinish(panel);
+  });
+}