diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_variables-view-edit-click.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_variables-view-edit-click.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,52 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Check that the editing state of a Variable is correctly tracked. Clicking on
+ * the textbox while editing should not cancel editing.
+ */
+
+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 exprVar = exprScope.get("this");
+    let name = exprVar.target.querySelector(".title > .name");
+
+    is(exprVar.editing, false,
+      "The expression should indicate it is not being edited.");
+
+    EventUtils.sendMouseEvent({ type: "dblclick" }, name, win);
+    let input = exprVar.target.querySelector(".title > .element-name-input");
+    is(exprVar.editing, true,
+      "The expression should indicate it is being edited.");
+    is(input.selectionStart !== input.selectionEnd, true,
+      "The expression text should be selected.");
+
+    EventUtils.synthesizeMouse(input, 2, 2, {}, win);
+    is(exprVar.editing, true,
+      "The expression should indicate it is still being edited after a click.");
+    is(input.selectionStart === input.selectionEnd, true,
+      "The expression text should not be selected.");
+
+    EventUtils.sendKey("ESCAPE", win);
+    is(exprVar.editing, false,
+      "The expression should indicate it is not being edited after cancelling.");
+
+    // Why is this needed?
+    EventUtils.synthesizeMouse(vars.parentNode, 2, 2, {}, win);
+
+    yield resumeDebuggerThenCloseAndFinish(panel);
+  });
+}