Fix TDZ check for references

So far we've not been doing the TDZ check for expressions such as
x.name, a[x] and super[x] correctly. Fix this by adding a second
boolean that states whether a tdz check for the subscript is required
and use the first boolean to check the base of these references.

Change-Id: I658cd5b69f001fbdc714f252914ad9749734f027
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 14 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 69b62c733c..99306d8d15 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -356,6 +356,7 @@ private slots:
     void callPropertyOnUndefined();
     void jumpStrictNotEqualUndefined();
     void removeBindingsWithNoDependencies();
+    void temporaryDeadZone();
 
 private:
 //    static void propertyVarWeakRefCallback(v8::Persistent<v8::Value> object, void* parameter);
@@ -8798,6 +8799,19 @@ void tst_qqmlecmascript::removeBindingsWithNoDependencies()
 
 }
 
+void tst_qqmlecmascript::temporaryDeadZone()
+{
+    QJSEngine engine;
+    QJSValue v = engine.evaluate(QString::fromLatin1("a; let a;"));
+    QVERIFY(v.isError());
+    v = engine.evaluate(QString::fromLatin1("a.name; let a;"));
+    QVERIFY(v.isError());
+    v = engine.evaluate(QString::fromLatin1("var a = {}; a[b]; let b;"));
+    QVERIFY(v.isError());
+    v = engine.evaluate(QString::fromLatin1("class C { constructor() { super[x]; let x; } }; new C()"));
+    QVERIFY(v.isError());
+}
+
 QTEST_MAIN(tst_qqmlecmascript)
 
 #include "tst_qqmlecmascript.moc"