Fix JITted code for jump strict-not-equal undefined on 32bit

The generated code for jump-on-strict-not-equal-undefined used the
same logic (but with inverted conditions) as the equal case. For
equality, one can jump to else if the value parts are not the same.
So, for not-equal, if the value parts are the same, it would jump
to the else block if they are the same. Meaning, an encoded int
value of 0 (which is strict-not-equal to undefined) would end up
being evaluated as equal.

Task-number: QTBUG-66832
Change-Id: I5c6b8e9b11be53ae21a7164e0a1e0cbfd204f401
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
(cherry picked from commit 86702c3be53fda404ebe331207f9062675c952e0)

1 files changed, 21 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 6318b12f9f..172fb8f91c 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -340,6 +340,7 @@ private slots:
     void qtbug_60547();
     void anotherNaN();
     void callPropertyOnUndefined();
+    void jumpStrictNotEqualUndefined();
 
 private:
 //    static void propertyVarWeakRefCallback(v8::Persistent<v8::Value> object, void* parameter);
@@ -8294,6 +8295,26 @@ void tst_qqmlecmascript::callPropertyOnUndefined()
     QVERIFY(!v.isError()); // well, more importantly: this shouldn't fail on an assert.
 }
 
+void tst_qqmlecmascript::jumpStrictNotEqualUndefined()
+{
+    QJSEngine engine;
+    QJSValue v = engine.evaluate(QString::fromLatin1(
+        "var ok = 0\n"
+        "var foo = 0\n"
+        "if (foo !== void 1)\n"
+        "    ++ok;\n"
+        "else\n"
+        "    --ok;\n"
+        "if (foo === void 1)\n"
+        "    --ok;\n"
+        "else\n"
+        "    ++ok;\n"
+        "ok\n"
+    ));
+    QVERIFY(!v.isError());
+    QCOMPARE(v.toInt(), 2);
+}
+
 QTEST_MAIN(tst_qqmlecmascript)
 
 #include "tst_qqmlecmascript.moc"