[ChangeLog][QtQml] Fix JavaScript Array.pop() not updating the internal array length correctly

While the length property was reporting the correct value, the internal array
length was out-of-sync.

Task-number: QTBUG-35979

Change-Id: I68820a349cf1ce88c6aabc6a2301a8a861018a10
Reviewed-by: Liang Qi <[email protected]>
Reviewed-by: Lars Knoll <[email protected]>

2 files changed, 14 insertions, 1 deletions

diff --git a/src/qml/jsruntime/qv4arrayobject.cpp b/src/qml/jsruntime/qv4arrayobject.cpp
index 1628cfe4da..296471692c 100644
--- a/src/qml/jsruntime/qv4arrayobject.cpp
+++ b/src/qml/jsruntime/qv4arrayobject.cpp
@@ -276,7 +276,7 @@ ReturnedValue ArrayPrototype::method_pop(CallContext *ctx)
     if (scope.hasException())
         return Encode::undefined();
     if (instance->isArrayObject())
-        instance->setArrayLengthUnchecked(len - 1);
+        instance->setArrayLength(len - 1);
     else
         instance->put(ctx->engine->id_length, ScopedValue(scope, Primitive::fromDouble(len - 1)));
     return result.asReturnedValue();
diff --git a/tests/auto/qml/qjsengine/tst_qjsengine.cpp b/tests/auto/qml/qjsengine/tst_qjsengine.cpp
index 726f8636b6..a1662b495c 100644
--- a/tests/auto/qml/qjsengine/tst_qjsengine.cpp
+++ b/tests/auto/qml/qjsengine/tst_qjsengine.cpp
@@ -146,6 +146,8 @@ private slots:
     void threadedEngine();
 
     void functionDeclarationsInConditionals();
+
+    void arrayPop_QTBUG_35979();
 };
 
 tst_QJSEngine::tst_QJSEngine()
@@ -2692,6 +2694,17 @@ void tst_QJSEngine::functionDeclarationsInConditionals()
     QCOMPARE(result.toBool(), true);
 }
 
+void tst_QJSEngine::arrayPop_QTBUG_35979()
+{
+    QJSEngine eng;
+    QJSValue result = eng.evaluate(""
+            "var x = [1, 2]\n"
+            "x.pop()\n"
+            "x[1] = 3\n"
+            "x.toString()\n");
+    QCOMPARE(result.toString(), QString("1,3"));
+}
+
 QTEST_MAIN(tst_QJSEngine)
 
 #include "tst_qjsengine.moc"