From 63bf6ac4c483cc64b48c410c6e1afb404f2bcbd1 Mon Sep 17 00:00:00 2001
From: Maximilian Goldstein <max.goldstein@qt.io>
Date: Wed, 1 Apr 2020 08:06:30 +0200
Subject: [PATCH] Throw an error if an incompatible parameter is passed to a
 C++ function

[ChangeLog][Important Behavior Changes][QML] Throw an error if an incompatible parameter is passed to a C++ function

Change-Id: I088e362869f7dc00ca639a0fbc4ba20cb9e82f7d
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
---
 src/qml/jsruntime/qv4qobjectwrapper.cpp       | 13 ++++--
 .../qml/qqmlecmascript/tst_qqmlecmascript.cpp | 42 ++++++++-----------
 2 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index ea809064a3..720324ea42 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -1298,11 +1298,16 @@ static QV4::ReturnedValue CallMethod(const QQmlObjectOrGadget &object, int index
                                                : QString());
 
                 }
-                qWarning() << QLatin1String("Passing incompatible arguments to C++ functions from "
-                                            "JavaScript is dangerous and deprecated.");
-                qWarning() << QLatin1String("This will throw a JavaScript TypeError in future "
-                                            "releases of Qt!");
 
+                const bool is_signal =
+                        object.metaObject()->method(index).methodType() == QMetaMethod::Signal;
+                if (is_signal) {
+                    qWarning() << "Passing incomatible arguments to signals is not supported.";
+                } else {
+                    return engine->throwTypeError(
+                            "Passing incompatible arguments to C++ functions from "
+                            "JavaScript is not allowed.");
+                }
             }
         }
         QVarLengthArray<void *, 9> argData(args.count());
diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 5dfe76c2f2..2a23d7ec60 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -2906,32 +2906,28 @@ void tst_qqmlecmascript::callQtInvokables()
     QCOMPARE(o->actuals().at(0), QVariant(QString()));
 
     o->reset();
-    QVERIFY(EVALUATE_VALUE("object.method_QPointF(0)", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_ERROR("object.method_QPointF(0)"));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), 12);
-    QCOMPARE(o->actuals().count(), 1);
-    QCOMPARE(o->actuals().at(0), QVariant(QPointF()));
+    QCOMPARE(o->invoked(), -1);
+    QCOMPARE(o->actuals().count(), 0);
 
     o->reset();
-    QVERIFY(EVALUATE_VALUE("object.method_QPointF(null)", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_ERROR("object.method_QPointF(null)"));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), 12);
-    QCOMPARE(o->actuals().count(), 1);
-    QCOMPARE(o->actuals().at(0), QVariant(QPointF()));
+    QCOMPARE(o->invoked(), -1);
+    QCOMPARE(o->actuals().count(), 0);
 
     o->reset();
-    QVERIFY(EVALUATE_VALUE("object.method_QPointF(undefined)", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_ERROR("object.method_QPointF(undefined)"));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), 12);
-    QCOMPARE(o->actuals().count(), 1);
-    QCOMPARE(o->actuals().at(0), QVariant(QPointF()));
+    QCOMPARE(o->invoked(), -1);
+    QCOMPARE(o->actuals().count(), 0);
 
     o->reset();
-    QVERIFY(EVALUATE_VALUE("object.method_QPointF(object)", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_ERROR("object.method_QPointF(object)"));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), 12);
-    QCOMPARE(o->actuals().count(), 1);
-    QCOMPARE(o->actuals().at(0), QVariant(QPointF()));
+    QCOMPARE(o->invoked(), -1);
+    QCOMPARE(o->actuals().count(), 0);
 
     o->reset();
     QVERIFY(EVALUATE_VALUE("object.method_QPointF(object.method_get_QPointF())", QV4::Primitive::undefinedValue()));
@@ -2948,18 +2944,16 @@ void tst_qqmlecmascript::callQtInvokables()
     QCOMPARE(o->actuals().at(0), QVariant(QPointF(9, 12)));
 
     o->reset();
-    QVERIFY(EVALUATE_VALUE("object.method_QObject(0)", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_ERROR("object.method_QObject(0)"));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), 13);
-    QCOMPARE(o->actuals().count(), 1);
-    QCOMPARE(o->actuals().at(0), QVariant::fromValue((QObject *)nullptr));
+    QCOMPARE(o->invoked(), -1);
+    QCOMPARE(o->actuals().count(), 0);
 
     o->reset();
-    QVERIFY(EVALUATE_VALUE("object.method_QObject(\"Hello world\")", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_ERROR("object.method_QObject(\"Hello world\")"));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), 13);
-    QCOMPARE(o->actuals().count(), 1);
-    QCOMPARE(o->actuals().at(0), QVariant::fromValue((QObject *)nullptr));
+    QCOMPARE(o->invoked(), -1);
+    QCOMPARE(o->actuals().count(), 0);
 
     o->reset();
     QVERIFY(EVALUATE_VALUE("object.method_QObject(null)", QV4::Primitive::undefinedValue()));