Only warn about incompatible parameter types passed from QML

Throwing a TypeError is too drastic. We need to properly deprecate this
pattern before we actually enforce the compatibility.

Fixes: QTBUG-73943
Change-Id: I00313ad7aed4021a7368fd014e2bfc6443b177e3
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 48 insertions, 39 deletions

diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index 6617dd5e89..40be6f41c8 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -1206,8 +1206,20 @@ static QV4::ReturnedValue CallMethod(const QQmlObjectOrGadget &object, int index
         args[0].initAsType(returnType);
         for (int ii = 0; ii < argCount; ++ii) {
             if (!args[ii + 1].fromValue(argTypes[ii], engine, callArgs->args[ii])) {
-                return engine->throwTypeError(QString::fromLatin1("Could not convert argument %1.")
-                                                      .arg(ii));
+                qWarning() << QString::fromLatin1("Could not convert argument %1 at").arg(ii);
+                const StackTrace stack = engine->stackTrace();
+                for (const StackFrame &frame : stack) {
+                    qWarning() << "\t" << frame.function + QLatin1Char('@') + frame.source
+                                    + (frame.line > 0
+                                               ? (QLatin1Char(':') + QString::number(frame.line))
+                                               : 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!");
+
             }
         }
         QVarLengthArray<void *, 9> argData(args.count());
@@ -1724,6 +1736,7 @@ bool CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const Q
         type = callType;
     } else if (callType == qMetaTypeId<QList<QObject*> >()) {
         qlistPtr = new (&allocData) QList<QObject *>();
+        type = callType;
         QV4::ScopedArrayObject array(scope, value);
         if (array) {
             Scoped<QV4::QObjectWrapper> qobjectWrapper(scope);
@@ -1737,14 +1750,14 @@ bool CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const Q
                 qlistPtr->append(o);
             }
         } else {
-            QObject *o = nullptr;
-            if (const QV4::QObjectWrapper *qobjectWrapper = value.as<QV4::QObjectWrapper>())
-                o = qobjectWrapper->object();
-            else if (!value.isNull() && !value.isUndefined())
-                return false;
-            qlistPtr->append(o);
+            if (const QV4::QObjectWrapper *qobjectWrapper = value.as<QV4::QObjectWrapper>()) {
+                qlistPtr->append(qobjectWrapper->object());
+            } else {
+                qlistPtr->append(nullptr);
+                if (!value.isNull() && !value.isUndefined())
+                    return false;
+            }
         }
-        type = callType;
     } else if (callType == qMetaTypeId<QQmlV4Handle>()) {
         handlePtr = new (&allocData) QQmlV4Handle(value.asReturnedValue());
         type = callType;
diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 6a97fc5d8b..788ecce1c5 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -2762,28 +2762,32 @@ 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_VALUE("object.method_QPointF(0)", QV4::Primitive::undefinedValue()));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), -1);
-    QCOMPARE(o->actuals().count(), 0);
+    QCOMPARE(o->invoked(), 12);
+    QCOMPARE(o->actuals().count(), 1);
+    QCOMPARE(o->actuals().at(0), QVariant(QPointF()));
 
     o->reset();
-    QVERIFY(!EVALUATE_VALUE("object.method_QPointF(null)", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_VALUE("object.method_QPointF(null)", QV4::Primitive::undefinedValue()));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), -1);
-    QCOMPARE(o->actuals().count(), 0);
+    QCOMPARE(o->invoked(), 12);
+    QCOMPARE(o->actuals().count(), 1);
+    QCOMPARE(o->actuals().at(0), QVariant(QPointF()));
 
     o->reset();
-    QVERIFY(!EVALUATE_VALUE("object.method_QPointF(undefined)", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_VALUE("object.method_QPointF(undefined)", QV4::Primitive::undefinedValue()));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), -1);
-    QCOMPARE(o->actuals().count(), 0);
+    QCOMPARE(o->invoked(), 12);
+    QCOMPARE(o->actuals().count(), 1);
+    QCOMPARE(o->actuals().at(0), QVariant(QPointF()));
 
     o->reset();
-    QVERIFY(!EVALUATE_VALUE("object.method_QPointF(object)", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_VALUE("object.method_QPointF(object)", QV4::Primitive::undefinedValue()));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), -1);
-    QCOMPARE(o->actuals().count(), 0);
+    QCOMPARE(o->invoked(), 12);
+    QCOMPARE(o->actuals().count(), 1);
+    QCOMPARE(o->actuals().at(0), QVariant(QPointF()));
 
     o->reset();
     QVERIFY(EVALUATE_VALUE("object.method_QPointF(object.method_get_QPointF())", QV4::Primitive::undefinedValue()));
@@ -2800,16 +2804,18 @@ 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_VALUE("object.method_QObject(0)", QV4::Primitive::undefinedValue()));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), -1);
-    QCOMPARE(o->actuals().count(), 0);
+    QCOMPARE(o->invoked(), 13);
+    QCOMPARE(o->actuals().count(), 1);
+    QCOMPARE(o->actuals().at(0), qVariantFromValue((QObject *)nullptr));
 
     o->reset();
-    QVERIFY(!EVALUATE_VALUE("object.method_QObject(\"Hello world\")", QV4::Primitive::undefinedValue()));
+    QVERIFY(EVALUATE_VALUE("object.method_QObject(\"Hello world\")", QV4::Primitive::undefinedValue()));
     QCOMPARE(o->error(), false);
-    QCOMPARE(o->invoked(), -1);
-    QCOMPARE(o->actuals().count(), 0);
+    QCOMPARE(o->invoked(), 13);
+    QCOMPARE(o->actuals().count(), 1);
+    QCOMPARE(o->actuals().at(0), qVariantFromValue((QObject *)nullptr));
 
     o->reset();
     QVERIFY(EVALUATE_VALUE("object.method_QObject(null)", QV4::Primitive::undefinedValue()));
diff --git a/tests/auto/qml/qqmllanguage/data/SignalEmitter.qml b/tests/auto/qml/qqmllanguage/data/SignalEmitter.qml
index 31fe5e4a5e..259f45b7d2 100644
--- a/tests/auto/qml/qqmllanguage/data/SignalEmitter.qml
+++ b/tests/auto/qml/qqmllanguage/data/SignalEmitter.qml
@@ -10,18 +10,8 @@ QtObject {
     signal testSignal(SignalParam spp);
 
     function emitTestSignal() {
-        var caught = false;
-        try {
-            testObject.expectNull = true;
-            testSignal(op);
-        } catch(e) {
-            // good: We want a type error here
-            caught = true;
-            if (handleSignal)
-                testObject.determineSuccess(null);
-        }
-        if (!caught && handleSignal)
-            testObject.determineSuccess("fail");
+        testObject.expectNull = true;
+        testSignal(op);
 
         testObject.expectNull = false;
         testSignal(p);