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>

1 files changed, 9 insertions, 4 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());