Arguments passed to functions should shadow the function name

Task-number: QTBUG-65140
Change-Id: I6c6b24f081b31ef0f16fec9b2024485acec11c2d
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 25 insertions, 6 deletions

diff --git a/src/qml/compiler/qv4compilerscanfunctions.cpp b/src/qml/compiler/qv4compilerscanfunctions.cpp
index 6a9b064bd8..808e79959d 100644
--- a/src/qml/compiler/qv4compilerscanfunctions.cpp
+++ b/src/qml/compiler/qv4compilerscanfunctions.cpp
@@ -130,13 +130,15 @@ void ScanFunctions::checkName(const QStringRef &name, const SourceLocation &loc)
         }
     }
 }
-void ScanFunctions::checkForArguments(AST::FormalParameterList *parameters)
+
+bool ScanFunctions::formalsContainName(AST::FormalParameterList *parameters, const QString &name)
 {
     while (parameters) {
-        if (parameters->name == QLatin1String("arguments"))
-            _context->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+        if (parameters->name == name)
+            return true;
         parameters = parameters->next;
     }
+    return false;
 }
 
 bool ScanFunctions::visit(Program *ast)
@@ -398,9 +400,11 @@ void ScanFunctions::enterFunction(Node *ast, const QString &name, FormalParamete
     }
 
     enterEnvironment(ast, FunctionCode);
-    checkForArguments(formals);
+    if (formalsContainName(formals, QStringLiteral("arguments")))
+        _context->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+
 
-    if (!name.isEmpty())
+    if (!name.isEmpty() && !formalsContainName(formals, name))
         _context->addLocalVar(name, Context::ThisFunctionName, QQmlJS::AST::VariableDeclaration::FunctionScope);
     _context->formals = formals;
 
diff --git a/src/qml/compiler/qv4compilerscanfunctions_p.h b/src/qml/compiler/qv4compilerscanfunctions_p.h
index 0b898e587d..526278fdd8 100644
--- a/src/qml/compiler/qv4compilerscanfunctions_p.h
+++ b/src/qml/compiler/qv4compilerscanfunctions_p.h
@@ -100,7 +100,7 @@ protected:
     void checkDirectivePrologue(AST::SourceElements *ast);
 
     void checkName(const QStringRef &name, const AST::SourceLocation &loc);
-    void checkForArguments(AST::FormalParameterList *parameters);
+    bool formalsContainName(AST::FormalParameterList *parameters, const QString &name);
 
     bool visit(AST::Program *ast) override;
     void endVisit(AST::Program *) override;
diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 64cf27ae1f..8913fa2f2e 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -347,6 +347,7 @@ private slots:
     void manyArguments();
     void forInIterator();
     void localForInIterator();
+    void shadowedFunctionName();
 
 private:
 //    static void propertyVarWeakRefCallback(v8::Persistent<v8::Value> object, void* parameter);
@@ -8423,6 +8424,20 @@ void tst_qqmlecmascript::localForInIterator()
     QCOMPARE(ret.toString(), QStringLiteral("3"));
 }
 
+void tst_qqmlecmascript::shadowedFunctionName()
+{
+    // verify that arguments shadow the function name
+    QJSEngine engine;
+    QJSValue v = engine.evaluate(QString::fromLatin1(
+            "function f(f) { return f; }\n"
+            "f(true)\n"
+                        ));
+    QVERIFY(!v.isError());
+    QVERIFY(v.isBool());
+    QCOMPARE(v.toBool(), true);
+}
+
+
 
 QTEST_MAIN(tst_qqmlecmascript)