1 files changed, 27 insertions, 8 deletions

diff --git a/src/qmlcompiler/qqmljscodegenerator.cpp b/src/qmlcompiler/qqmljscodegenerator.cpp
index cd325ae971..4dcf2af294 100644
--- a/src/qmlcompiler/qqmljscodegenerator.cpp
+++ b/src/qmlcompiler/qqmljscodegenerator.cpp
@@ -382,8 +382,11 @@ void QQmlJSCodeGenerator::eliminateDeadStores()
 
 QString QQmlJSCodeGenerator::errorReturnValue() const
 {
-    if (m_function->returnType)
-        return conversion(m_typeResolver->voidType(), m_function->returnType, QString());
+    if (auto ret = m_function->returnType) {
+        return ret->accessSemantics() == QQmlJSScope::AccessSemantics::Reference
+                ? conversion(m_typeResolver->voidType(), ret, QString()) // produces nullptr
+                : ret->internalName() + u"()"_qs;
+    }
     return QString();
 }
 
@@ -586,8 +589,11 @@ void QQmlJSCodeGenerator::generate_LoadReg(int reg)
 void QQmlJSCodeGenerator::generate_StoreReg(int reg)
 {
     INJECT_TRACE_INFO(generate_StoreReg);
-
     Q_ASSERT(m_state.accumulatorIn.isValid());
+
+    if (isArgument(reg))
+        reject(u"writing into a function argument"_qs);
+
     const QString var = registerVariable(reg);
     m_body.setWriteRegister(var);
     if (var.isEmpty())
@@ -812,6 +818,15 @@ void QQmlJSCodeGenerator::generate_LoadElement(int base)
     const QString baseName = use(registerVariable(base));
     const QString indexName = use(m_state.accumulatorVariableIn);
 
+    const QString voidAssignment = u"    "_qs + m_state.accumulatorVariableOut + u" = "_qs +
+            conversion(m_typeResolver->globalType(m_typeResolver->voidType()),
+                       m_state.accumulatorOut, QString()) + u";\n"_qs;
+
+    if (!m_typeResolver->isIntegral(m_state.accumulatorIn)) {
+        m_body += u"if (!QJSNumberCoercion::isInteger("_qs + indexName + u"))\n"_qs
+                + voidAssignment
+                + u"else "_qs;
+    }
     // Our QQmlListProperty only keeps plain QObject*.
     const auto valueType = m_typeResolver->valueType(baseType);
     const auto elementType = m_typeResolver->globalType(
@@ -824,9 +839,8 @@ void QQmlJSCodeGenerator::generate_LoadElement(int base)
             conversion(elementType, m_state.accumulatorOut,
                        baseName + u".at(&"_qs + baseName + u", "_qs
                        + indexName + u')') + u";\n"_qs;
-    m_body += u"else\n"_qs;
-    m_body += u"    "_qs + m_state.accumulatorVariableOut + u" = {}"_qs;
-    m_body += u";\n"_qs;
+    m_body += u"else\n"_qs
+            + voidAssignment;
 }
 
 void QQmlJSCodeGenerator::generate_StoreElement(int base, int index)
@@ -837,6 +851,7 @@ void QQmlJSCodeGenerator::generate_StoreElement(int base, int index)
     m_body.setWriteRegister(QString());
 
     const QQmlJSRegisterContent baseType = registerType(base);
+    const QQmlJSRegisterContent indexType = registerType(index);
 
     if (!m_typeResolver->isNumeric(registerType(index)) || !baseType.isList()) {
         reject(u"StoreElement with non-list base type or non-numeric arguments"_qs);
@@ -855,8 +870,11 @@ void QQmlJSCodeGenerator::generate_StoreElement(int base, int index)
     const auto elementType = m_typeResolver->globalType(m_typeResolver->genericType(
                                           m_typeResolver->containedType(valueType)));
 
-    m_body += u"if ("_qs + indexName + u" >= 0 && "_qs + indexName
-            + u" < "_qs + baseName + u".count(&"_qs + baseName
+    m_body += u"if ("_qs;
+    if (!m_typeResolver->isIntegral(indexType))
+        m_body += u"QJSNumberCoercion::isInteger("_qs + indexName + u") && "_qs;
+    m_body += indexName + u" >= 0 && "_qs
+            + indexName + u" < "_qs + baseName + u".count(&"_qs + baseName
             + u"))\n"_qs;
     m_body += u"    "_qs + baseName + u".replace(&"_qs + baseName
             + u", "_qs + indexName + u", "_qs;
@@ -1601,6 +1619,7 @@ void QQmlJSCodeGenerator::generate_ThrowException()
                          m_typeResolver->jsValueType()),
                      use(m_state.accumulatorVariableIn)) + u");\n"_qs;
     m_body += u"return "_qs + errorReturnValue() + u";\n"_qs;
+    m_skipUntilNextLabel = true;
 }
 
 void QQmlJSCodeGenerator::generate_GetException()