Merge "Merge remote-tracking branch 'origin/5.9' into 5.10" into refs/staging/5.10

83 files changed, 1065 insertions, 314 deletions

diff --git a/dist/changes-5.6.3 b/dist/changes-5.6.3
new file mode 100644
index 0000000000..3dfc21eb39
--- /dev/null
+++ b/dist/changes-5.6.3
@@ -0,0 +1,78 @@
+Qt 5.6.3 is a bug-fix release. It maintains both forward and backward
+compatibility (source and binary) with Qt 5.6.0.
+
+For more details, refer to the online documentation included in this
+distribution. The documentation is also available online:
+
+  http://doc.qt.io/qt-5/index.html
+
+The Qt version 5.6 series is binary compatible with the 5.5.x series.
+Applications compiled for 5.5 will continue to run with 5.6.
+
+Some of the changes listed in this file include issue tracking numbers
+corresponding to tasks in the Qt Bug Tracker:
+
+  https://bugreports.qt.io/
+
+Each of these identifiers can be entered in the bug tracker to obtain more
+information about a particular change.
+
+QQuickWindow
+------------
+
+ - The relevant child item is now sent a hover event when the window
+   receives a QEnterEvent, making sure hovering is recognized without
+   waiting for mouse movement.
+ - [QTBUG-56075] Wheel events retain their timestamps during delivery.
+
+QtQml
+-----
+
+ - Fixed reading of enum properties from gadgets / value types when the
+   enum was registered with qRegisterMetaType().
+ - [QTBUG-56271] Fixed a crash on big-endian architecture.
+ - [QTBUG-50592] JSON.stringify() uses QVariant::toString() so that URLs
+   and other types which are stored as variants will not be omitted.
+ - [QTBUG-56658] Fixed a crash in the Qt Quick compiler.
+ - [QTBUG-56830] Fixed conversion of long numeric strings to integers.
+ - [QTBUG-52356] Fixed binding re-evaluation when list model properties change.
+ - [QTBUG-58133] Fixed a crash when emitting a signal with an undefined QJSValue.
+ - [QTBUG-57633][QTBUG-46263] Fix crash with QObjects exposed to multiple QML engines.
+ - [QTBUG-58271] Fix PropertyChanges element to restore bindings on aliases.
+ - [QTBUG-56499] Fix Connection element not disconnecting when target became null.
+ - Work around crashes with gcc 5/6 caused by dead-store eliminations.
+ - Fix memory leak with QQmlExpression.
+ - [QTBUG-53261] Fix memory corruption when changing JS object properties in
+   certain ways.
+ - [QTBUG-39888] Fix crash with QQuickItem objects that do not have a parent but
+   should be kept alive by the JS garbage collector.
+ - [QTBUG-54822] Fix support for address space configurations where the kernel uses
+   more bits in pointer addressing
+ - [QTBUG-56551] Fix crash with Connection element and non-existent objects
+
+QtQuick
+-------
+
+ - [QTBUG-39888] Fixed crash with QQuickItems created via JavaScript being
+   garbage collected sometimes when they're not assigned to a window.
+ - [QTBUG-44038] TextInput no longer emits editingFinished twice on iOS.
+ - [QTBUG-55871][QTBUG-55886] Flickable::movementEnding and movementEnded
+   are emitted reliably at the right times on macOS.
+ - [QTBUG-55779] Text padding now has the proper effect on height when
+   there is more than one line of text.
+ - [QTBUG-37095] Canvas is rendered at high resolution if the scene is
+   initially rendered on a high-DPI screen.
+ - [QTBUG-56657] Fixed a bug resulting in invisible images in some cases.
+ - [QTBUG-58852] Large amounts of text are now rendered properly with
+   Text.NativeRendering.
+
+QuickTest
+---------
+ - [QTBUG-56223] Mouse events now include timestamps.
+
+QtWidgets
+---------
+
+ - [QTBUG-42074][QTBUG-57003] Support characters in Private Use Area, as
+   well as zero-width joiners and zero-width non-joiners in input in
+   TextInput and TextEdit.
diff --git a/src/imports/settings/qqmlsettings.cpp b/src/imports/settings/qqmlsettings.cpp
index ed2f58e7c1..f6040e7a64 100644
--- a/src/imports/settings/qqmlsettings.cpp
+++ b/src/imports/settings/qqmlsettings.cpp
@@ -189,6 +189,9 @@ QT_BEGIN_NAMESPACE
     only provides a cleaner settings structure, but also prevents possible
     conflicts between setting keys.
 
+    If several categories are required, use several Settings objects, each with
+    their own category:
+
     \qml
     Item {
         id: panel
@@ -200,6 +203,12 @@ QT_BEGIN_NAMESPACE
             property alias visible: panel.visible
             // ...
         }
+
+        Settings {
+            category: "General"
+            property alias fontSize: fontSizeSpinBox.value
+            // ...
+        }
     }
     \endqml
 
diff --git a/src/plugins/qmltooling/qmldbg_profiler/qqmlprofileradapter.cpp b/src/plugins/qmltooling/qmldbg_profiler/qqmlprofileradapter.cpp
index 510c745d4e..d676731ba7 100644
--- a/src/plugins/qmltooling/qmldbg_profiler/qqmlprofileradapter.cpp
+++ b/src/plugins/qmltooling/qmldbg_profiler/qqmlprofileradapter.cpp
@@ -44,24 +44,36 @@
 
 QT_BEGIN_NAMESPACE
 
-QQmlProfilerAdapter::QQmlProfilerAdapter(QQmlProfilerService *service, QQmlEnginePrivate *engine) :
-    next(0)
+QQmlProfilerAdapter::QQmlProfilerAdapter(QQmlProfilerService *service, QQmlEnginePrivate *engine)
 {
-    setService(service);
     engine->profiler = new QQmlProfiler;
+    init(service, engine->profiler);
+}
+
+QQmlProfilerAdapter::QQmlProfilerAdapter(QQmlProfilerService *service, QQmlTypeLoader *loader)
+{
+    QQmlProfiler *profiler = new QQmlProfiler;
+    loader->setProfiler(profiler);
+    init(service, profiler);
+}
+
+void QQmlProfilerAdapter::init(QQmlProfilerService *service, QQmlProfiler *profiler)
+{
+    next = 0;
+    setService(service);
     connect(this, &QQmlProfilerAdapter::profilingEnabled,
-            engine->profiler, &QQmlProfiler::startProfiling);
+            profiler, &QQmlProfiler::startProfiling);
     connect(this, &QQmlAbstractProfilerAdapter::profilingEnabledWhileWaiting,
-            engine->profiler, &QQmlProfiler::startProfiling, Qt::DirectConnection);
+            profiler, &QQmlProfiler::startProfiling, Qt::DirectConnection);
     connect(this, &QQmlAbstractProfilerAdapter::profilingDisabled,
-            engine->profiler, &QQmlProfiler::stopProfiling);
+            profiler, &QQmlProfiler::stopProfiling);
     connect(this, &QQmlAbstractProfilerAdapter::profilingDisabledWhileWaiting,
-            engine->profiler, &QQmlProfiler::stopProfiling, Qt::DirectConnection);
+            profiler, &QQmlProfiler::stopProfiling, Qt::DirectConnection);
     connect(this, &QQmlAbstractProfilerAdapter::dataRequested,
-            engine->profiler, &QQmlProfiler::reportData);
+            profiler, &QQmlProfiler::reportData);
     connect(this, &QQmlAbstractProfilerAdapter::referenceTimeKnown,
-            engine->profiler, &QQmlProfiler::setTimer);
-    connect(engine->profiler, &QQmlProfiler::dataReady,
+            profiler, &QQmlProfiler::setTimer);
+    connect(profiler, &QQmlProfiler::dataReady,
             this, &QQmlProfilerAdapter::receiveData);
 }
 
diff --git a/src/plugins/qmltooling/qmldbg_profiler/qqmlprofileradapter.h b/src/plugins/qmltooling/qmldbg_profiler/qqmlprofileradapter.h
index 1fee5c389f..7531cd1dff 100644
--- a/src/plugins/qmltooling/qmldbg_profiler/qqmlprofileradapter.h
+++ b/src/plugins/qmltooling/qmldbg_profiler/qqmlprofileradapter.h
@@ -60,6 +60,7 @@ class QQmlProfilerAdapter : public QQmlAbstractProfilerAdapter {
     Q_OBJECT
 public:
     QQmlProfilerAdapter(QQmlProfilerService *service, QQmlEnginePrivate *engine);
+    QQmlProfilerAdapter(QQmlProfilerService *service, QQmlTypeLoader *loader);
     qint64 sendMessages(qint64 until, QList<QByteArray> &messages,
                         bool trackLocations) Q_DECL_OVERRIDE;
 
@@ -67,6 +68,7 @@ public:
                      const QQmlProfiler::LocationHash &locations);
 
 private:
+    void init(QQmlProfilerService *service, QQmlProfiler *profiler);
     QVector<QQmlProfilerData> data;
     QQmlProfiler::LocationHash locations;
     int next;
diff --git a/src/plugins/qmltooling/qmldbg_profiler/qqmlprofilerservice.cpp b/src/plugins/qmltooling/qmldbg_profiler/qqmlprofilerservice.cpp
index edeb364f60..4176ede40e 100644
--- a/src/plugins/qmltooling/qmldbg_profiler/qqmlprofilerservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_profiler/qqmlprofilerservice.cpp
@@ -119,9 +119,12 @@ void QQmlProfilerServiceImpl::engineAboutToBeAdded(QJSEngine *engine)
 
     QMutexLocker lock(&m_configMutex);
     if (QQmlEngine *qmlEngine = qobject_cast<QQmlEngine *>(engine)) {
-        QQmlProfilerAdapter *qmlAdapter =
-                new QQmlProfilerAdapter(this, QQmlEnginePrivate::get(qmlEngine));
+        QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(qmlEngine);
+        QQmlProfilerAdapter *qmlAdapter = new QQmlProfilerAdapter(this, enginePrivate);
         addEngineProfiler(qmlAdapter, engine);
+        QQmlProfilerAdapter *compileAdapter
+                = new QQmlProfilerAdapter(this, &(enginePrivate->typeLoader));
+        addEngineProfiler(compileAdapter, engine);
     }
     QV4ProfilerAdapter *v4Adapter = new QV4ProfilerAdapter(this, QV8Engine::getV4(engine->handle()));
     addEngineProfiler(v4Adapter, engine);
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index a26c80e093..57121e5460 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -317,7 +317,6 @@ void Document::removeScriptPragmas(QString &script)
 Document::Document(bool debugMode)
     : jsModule(debugMode)
     , program(0)
-    , indexOfRootObject(0)
     , jsGenerator(&jsModule)
 {
 }
@@ -421,7 +420,10 @@ bool IRBuilder::generateFromQml(const QString &code, const QString &url, Documen
 
     QQmlJS::AST::UiObjectDefinition *rootObject = QQmlJS::AST::cast<QQmlJS::AST::UiObjectDefinition*>(program->members->member);
     Q_ASSERT(rootObject);
-    defineQMLObject(&output->indexOfRootObject, rootObject);
+    int rootObjectIndex = -1;
+    if (defineQMLObject(&rootObjectIndex, rootObject)) {
+        Q_ASSERT(rootObjectIndex == 0);
+    }
 
     qSwap(_imports, output->imports);
     qSwap(_pragmas, output->pragmas);
@@ -1468,7 +1470,6 @@ QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, const QV4:
     qmlUnit->nImports = output.imports.count();
     qmlUnit->offsetToObjects = unitSize + importSize;
     qmlUnit->nObjects = output.objects.count();
-    qmlUnit->indexOfRootObject = output.indexOfRootObject;
     qmlUnit->offsetToStringTable = totalSize - output.jsGenerator.stringTable.sizeOfTableAndData();
     qmlUnit->stringTableSize = output.jsGenerator.stringTable.stringCount();
 
@@ -2216,8 +2217,6 @@ void IRLoader::load()
         output->pragmas << p;
     }
 
-    output->indexOfRootObject = unit->indexOfRootObject;
-
     for (uint i = 0; i < unit->nObjects; ++i) {
         const QV4::CompiledData::Object *serializedObject = unit->objectAt(i);
         QmlIR::Object *object = loadObject(serializedObject);
diff --git a/src/qml/compiler/qqmlirbuilder_p.h b/src/qml/compiler/qqmlirbuilder_p.h
index 4c29e0b9f5..a5b4815745 100644
--- a/src/qml/compiler/qqmlirbuilder_p.h
+++ b/src/qml/compiler/qqmlirbuilder_p.h
@@ -457,7 +457,6 @@ struct Q_QML_PRIVATE_EXPORT Document
     QList<const QV4::CompiledData::Import *> imports;
     QList<Pragma*> pragmas;
     QQmlJS::AST::UiProgram *program;
-    int indexOfRootObject;
     QVector<Object*> objects;
     QV4::Compiler::JSUnitGenerator jsGenerator;
 
diff --git a/src/qml/compiler/qqmlpropertycachecreator_p.h b/src/qml/compiler/qqmlpropertycachecreator_p.h
index b33deac045..5d6a5c177a 100644
--- a/src/qml/compiler/qqmlpropertycachecreator_p.h
+++ b/src/qml/compiler/qqmlpropertycachecreator_p.h
@@ -108,7 +108,7 @@ template <typename ObjectContainer>
 inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::buildMetaObjects()
 {
     QQmlBindingInstantiationContext context;
-    return buildMetaObjectRecursively(objectContainer->rootObjectIndex(), context);
+    return buildMetaObjectRecursively(/*root object*/0, context);
 }
 
 template <typename ObjectContainer>
@@ -278,7 +278,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
 
     QByteArray newClassName;
 
-    if (objectIndex == objectContainer->rootObjectIndex()) {
+    if (objectIndex == /*root object*/0) {
         const QString path = objectContainer->url().path();
         int lastSlash = path.lastIndexOf(QLatin1Char('/'));
         if (lastSlash > -1) {
@@ -576,7 +576,9 @@ inline QQmlPropertyCacheAliasCreator<ObjectContainer>::QQmlPropertyCacheAliasCre
 template <typename ObjectContainer>
 inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasPropertiesToMetaObjects()
 {
-    for (int i = 0; i < objectContainer->objectCount(); ++i) {
+    // skip the root object (index 0) as that one does not have a first object index originating
+    // from a binding.
+    for (int i = 1; i < objectContainer->objectCount(); ++i) {
         const CompiledObject &component = *objectContainer->objectAt(i);
         if (!(component.flags & QV4::CompiledData::Object::IsComponent))
             continue;
@@ -585,7 +587,7 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasPropertie
         appendAliasPropertiesInMetaObjectsWithinComponent(component, rootBinding->value.objectIndex);
     }
 
-    const int rootObjectIndex = objectContainer->rootObjectIndex();
+    const int rootObjectIndex = 0;
     appendAliasPropertiesInMetaObjectsWithinComponent(*objectContainer->objectAt(rootObjectIndex), rootObjectIndex);
 }
 
@@ -648,7 +650,7 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::collectObjectsWithAl
         objectsWithAliases->append(objectIndex);
 
     // Stop at Component boundary
-    if (object.flags & QV4::CompiledData::Object::IsComponent && objectIndex != objectContainer->rootObjectIndex())
+    if (object.flags & QV4::CompiledData::Object::IsComponent && objectIndex != /*root object*/0)
         return;
 
     auto binding = object.bindingsBegin();
diff --git a/src/qml/compiler/qqmlpropertyvalidator.cpp b/src/qml/compiler/qqmlpropertyvalidator.cpp
index 4ac7aad553..7ea89b378d 100644
--- a/src/qml/compiler/qqmlpropertyvalidator.cpp
+++ b/src/qml/compiler/qqmlpropertyvalidator.cpp
@@ -58,7 +58,7 @@ QQmlPropertyValidator::QQmlPropertyValidator(QQmlEnginePrivate *enginePrivate, c
 
 QVector<QQmlCompileError> QQmlPropertyValidator::validate()
 {
-    return validateObject(qmlUnit->indexOfRootObject, /*instantiatingBinding*/0);
+    return validateObject(/*root object*/0, /*instantiatingBinding*/0);
 }
 
 typedef QVarLengthArray<const QV4::CompiledData::Binding *, 8> GroupPropertyVector;
@@ -94,16 +94,6 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
     if (!propertyCache)
         return QVector<QQmlCompileError>();
 
-    QStringList deferredPropertyNames;
-    {
-        const QMetaObject *mo = propertyCache->firstCppMetaObject();
-        const int namesIndex = mo->indexOfClassInfo("DeferredPropertyNames");
-        if (namesIndex != -1) {
-            QMetaClassInfo classInfo = mo->classInfo(namesIndex);
-            deferredPropertyNames = QString::fromUtf8(classInfo.value()).split(QLatin1Char(','));
-        }
-    }
-
     QQmlCustomParser *customParser = 0;
     if (auto typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex)) {
         if (typeRef->type.isValid())
diff --git a/src/qml/compiler/qqmltypecompiler.cpp b/src/qml/compiler/qqmltypecompiler.cpp
index 9058a6c78f..697690984f 100644
--- a/src/qml/compiler/qqmltypecompiler.cpp
+++ b/src/qml/compiler/qqmltypecompiler.cpp
@@ -228,15 +228,10 @@ QVector<QmlIR::Object *> *QQmlTypeCompiler::qmlObjects() const
     return &document->objects;
 }
 
-int QQmlTypeCompiler::rootObjectIndex() const
-{
-    return document->indexOfRootObject;
-}
-
 void QQmlTypeCompiler::setPropertyCaches(QQmlPropertyCacheVector &&caches)
 {
     m_propertyCaches = std::move(caches);
-    Q_ASSERT(m_propertyCaches.count() >= document->indexOfRootObject);
+    Q_ASSERT(m_propertyCaches.count() > 0);
 }
 
 const QQmlPropertyCacheVector *QQmlTypeCompiler::propertyCaches() const
@@ -703,7 +698,7 @@ QQmlCustomParserScriptIndexer::QQmlCustomParserScriptIndexer(QQmlTypeCompiler *t
 
 void QQmlCustomParserScriptIndexer::annotateBindingsWithScriptStrings()
 {
-    scanObjectRecursively(compiler->rootObjectIndex());
+    scanObjectRecursively(/*root object*/0);
 }
 
 void QQmlCustomParserScriptIndexer::scanObjectRecursively(int objectIndex, bool annotateScriptBindings)
@@ -798,7 +793,6 @@ QQmlComponentAndAliasResolver::QQmlComponentAndAliasResolver(QQmlTypeCompiler *t
     , enginePrivate(typeCompiler->enginePrivate())
     , pool(typeCompiler->memoryPool())
     , qmlObjects(typeCompiler->qmlObjects())
-    , indexOfRootObject(typeCompiler->rootObjectIndex())
     , resolvedTypes(&typeCompiler->resolvedTypes)
     , propertyCaches(std::move(typeCompiler->takePropertyCaches()))
 {
@@ -936,9 +930,9 @@ bool QQmlComponentAndAliasResolver::resolve()
         if (rootBinding->next || rootBinding->type != QV4::CompiledData::Binding::Type_Object)
             COMPILE_EXCEPTION(obj, tr("Invalid component body specification"));
 
-        // We are going to collect ids/aliases and resolve them for the root object as a separate
+        // For the root object, we are going to collect ids/aliases and resolve them for as a separate
         // last pass.
-        if (i != indexOfRootObject)
+        if (i != 0)
             componentRoots.append(i);
 
     }
@@ -964,12 +958,12 @@ bool QQmlComponentAndAliasResolver::resolve()
     _idToObjectIndex.clear();
     _objectsWithAliases.clear();
 
-    collectIdsAndAliases(indexOfRootObject);
+    collectIdsAndAliases(/*root object*/0);
 
-    QmlIR::Object *rootComponent = qmlObjects->at(indexOfRootObject);
+    QmlIR::Object *rootComponent = qmlObjects->at(/*root object*/0);
     rootComponent->namedObjectsInComponent.allocate(pool, _idToObjectIndex);
 
-    if (!resolveAliases(indexOfRootObject))
+    if (!resolveAliases(/*root object*/0))
         return false;
 
     // Implicit component insertion may have added objects and thus we also need
@@ -997,7 +991,7 @@ bool QQmlComponentAndAliasResolver::collectIdsAndAliases(int objectIndex)
         _objectsWithAliases.append(objectIndex);
 
     // Stop at Component boundary
-    if (obj->flags & QV4::CompiledData::Object::IsComponent && objectIndex != compiler->rootObjectIndex())
+    if (obj->flags & QV4::CompiledData::Object::IsComponent && objectIndex != /*root object*/0)
         return true;
 
     for (const QmlIR::Binding *binding = obj->firstBinding(); binding; binding = binding->next) {
@@ -1188,7 +1182,7 @@ QQmlDeferredAndCustomParserBindingScanner::QQmlDeferredAndCustomParserBindingSca
 
 bool QQmlDeferredAndCustomParserBindingScanner::scanObject()
 {
-    return scanObject(compiler->rootObjectIndex());
+    return scanObject(/*root object*/0);
 }
 
 bool QQmlDeferredAndCustomParserBindingScanner::scanObject(int objectIndex)
@@ -1274,7 +1268,7 @@ bool QQmlDeferredAndCustomParserBindingScanner::scanObject(int objectIndex)
             _seenObjectWithId |= seenSubObjectWithId;
         }
 
-        if (!seenSubObjectWithId
+        if (!seenSubObjectWithId && binding->type != QV4::CompiledData::Binding::Type_GroupProperty
             && !deferredPropertyNames.isEmpty() && deferredPropertyNames.contains(name)) {
 
             binding->flags |= QV4::CompiledData::Binding::IsDeferredBinding;
@@ -1314,7 +1308,7 @@ bool QQmlJSCodeGenerator::generateCodeForComponents()
             return false;
     }
 
-    return compileComponent(compiler->rootObjectIndex());
+    return compileComponent(/*root object*/0);
 }
 
 bool QQmlJSCodeGenerator::compileComponent(int contextObject)
diff --git a/src/qml/compiler/qqmltypecompiler_p.h b/src/qml/compiler/qqmltypecompiler_p.h
index 76aa422fc5..4878a90641 100644
--- a/src/qml/compiler/qqmltypecompiler_p.h
+++ b/src/qml/compiler/qqmltypecompiler_p.h
@@ -119,7 +119,6 @@ public:
     QQmlEnginePrivate *enginePrivate() const { return engine; }
     const QQmlImports *imports() const;
     QVector<QmlIR::Object *> *qmlObjects() const;
-    int rootObjectIndex() const;
     void setPropertyCaches(QQmlPropertyCacheVector &&caches);
     const QQmlPropertyCacheVector *propertyCaches() const;
     QQmlPropertyCacheVector &&takePropertyCaches();
@@ -282,7 +281,6 @@ protected:
     QQmlJS::MemoryPool *pool;
 
     QVector<QmlIR::Object*> *qmlObjects;
-    const int indexOfRootObject;
 
     // indices of the objects that are actually Component {}
     QVector<quint32> componentRoots;
diff --git a/src/qml/compiler/qv4compileddata.cpp b/src/qml/compiler/qv4compileddata.cpp
index 6b20557076..d0b2e4f08a 100644
--- a/src/qml/compiler/qv4compileddata.cpp
+++ b/src/qml/compiler/qv4compileddata.cpp
@@ -46,6 +46,7 @@
 #include <private/qv4objectproto_p.h>
 #include <private/qv4lookup_p.h>
 #include <private/qv4regexpobject_p.h>
+#include <private/qv4regexp_p.h>
 #include <private/qqmlpropertycache_p.h>
 #include <private/qqmltypeloader_p.h>
 #include <private/qqmlengine_p.h>
@@ -136,15 +137,16 @@ QV4::Function *CompilationUnit::linkToEngine(ExecutionEngine *engine)
     memset(runtimeRegularExpressions, 0, data->regexpTableSize * sizeof(QV4::Value));
     for (uint i = 0; i < data->regexpTableSize; ++i) {
         const CompiledData::RegExp *re = data->regexpAt(i);
-        int flags = 0;
+        bool global = false;
+        bool multiline = false;
+        bool ignoreCase = false;
         if (re->flags & CompiledData::RegExp::RegExp_Global)
-            flags |= IR::RegExp::RegExp_Global;
+            global = true;
         if (re->flags & CompiledData::RegExp::RegExp_IgnoreCase)
-            flags |= IR::RegExp::RegExp_IgnoreCase;
+            ignoreCase = true;
         if (re->flags & CompiledData::RegExp::RegExp_Multiline)
-            flags |= IR::RegExp::RegExp_Multiline;
-        QV4::Heap::RegExpObject *ro = engine->newRegExpObject(data->stringAt(re->stringIndex), flags);
-        runtimeRegularExpressions[i] = ro;
+            multiline = true;
+        runtimeRegularExpressions[i] = QV4::RegExp::create(engine, data->stringAt(re->stringIndex), ignoreCase, multiline, global);
     }
 
     if (data->lookupTableSize) {
@@ -211,7 +213,7 @@ void CompilationUnit::unlink()
         engine->compilationUnits.erase(engine->compilationUnits.find(this));
 
     if (isRegisteredWithEngine) {
-        Q_ASSERT(data && quint32(propertyCaches.count()) > data->indexOfRootObject && propertyCaches.at(data->indexOfRootObject));
+        Q_ASSERT(data && propertyCaches.count() > 0 && propertyCaches.at(/*root object*/0));
         if (qmlEngine)
             qmlEngine->unregisterInternalCompositeType(this);
         QQmlMetaType::unregisterInternalCompositeType(this);
@@ -287,11 +289,11 @@ void CompilationUnit::finalizeCompositeType(QQmlEnginePrivate *qmlEngine)
     this->qmlEngine = qmlEngine;
 
     // Add to type registry of composites
-    if (propertyCaches.needsVMEMetaObject(data->indexOfRootObject)) {
+    if (propertyCaches.needsVMEMetaObject(/*root object*/0)) {
         QQmlMetaType::registerInternalCompositeType(this);
         qmlEngine->registerInternalCompositeType(this);
     } else {
-        const QV4::CompiledData::Object *obj = objectAt(data->indexOfRootObject);
+        const QV4::CompiledData::Object *obj = objectAt(/*root object*/0);
         auto *typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex);
         Q_ASSERT(typeRef);
         if (typeRef->compilationUnit) {
@@ -730,8 +732,6 @@ void ResolvedTypeReference::doDynamicTypeCheck()
     isFullyDynamicType = qtTypeInherits<QQmlPropertyMap>(mo);
 }
 
-#if defined(QT_BUILD_INTERNAL)
-
 static QByteArray ownLibraryChecksum()
 {
     static QByteArray libraryChecksum;
@@ -739,7 +739,10 @@ static QByteArray ownLibraryChecksum()
     if (checksumInitialized)
         return libraryChecksum;
     checksumInitialized = true;
-#if !defined(QT_NO_DYNAMIC_CAST) && QT_CONFIG(dlopen)
+#if defined(QT_BUILD_INTERNAL) && !defined(QT_NO_DYNAMIC_CAST) && QT_CONFIG(dlopen)
+    // This is a bit of a hack to make development easier. When hacking on the code generator
+    // the cache files may end up being re-used. To avoid that we also add the checksum of
+    // the QtQml library.
     Dl_info libInfo;
     if (dladdr(reinterpret_cast<const void *>(&ownLibraryChecksum), &libInfo) != 0) {
         QFile library(QFile::decodeName(libInfo.dli_fname));
@@ -749,14 +752,14 @@ static QByteArray ownLibraryChecksum()
             libraryChecksum = hash.result();
         }
     }
+#elif defined(QML_COMPILE_HASH)
+    libraryChecksum = QByteArray(QT_STRINGIFY(QML_COMPILE_HASH));
 #else
     // Not implemented.
 #endif
     return libraryChecksum;
 }
 
-#endif
-
 bool ResolvedTypeReferenceMap::addToHash(QCryptographicHash *hash, QQmlEngine *engine) const
 {
     for (auto it = constBegin(), end = constEnd(); it != end; ++it) {
@@ -764,12 +767,7 @@ bool ResolvedTypeReferenceMap::addToHash(QCryptographicHash *hash, QQmlEngine *e
             return false;
     }
 
-    // This is a bit of a hack to make development easier. When hacking on the code generator
-    // the cache files may end up being re-used. To avoid that we also add the checksum of
-    // the QtQml library.
-#if defined(QT_BUILD_INTERNAL)
     hash->addData(ownLibraryChecksum());
-#endif
 
     return true;
 }
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index cc4a96d5c0..ce54e4fae4 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -71,7 +71,7 @@
 QT_BEGIN_NAMESPACE
 
 // Bump this whenever the compiler data structures change in an incompatible way.
-#define QV4_DATA_STRUCTURE_VERSION 0x11
+#define QV4_DATA_STRUCTURE_VERSION 0x13
 
 class QIODevice;
 class QQmlPropertyCache;
@@ -115,10 +115,6 @@ struct TableIterator
     bool operator!=(const TableIterator &rhs) const { return index != rhs.index; }
 };
 
-#if defined(Q_CC_MSVC) || defined(Q_CC_GNU)
-#pragma pack(push, 1)
-#endif
-
 struct Location
 {
     union {
@@ -134,6 +130,7 @@ struct Location
                (line == other.line && column < other.column);
     }
 };
+static_assert(sizeof(Location) == 4, "Location structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct RegExp
 {
@@ -150,6 +147,7 @@ struct RegExp
 
     RegExp() : _dummy(0) { }
 };
+static_assert(sizeof(RegExp) == 4, "RegExp structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Lookup
 {
@@ -169,6 +167,7 @@ struct Lookup
 
     Lookup() : _dummy(0) { }
 };
+static_assert(sizeof(Lookup) == 4, "Lookup structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct JSClassMember
 {
@@ -180,6 +179,7 @@ struct JSClassMember
 
     JSClassMember() : _dummy(0) { }
 };
+static_assert(sizeof(JSClassMember) == 4, "JSClassMember structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct JSClass
 {
@@ -188,6 +188,7 @@ struct JSClass
 
     static int calculateSize(int nMembers) { return (sizeof(JSClass) + nMembers * sizeof(JSClassMember) + 7) & ~7; }
 };
+static_assert(sizeof(JSClass) == 4, "JSClass structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct String
 {
@@ -198,6 +199,7 @@ struct String
         return (sizeof(String) + str.length() * sizeof(quint16) + 7) & ~0x7;
     }
 };
+static_assert(sizeof(String) == 4, "String structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 // Function is aligned on an 8-byte boundary to make sure there are no bus errors or penalties
 // for unaligned access. The ordering of the fields is also from largest to smallest.
@@ -241,6 +243,8 @@ struct Function
 
     // Keep all unaligned data at the end
     quint8 flags;
+    quint8 padding1;
+    quint16_le padding2;
 
     const quint32_le *formalsTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + formalsOffset); }
     const quint32_le *localsTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + localsOffset); }
@@ -259,6 +263,7 @@ struct Function
         return (sizeof(Function) + (nFormals + nLocals + nInnerfunctions + nIdObjectDependencies + 2 * nPropertyDependencies) * sizeof(quint32) + 7) & ~0x7;
     }
 };
+static_assert(sizeof(Function) == 72, "Function structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 // Qml data structures
 
@@ -266,6 +271,7 @@ struct Q_QML_EXPORT TranslationData {
     quint32_le commentIndex;
     qint32_le number;
 };
+static_assert(sizeof(TranslationData) == 8, "TranslationData structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Q_QML_PRIVATE_EXPORT Binding
 {
@@ -312,6 +318,8 @@ struct Q_QML_PRIVATE_EXPORT Binding
     Location location;
     Location valueLocation;
 
+    quint32_le padding;
+
     bool isValueBinding() const
     {
         if (type == Type_AttachedProperty
@@ -391,6 +399,8 @@ struct Q_QML_PRIVATE_EXPORT Binding
 
 };
 
+static_assert(sizeof(Binding) == 32, "Binding structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
 struct EnumValue
 {
     quint32_le nameIndex;
@@ -428,6 +438,7 @@ struct Parameter
     quint32_le customTypeNameIndex;
     Location location;
 };
+static_assert(sizeof(Parameter) == 16, "Parameter structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Signal
 {
@@ -452,6 +463,7 @@ struct Signal
     int parameterCount() const { return nParameters; }
     // ---
 };
+static_assert(sizeof(Signal) == 12, "Signal structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Property
 {
@@ -472,6 +484,7 @@ struct Property
     quint32_le customTypeNameIndex; // If type >= Custom
     Location location;
 };
+static_assert(sizeof(Property) == 16, "Property structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Alias {
     enum Flags : unsigned int {
@@ -501,6 +514,7 @@ struct Alias {
         return encodedMetaPropertyIndex == -1;
     }
 };
+static_assert(sizeof(Alias) == 20, "Alias structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Object
 {
@@ -623,6 +637,7 @@ struct Object
     int namedObjectsInComponentCount() const { return nNamedObjectsInComponent; }
     // ---
 };
+static_assert(sizeof(Object) == 80, "Object structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Import
 {
@@ -643,6 +658,7 @@ struct Import
 
     Import() { type = 0; uriIndex = 0; qualifierIndex = 0; majorVersion = 0; minorVersion = 0; }
 };
+static_assert(sizeof(Import) == 24, "Import structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 static const char magic_str[] = "qv4cdata";
 
@@ -693,7 +709,6 @@ struct Unit
     quint32_le offsetToImports;
     quint32_le nObjects;
     quint32_le offsetToObjects;
-    quint32_le indexOfRootObject;
 
     const Import *importAt(int idx) const {
         return reinterpret_cast<const Import*>((reinterpret_cast<const char *>(this)) + offsetToImports + idx * sizeof(Import));
@@ -759,9 +774,7 @@ struct Unit
     }
 };
 
-#if defined(Q_CC_MSVC) || defined(Q_CC_GNU)
-#pragma pack(pop)
-#endif
+static_assert(sizeof(Unit) == 144, "Unit structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct TypeReference
 {
@@ -881,7 +894,7 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public CompilationUnitBase, public
 
     // QML specific fields
     QQmlPropertyCacheVector propertyCaches;
-    QQmlPropertyCache *rootPropertyCache() const { return propertyCaches.at(data->indexOfRootObject); }
+    QQmlPropertyCache *rootPropertyCache() const { return propertyCaches.at(/*root object*/0); }
 
     QQmlRefPointer<QQmlTypeNameCache> typeNameCache;
 
@@ -918,7 +931,6 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public CompilationUnitBase, public
     // --- interface for QQmlPropertyCacheCreator
     typedef Object CompiledObject;
     int objectCount() const { return data->nObjects; }
-    int rootObjectIndex() const { return data->indexOfRootObject; }
     const Object *objectAt(int index) const { return data->objectAt(index); }
     QString stringAt(int index) const { return data->stringAt(index); }
 
diff --git a/src/qml/compiler/qv4compiler.cpp b/src/qml/compiler/qv4compiler.cpp
index 35825587b1..f02ee728c9 100644
--- a/src/qml/compiler/qv4compiler.cpp
+++ b/src/qml/compiler/qv4compiler.cpp
@@ -434,7 +434,6 @@ QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Comp
     unit.offsetToImports = 0;
     unit.nObjects = 0;
     unit.offsetToObjects = 0;
-    unit.indexOfRootObject = 0;
 
     unit.unitSize = nextOffset;
 
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 8ca6b03950..a5fc37b91b 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -142,10 +142,6 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     , m_engineId(engineSerial.fetchAndAddOrdered(1))
     , regExpCache(0)
     , m_multiplyWrappedQObjects(0)
-#ifndef QT_NO_QML_DEBUGGER
-    , m_debugger(0)
-    , m_profiler(0)
-#endif
 {
     memoryManager = new QV4::MemoryManager(this);
 
@@ -501,12 +497,6 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
 
 ExecutionEngine::~ExecutionEngine()
 {
-#ifndef QT_NO_QML_DEBUGGER
-    delete m_debugger;
-    m_debugger = 0;
-    delete m_profiler;
-    m_profiler = 0;
-#endif
     delete m_multiplyWrappedQObjects;
     m_multiplyWrappedQObjects = 0;
     delete identifierTable;
@@ -534,13 +524,13 @@ ExecutionEngine::~ExecutionEngine()
 void ExecutionEngine::setDebugger(Debugging::Debugger *debugger)
 {
     Q_ASSERT(!m_debugger);
-    m_debugger = debugger;
+    m_debugger.reset(debugger);
 }
 
 void ExecutionEngine::setProfiler(Profiling::Profiler *profiler)
 {
     Q_ASSERT(!m_profiler);
-    m_profiler = profiler;
+    m_profiler.reset(profiler);
 }
 #endif // QT_NO_QML_DEBUGGER
 
@@ -698,21 +688,17 @@ Heap::DateObject *ExecutionEngine::newDateObjectFromTime(const QTime &t)
 Heap::RegExpObject *ExecutionEngine::newRegExpObject(const QString &pattern, int flags)
 {
     bool global = (flags & IR::RegExp::RegExp_Global);
-    bool ignoreCase = false;
-    bool multiline = false;
-    if (flags & IR::RegExp::RegExp_IgnoreCase)
-        ignoreCase = true;
-    if (flags & IR::RegExp::RegExp_Multiline)
-        multiline = true;
+    bool ignoreCase = (flags & IR::RegExp::RegExp_IgnoreCase);
+    bool multiline = (flags & IR::RegExp::RegExp_Multiline);
 
     Scope scope(this);
-    Scoped<RegExp> re(scope, RegExp::create(this, pattern, ignoreCase, multiline));
-    return newRegExpObject(re, global);
+    Scoped<RegExp> re(scope, RegExp::create(this, pattern, ignoreCase, multiline, global));
+    return newRegExpObject(re);
 }
 
-Heap::RegExpObject *ExecutionEngine::newRegExpObject(RegExp *re, bool global)
+Heap::RegExpObject *ExecutionEngine::newRegExpObject(RegExp *re)
 {
-    return memoryManager->allocObject<RegExpObject>(re, global);
+    return memoryManager->allocObject<RegExpObject>(re);
 }
 
 Heap::RegExpObject *ExecutionEngine::newRegExpObject(const QRegExp &re)
diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index 16a043dda5..3b4212020d 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -349,8 +349,8 @@ public:
     void setDebugger(Debugging::Debugger *) {}
     void setProfiler(Profiling::Profiler *) {}
 #else
-    QV4::Debugging::Debugger *debugger() const { return m_debugger; }
-    QV4::Profiling::Profiler *profiler() const { return m_profiler; }
+    QV4::Debugging::Debugger *debugger() const { return m_debugger.data(); }
+    QV4::Profiling::Profiler *profiler() const { return m_profiler.data(); }
 
     void setDebugger(Debugging::Debugger *debugger);
     void setProfiler(Profiling::Profiler *profiler);
@@ -387,7 +387,7 @@ public:
     Heap::DateObject *newDateObjectFromTime(const QTime &t);
 
     Heap::RegExpObject *newRegExpObject(const QString &pattern, int flags);
-    Heap::RegExpObject *newRegExpObject(RegExp *re, bool global);
+    Heap::RegExpObject *newRegExpObject(RegExp *re);
     Heap::RegExpObject *newRegExpObject(const QRegExp &re);
 
     Heap::Object *newErrorObject(const Value &value);
@@ -458,8 +458,8 @@ private:
     void failStackLimitCheck(Scope &scope);
 
 #ifndef QT_NO_QML_DEBUGGER
-    QV4::Debugging::Debugger *m_debugger;
-    QV4::Profiling::Profiler *m_profiler;
+    QScopedPointer<QV4::Debugging::Debugger> m_debugger;
+    QScopedPointer<QV4::Profiling::Profiler> m_profiler;
 #endif
 };
 
diff --git a/src/qml/jsruntime/qv4mathobject.cpp b/src/qml/jsruntime/qv4mathobject.cpp
index 6fd1509d77..46230b5bc1 100644
--- a/src/qml/jsruntime/qv4mathobject.cpp
+++ b/src/qml/jsruntime/qv4mathobject.cpp
@@ -46,6 +46,7 @@
 #include <QtCore/private/qnumeric_p.h>
 #include <QtCore/qthreadstorage.h>
 
+#include <math.h>
 #include <cmath>
 
 using namespace QV4;
diff --git a/src/qml/jsruntime/qv4qmlcontext.cpp b/src/qml/jsruntime/qv4qmlcontext.cpp
index c483fdb7e7..8b9ef149d6 100644
--- a/src/qml/jsruntime/qv4qmlcontext.cpp
+++ b/src/qml/jsruntime/qv4qmlcontext.cpp
@@ -62,20 +62,17 @@ using namespace QV4;
 DEFINE_OBJECT_VTABLE(QQmlContextWrapper);
 DEFINE_MANAGED_VTABLE(QmlContext);
 
-void Heap::QQmlContextWrapper::init(QQmlContextData *context, QObject *scopeObject, bool ownsContext)
+void Heap::QQmlContextWrapper::init(QQmlContextData *context, QObject *scopeObject)
 {
     Object::init();
     readOnly = true;
-    this->ownsContext = ownsContext;
     isNullWrapper = false;
-    this->context = new QQmlGuardedContextData(context);
+    this->context = new QQmlContextDataRef(context);
     this->scopeObject.init(scopeObject);
 }
 
 void Heap::QQmlContextWrapper::destroy()
 {
-    if (*context && ownsContext)
-        (*context)->destroy();
     delete context;
     scopeObject.destroy();
     Object::destroy();
@@ -318,7 +315,7 @@ Heap::QmlContext *QmlContext::createWorkerContext(ExecutionContext *parent, cons
     context->isInternal = true;
     context->isJSContext = true;
 
-    Scoped<QQmlContextWrapper> qml(scope, scope.engine->memoryManager->allocObject<QQmlContextWrapper>(context, (QObject*)0, true));
+    Scoped<QQmlContextWrapper> qml(scope, scope.engine->memoryManager->allocObject<QQmlContextWrapper>(context, (QObject*)0));
     qml->d()->isNullWrapper = true;
 
     qml->setReadOnly(false);
diff --git a/src/qml/jsruntime/qv4qmlcontext_p.h b/src/qml/jsruntime/qv4qmlcontext_p.h
index 2f1dbabaf2..48c9ee2c36 100644
--- a/src/qml/jsruntime/qv4qmlcontext_p.h
+++ b/src/qml/jsruntime/qv4qmlcontext_p.h
@@ -67,13 +67,12 @@ struct QQmlContextWrapper;
 namespace Heap {
 
 struct QQmlContextWrapper : Object {
-    void init(QQmlContextData *context, QObject *scopeObject, bool ownsContext = false);
+    void init(QQmlContextData *context, QObject *scopeObject);
     void destroy();
     bool readOnly;
-    bool ownsContext;
     bool isNullWrapper;
 
-    QQmlGuardedContextData *context;
+    QQmlContextDataRef *context;
     QQmlQPointer<QObject> scopeObject;
 };
 
@@ -93,10 +92,6 @@ struct Q_QML_EXPORT QQmlContextWrapper : Object
     V4_OBJECT2(QQmlContextWrapper, Object)
     V4_NEEDS_DESTROY
 
-    void takeContextOwnership() {
-        d()->ownsContext = true;
-    }
-
     inline QObject *getScopeObject() const { return d()->scopeObject; }
     inline QQmlContextData *getContext() const { return *d()->context; }
 
@@ -119,10 +114,6 @@ struct Q_QML_EXPORT QmlContext : public ExecutionContext
     QQmlContextData *qmlContext() const {
         return *d()->qml->context;
     }
-
-    void takeContextOwnership() {
-        d()->qml->ownsContext = true;
-    }
 };
 
 }
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index 72ad0ce7b7..fb3aa47d1b 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -1040,8 +1040,12 @@ void QObjectWrapper::destroyObject(bool lastCall)
         QQmlData *ddata = QQmlData::get(h->object(), false);
         if (ddata) {
             if (!h->object()->parent() && !ddata->indestructible) {
-                if (ddata && ddata->ownContext && ddata->context)
-                    ddata->context->emitDestruction();
+                if (ddata && ddata->ownContext) {
+                    Q_ASSERT(ddata->ownContext == ddata->context);
+                    ddata->ownContext->emitDestruction();
+                    ddata->ownContext = 0;
+                    ddata->context = 0;
+                }
                 // This object is notionally destroyed now
                 ddata->isQueuedForDeletion = true;
                 if (lastCall)
diff --git a/src/qml/jsruntime/qv4regexp.cpp b/src/qml/jsruntime/qv4regexp.cpp
index 6778145ff1..162f0fba57 100644
--- a/src/qml/jsruntime/qv4regexp.cpp
+++ b/src/qml/jsruntime/qv4regexp.cpp
@@ -69,9 +69,9 @@ uint RegExp::match(const QString &string, int start, uint *matchOffsets)
     return JSC::Yarr::interpret(byteCode(), s.characters16(), string.length(), start, matchOffsets);
 }
 
-Heap::RegExp *RegExp::create(ExecutionEngine* engine, const QString& pattern, bool ignoreCase, bool multiline)
+Heap::RegExp *RegExp::create(ExecutionEngine* engine, const QString& pattern, bool ignoreCase, bool multiline, bool global)
 {
-    RegExpCacheKey key(pattern, ignoreCase, multiline);
+    RegExpCacheKey key(pattern, ignoreCase, multiline, global);
 
     RegExpCache *cache = engine->regExpCache;
     if (!cache)
@@ -82,7 +82,7 @@ Heap::RegExp *RegExp::create(ExecutionEngine* engine, const QString& pattern, bo
         return result->d();
 
     Scope scope(engine);
-    Scoped<RegExp> result(scope, engine->memoryManager->alloc<RegExp>(engine, pattern, ignoreCase, multiline));
+    Scoped<RegExp> result(scope, engine->memoryManager->alloc<RegExp>(engine, pattern, ignoreCase, multiline, global));
 
     result->d()->cache = cache;
     cachedValue.set(engine, result);
@@ -90,12 +90,13 @@ Heap::RegExp *RegExp::create(ExecutionEngine* engine, const QString& pattern, bo
     return result->d();
 }
 
-void Heap::RegExp::init(ExecutionEngine* engine, const QString &pattern, bool ignoreCase, bool multiline)
+void Heap::RegExp::init(ExecutionEngine* engine, const QString &pattern, bool ignoreCase, bool multiline, bool global)
 {
     Base::init();
     this->pattern = new QString(pattern);
     this->ignoreCase = ignoreCase;
     this->multiLine = multiline;
+    this->global = global;
 
     const char* error = 0;
     JSC::Yarr::YarrPattern yarrPattern(WTF::String(pattern), ignoreCase, multiline, &error);
diff --git a/src/qml/jsruntime/qv4regexp_p.h b/src/qml/jsruntime/qv4regexp_p.h
index 7ab12fe245..998f6e3da3 100644
--- a/src/qml/jsruntime/qv4regexp_p.h
+++ b/src/qml/jsruntime/qv4regexp_p.h
@@ -76,7 +76,7 @@ struct RegExpCacheKey;
 namespace Heap {
 
 struct RegExp : Base {
-    void init(ExecutionEngine* engine, const QString& pattern, bool ignoreCase, bool multiline);
+    void init(ExecutionEngine* engine, const QString& pattern, bool ignoreCase, bool multiline, bool global);
     void destroy();
 
     QString *pattern;
@@ -88,6 +88,7 @@ struct RegExp : Base {
     int subPatternCount;
     bool ignoreCase;
     bool multiLine;
+    bool global;
 
     int captureCount() const { return subPatternCount + 1; }
 };
@@ -111,8 +112,9 @@ struct RegExp : public Managed
     int subPatternCount() const { return d()->subPatternCount; }
     bool ignoreCase() const { return d()->ignoreCase; }
     bool multiLine() const { return d()->multiLine; }
+    bool global() const { return d()->global; }
 
-    static Heap::RegExp *create(ExecutionEngine* engine, const QString& pattern, bool ignoreCase = false, bool multiline = false);
+    static Heap::RegExp *create(ExecutionEngine* engine, const QString& pattern, bool ignoreCase = false, bool multiline = false, bool global = false);
 
     bool isValid() const { return d()->byteCode; }
 
@@ -125,27 +127,30 @@ struct RegExp : public Managed
 
 struct RegExpCacheKey
 {
-    RegExpCacheKey(const QString &pattern, bool ignoreCase, bool multiLine)
+    RegExpCacheKey(const QString &pattern, bool ignoreCase, bool multiLine, bool global)
         : pattern(pattern)
         , ignoreCase(ignoreCase)
         , multiLine(multiLine)
+        , global(global)
     { }
     explicit inline RegExpCacheKey(const RegExp::Data *re);
 
     bool operator==(const RegExpCacheKey &other) const
-    { return pattern == other.pattern && ignoreCase == other.ignoreCase && multiLine == other.multiLine; }
+    { return pattern == other.pattern && ignoreCase == other.ignoreCase && multiLine == other.multiLine && global == other.global; }
     bool operator!=(const RegExpCacheKey &other) const
     { return !operator==(other); }
 
     QString pattern;
     uint ignoreCase : 1;
     uint multiLine : 1;
+    uint global : 1;
 };
 
 inline RegExpCacheKey::RegExpCacheKey(const RegExp::Data *re)
     : pattern(*re->pattern)
     , ignoreCase(re->ignoreCase)
     , multiLine(re->multiLine)
+    , global(re->global)
 {}
 
 inline uint qHash(const RegExpCacheKey& key, uint seed = 0) Q_DECL_NOTHROW
diff --git a/src/qml/jsruntime/qv4regexpobject.cpp b/src/qml/jsruntime/qv4regexpobject.cpp
index 735951e085..83bfe21c67 100644
--- a/src/qml/jsruntime/qv4regexpobject.cpp
+++ b/src/qml/jsruntime/qv4regexpobject.cpp
@@ -75,15 +75,13 @@ void Heap::RegExpObject::init()
     Scope scope(internalClass->engine);
     Scoped<QV4::RegExpObject> o(scope, this);
     value.set(scope.engine, QV4::RegExp::create(scope.engine, QString(), false, false));
-    global = false;
     o->initProperties();
 }
 
-void Heap::RegExpObject::init(QV4::RegExp *value, bool global)
+void Heap::RegExpObject::init(QV4::RegExp *value)
 {
     Object::init();
     Scope scope(internalClass->engine);
-    this->global = global;
     this->value.set(scope.engine, value->d());
     Scoped<QV4::RegExpObject> o(scope, this);
     o->initProperties();
@@ -95,7 +93,6 @@ void Heap::RegExpObject::init(QV4::RegExp *value, bool global)
 void Heap::RegExpObject::init(const QRegExp &re)
 {
     Object::init();
-    global = false;
 
     // Convert the pattern to a ECMAScript pattern.
     QString pattern = QT_PREPEND_NAMESPACE(qt_regexp_toCanonical)(re.pattern(), re.patternSyntax());
@@ -232,7 +229,7 @@ void RegExpCtor::construct(const Managed *, Scope &scope, CallData *callData)
         }
 
         Scoped<RegExp> regexp(scope, re->value());
-        scope.result = Encode(scope.engine->newRegExpObject(regexp, re->global()));
+        scope.result = Encode(scope.engine->newRegExpObject(regexp));
         return;
     }
 
@@ -268,13 +265,13 @@ void RegExpCtor::construct(const Managed *, Scope &scope, CallData *callData)
         }
     }
 
-    Scoped<RegExp> regexp(scope, RegExp::create(scope.engine, pattern, ignoreCase, multiLine));
+    Scoped<RegExp> regexp(scope, RegExp::create(scope.engine, pattern, ignoreCase, multiLine, global));
     if (!regexp->isValid()) {
         scope.result = scope.engine->throwSyntaxError(QStringLiteral("Invalid regular expression"));
         return;
     }
 
-    scope.result = Encode(scope.engine->newRegExpObject(regexp, global));
+    scope.result = Encode(scope.engine->newRegExpObject(regexp));
 }
 
 void RegExpCtor::call(const Managed *that, Scope &scope, CallData *callData)
@@ -410,8 +407,6 @@ void RegExpPrototype::method_compile(const BuiltinFunction *, Scope &scope, Call
     Scoped<RegExpObject> re(scope, scope.result.asReturnedValue());
 
     r->d()->value.set(scope.engine, re->value());
-    r->d()->global = re->global();
-    RETURN_UNDEFINED();
 }
 
 template <int index>
diff --git a/src/qml/jsruntime/qv4regexpobject_p.h b/src/qml/jsruntime/qv4regexpobject_p.h
index 6f54a4ab92..cb2bcbab2d 100644
--- a/src/qml/jsruntime/qv4regexpobject_p.h
+++ b/src/qml/jsruntime/qv4regexpobject_p.h
@@ -60,6 +60,7 @@
 #include "qv4managed_p.h"
 #include "qv4property_p.h"
 #include "qv4objectiterator_p.h"
+#include "qv4regexp_p.h"
 
 #include <QtCore/QString>
 #include <QtCore/QHash>
@@ -74,14 +75,13 @@ namespace QV4 {
 namespace Heap {
 
 #define RegExpObjectMembers(class, Member) \
-    Member(class, Pointer, RegExp *, value) \
-    Member(class, NoMark, bool, global)
+    Member(class, Pointer, RegExp *, value)
 
 DECLARE_HEAP_OBJECT(RegExpObject, Object) {
     DECLARE_MARK_TABLE(RegExpObject);
 
     void init();
-    void init(QV4::RegExp *value, bool global);
+    void init(QV4::RegExp *value);
     void init(const QRegExp &re);
 };
 
@@ -124,7 +124,7 @@ struct RegExpObject: Object {
     };
 
     Heap::RegExp *value() const { return d()->value; }
-    bool global() const { return d()->global; }
+    bool global() const { return d()->value->global; }
 
     void initProperties();
 
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index 9737a18812..4b952bcbbc 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -51,6 +51,8 @@
 #include "qv4lookup_p.h"
 #include "qv4function_p.h"
 #include "qv4numberobject_p.h"
+#include "qv4regexp_p.h"
+#include "qv4regexpobject_p.h"
 #include "private/qlocale_tools_p.h"
 #include "qv4scopedvalue_p.h"
 #include <private/qv4qmlcontext_p.h>
@@ -1477,7 +1479,10 @@ ReturnedValue Runtime::method_getQmlContext(NoThrowEngine *engine)
 
 ReturnedValue Runtime::method_regexpLiteral(ExecutionEngine *engine, int id)
 {
-    return static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeRegularExpressions[id].asReturnedValue();
+    Heap::RegExpObject *ro = engine->newRegExpObject(
+            static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)
+                    ->runtimeRegularExpressions[id].as<RegExp>());
+    return ro->asReturnedValue();
 }
 
 ReturnedValue Runtime::method_getQmlQObjectProperty(ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired)
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index 81f5c3566c..7c65c97d73 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -551,7 +551,7 @@ void StringPrototype::method_replace(const BuiltinFunction *, Scope &scope, Call
                 break;
             }
             nMatchOffsets += re->captureCount() * 2;
-            if (!regExp->d()->global)
+            if (!regExp->global())
                 break;
             offset = qMax(offset + 1, matchOffsets[oldSize + 1]);
         }
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index 7293630924..5749d0aef3 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -50,6 +50,8 @@
 #include <private/qv4math_p.h>
 #include <private/qv4scopedvalue_p.h>
 #include <private/qv4lookup_p.h>
+#include <private/qv4regexp_p.h>
+#include <private/qv4regexpobject_p.h>
 #include <private/qv4string_p.h>
 #include <iostream>
 
@@ -457,7 +459,10 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code)
 
     MOTH_BEGIN_INSTR(LoadRegExp)
 //        TRACE(value, "%s", instr.value.toString(context)->toQString().toUtf8().constData());
-        VALUE(instr.result) = static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeRegularExpressions[instr.regExpId];
+        Heap::RegExpObject *ro = engine->newRegExpObject(
+                static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)
+                        ->runtimeRegularExpressions[instr.regExpId].as<RegExp>());
+        VALUE(instr.result) = ro;
     MOTH_END_INSTR(LoadRegExp)
 
     MOTH_BEGIN_INSTR(LoadClosure)
diff --git a/src/qml/qml.pro b/src/qml/qml.pro
index be3956bb61..e9d7dcbd2d 100644
--- a/src/qml/qml.pro
+++ b/src/qml/qml.pro
@@ -16,6 +16,19 @@ gcc:isEqual(QT_ARCH, "mips"): QMAKE_CXXFLAGS += -fno-reorder-blocks
 
 DEFINES += QT_NO_FOREACH
 
+tagFile=$$PWD/../../.tag
+tag=
+exists($$tagFile) {
+    tag=$$cat($$tagFile, singleline)
+    QMAKE_INTERNAL_INCLUDED_FILES += $$tagFile
+}
+!equals(tag, "$${LITERAL_DOLLAR}Format:%H$${LITERAL_DOLLAR}") {
+    DEFINES += QML_COMPILE_HASH="$$tag"
+} else:exists($$PWD/../../.git) {
+    commit=$$system(git describe --tags --always --long --dirty)
+    DEFINES += QML_COMPILE_HASH="$$commit"
+}
+
 exists("qqml_enable_gcov") {
     QMAKE_CXXFLAGS = -fprofile-arcs -ftest-coverage -fno-elide-constructors
     LIBS_PRIVATE += -lgcov
diff --git a/src/qml/qml/qqmlcontext.cpp b/src/qml/qml/qqmlcontext.cpp
index 531d9ae457..37cb328b36 100644
--- a/src/qml/qml/qqmlcontext.cpp
+++ b/src/qml/qml/qqmlcontext.cpp
@@ -161,6 +161,7 @@ QQmlContext::QQmlContext(QQmlEngine *e, bool)
 {
     Q_D(QQmlContext);
     d->data = new QQmlContextData(this);
+    ++d->data->refCount;
 
     d->data->engine = e;
 }
@@ -174,6 +175,7 @@ QQmlContext::QQmlContext(QQmlEngine *engine, QObject *parent)
 {
     Q_D(QQmlContext);
     d->data = new QQmlContextData(this);
+    ++d->data->refCount;
 
     d->data->setParent(engine?QQmlContextData::get(engine->rootContext()):0);
 }
@@ -187,6 +189,7 @@ QQmlContext::QQmlContext(QQmlContext *parentContext, QObject *parent)
 {
     Q_D(QQmlContext);
     d->data = new QQmlContextData(this);
+    ++d->data->refCount;
 
     d->data->setParent(parentContext?QQmlContextData::get(parentContext):0);
 }
@@ -199,6 +202,7 @@ QQmlContext::QQmlContext(QQmlContextData *data)
 {
     Q_D(QQmlContext);
     d->data = data;
+    // don't add a refcount here, as the data owns this context
 }
 
 /*!
@@ -212,7 +216,8 @@ QQmlContext::~QQmlContext()
 {
     Q_D(QQmlContext);
 
-    if (!d->data->isInternal)
+    d->data->publicContext = 0;
+    if (!--d->data->refCount)
         d->data->destroy();
 }
 
@@ -521,12 +526,12 @@ QQmlContextData::QQmlContextData()
 }
 
 QQmlContextData::QQmlContextData(QQmlContext *ctxt)
-: parent(0), engine(0), isInternal(false), ownedByParent(false), isJSContext(false),
-  isPragmaLibraryContext(false), unresolvedNames(false), hasEmittedDestruction(false), isRootObjectInCreation(false),
-  publicContext(ctxt), incubator(0), componentObjectIndex(-1),
-  contextObject(0), childContexts(0), nextChild(0), prevChild(0),
-  expressions(0), contextObjects(0), contextGuards(0), idValues(0), idValueCount(0), linkedContext(0),
-  componentAttached(0)
+    : engine(0), isInternal(false), isJSContext(false),
+      isPragmaLibraryContext(false), unresolvedNames(false), hasEmittedDestruction(false), isRootObjectInCreation(false),
+      publicContext(ctxt), incubator(0), componentObjectIndex(-1),
+      contextObject(0), nextChild(0), prevChild(0),
+      expressions(0), contextObjects(0), idValues(0), idValueCount(0),
+      componentAttached(0)
 {
 }
 
@@ -563,11 +568,8 @@ void QQmlContextData::invalidate()
     emitDestruction();
 
     while (childContexts) {
-        if (childContexts->ownedByParent) {
-            childContexts->destroy();
-        } else {
-            childContexts->invalidate();
-        }
+        Q_ASSERT(childContexts != this);
+        childContexts->invalidate();
     }
 
     if (prevChild) {
@@ -601,12 +603,17 @@ void QQmlContextData::clearContext()
 
 void QQmlContextData::destroy()
 {
-    if (linkedContext)
-        linkedContext->destroy();
+    Q_ASSERT(refCount == 0);
+    linkedContext = 0;
 
-    if (engine) invalidate();
+    // avoid recursion
+    ++refCount;
+    if (engine)
+        invalidate();
 
+    Q_ASSERT(refCount == 1);
     clearContext();
+    Q_ASSERT(refCount == 1);
 
     while (contextObjects) {
         QQmlData *co = contextObjects;
@@ -617,6 +624,7 @@ void QQmlContextData::destroy()
         co->nextContextObject = 0;
         co->prevContextObject = 0;
     }
+    Q_ASSERT(refCount == 1);
 
     QQmlGuardedContextData *contextGuard = contextGuards;
     while (contextGuard) {
@@ -627,17 +635,29 @@ void QQmlContextData::destroy()
         contextGuard = next;
     }
     contextGuards = 0;
+    Q_ASSERT(refCount == 1);
 
     delete [] idValues;
+    idValues = 0;
 
-    if (isInternal)
+    Q_ASSERT(refCount == 1);
+    if (publicContext) {
+        // the QQmlContext destructor will remove one ref again
+        ++refCount;
         delete publicContext;
+    }
+
+    Q_ASSERT(refCount == 1);
+    --refCount;
+    Q_ASSERT(refCount == 0);
 
     delete this;
 }
 
-void QQmlContextData::setParent(QQmlContextData *p, bool parentTakesOwnership)
+void QQmlContextData::setParent(QQmlContextData *p)
 {
+    if (p == parent)
+        return;
     if (p) {
         parent = p;
         engine = p->engine;
@@ -645,7 +665,6 @@ void QQmlContextData::setParent(QQmlContextData *p, bool parentTakesOwnership)
         if (nextChild) nextChild->prevChild = &nextChild;
         prevChild = &p->childContexts;
         p->childContexts = this;
-        ownedByParent = parentTakesOwnership;
     }
 }
 
@@ -660,6 +679,10 @@ void QQmlContextData::refreshExpressionsRecursive(QQmlJavaScriptExpression *expr
         expression->refresh();
 }
 
+QQmlContextData::~QQmlContextData()
+{
+}
+
 static inline bool expressions_to_run(QQmlContextData *ctxt, bool isGlobalRefresh)
 {
     return ctxt->expressions && (!isGlobalRefresh || ctxt->unresolvedNames);
@@ -795,7 +818,7 @@ QQmlContextPrivate *QQmlContextData::asQQmlContextPrivate()
 void QQmlContextData::initFromTypeCompilationUnit(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &unit, int subComponentIndex)
 {
     typeCompilationUnit = unit;
-    componentObjectIndex = subComponentIndex == -1 ? typeCompilationUnit->data->indexOfRootObject : subComponentIndex;
+    componentObjectIndex = subComponentIndex == -1 ? /*root object*/0 : subComponentIndex;
     Q_ASSERT(!idValues);
     idValueCount = typeCompilationUnit->data->objectAt(componentObjectIndex)->nNamedObjectsInComponent;
     idValues = new ContextGuard[idValueCount];
diff --git a/src/qml/qml/qqmlcontext_p.h b/src/qml/qml/qqmlcontext_p.h
index a259fd62d8..d01820a430 100644
--- a/src/qml/qml/qqmlcontext_p.h
+++ b/src/qml/qml/qqmlcontext_p.h
@@ -78,6 +78,7 @@ class QQmlExpression;
 class QQmlExpressionPrivate;
 class QQmlJavaScriptExpression;
 class QQmlContextData;
+class QQmlGuardedContextData;
 class QQmlIncubatorPrivate;
 
 class QQmlContextPrivate : public QObjectPrivate
@@ -106,7 +107,7 @@ public:
 };
 
 class QQmlComponentAttached;
-class QQmlGuardedContextData;
+
 class Q_QML_PRIVATE_EXPORT QQmlContextData
 {
 public:
@@ -114,7 +115,6 @@ public:
     QQmlContextData(QQmlContext *);
     void emitDestruction();
     void clearContext();
-    void destroy();
     void invalidate();
 
     inline bool isValid() const {
@@ -122,10 +122,10 @@ public:
     }
 
     // My parent context and engine
-    QQmlContextData *parent;
+    QQmlContextData *parent = nullptr;
     QQmlEngine *engine;
 
-    void setParent(QQmlContextData *, bool parentTakesOwnership = false);
+    void setParent(QQmlContextData *);
     void refreshExpressions();
 
     void addObject(QObject *);
@@ -136,14 +136,14 @@ public:
     // If internal is false publicContext owns this.
     QQmlContext *asQQmlContext();
     QQmlContextPrivate *asQQmlContextPrivate();
+    quint32 refCount = 0;
     quint32 isInternal:1;
-    quint32 ownedByParent:1; // unrelated to isInternal; parent context deletes children if true.
     quint32 isJSContext:1;
     quint32 isPragmaLibraryContext:1;
     quint32 unresolvedNames:1; // True if expressions in this context failed to resolve a toplevel name
     quint32 hasEmittedDestruction:1;
     quint32 isRootObjectInCreation:1;
-    quint32 dummy:25;
+    quint32 dummy:26;
     QQmlContext *publicContext;
 
     // The incubator that is constructing this context if any
@@ -178,7 +178,7 @@ public:
     QQmlRefPointer<QQmlTypeNameCache> imports;
 
     // My children
-    QQmlContextData *childContexts;
+    QQmlContextData *childContexts = 0;
 
     // My peers in parent's childContexts list
     QQmlContextData  *nextChild;
@@ -191,7 +191,7 @@ public:
     QQmlData *contextObjects;
 
     // Doubly-linked list of context guards (XXX merge with contextObjects)
-    QQmlGuardedContextData *contextGuards;
+    QQmlGuardedContextData *contextGuards = 0;
 
     // id guards
     struct ContextGuard : public QQmlGuard<QObject>
@@ -210,7 +210,7 @@ public:
     void setIdProperty(int, QObject *);
 
     // Linked contexts. this owns linkedContext.
-    QQmlContextData *linkedContext;
+    QQmlContextDataRef linkedContext;
 
     // Linked list of uses of the Component attached property in this
     // context
@@ -224,91 +224,137 @@ public:
     }
 
 private:
+    friend class QQmlContextDataRef;
+    friend class QQmlContext; // needs to do manual refcounting :/
     void refreshExpressionsRecursive(bool isGlobal);
     void refreshExpressionsRecursive(QQmlJavaScriptExpression *);
-    ~QQmlContextData() {}
+    ~QQmlContextData();
+    void destroy();
 };
 
+
 class QQmlGuardedContextData
 {
 public:
-    inline QQmlGuardedContextData();
-    inline QQmlGuardedContextData(QQmlContextData *);
-    inline ~QQmlGuardedContextData();
-
-    inline QQmlContextData *contextData() const;
+    inline QQmlGuardedContextData() = default;
+    inline QQmlGuardedContextData(QQmlContextData *data)
+    { setContextData(data); }
+    inline ~QQmlGuardedContextData()
+    { clear(); }
+
+    inline QQmlContextData *contextData() const
+    { return m_contextData; }
     inline void setContextData(QQmlContextData *);
 
     inline bool isNull() const { return !m_contextData; }
 
     inline operator QQmlContextData*() const { return m_contextData; }
     inline QQmlContextData* operator->() const { return m_contextData; }
-    inline QQmlGuardedContextData &operator=(QQmlContextData *d);
+    inline QQmlGuardedContextData &operator=(QQmlContextData *d) {
+        setContextData(d); return *this;
+    }
 
 private:
-    QQmlGuardedContextData &operator=(const QQmlGuardedContextData &);
-    QQmlGuardedContextData(const QQmlGuardedContextData &);
+    QQmlGuardedContextData &operator=(const QQmlGuardedContextData &) = delete;
+    QQmlGuardedContextData(const QQmlGuardedContextData &) = delete;
     friend class QQmlContextData;
 
     inline void clear();
 
-    QQmlContextData *m_contextData;
-    QQmlGuardedContextData  *m_next;
-    QQmlGuardedContextData **m_prev;
+    QQmlContextData *m_contextData = 0;
+    QQmlGuardedContextData  *m_next = 0;
+    QQmlGuardedContextData **m_prev = 0;
 };
 
-QQmlGuardedContextData::QQmlGuardedContextData()
-: m_contextData(0), m_next(0), m_prev(0)
+
+void QQmlGuardedContextData::setContextData(QQmlContextData *contextData)
+ {
+    if (m_contextData == contextData)
+        return;
+    clear();
+
+    if (contextData) {
+        m_contextData = contextData;
+        m_next = contextData->contextGuards;
+        if (m_next) m_next->m_prev = &m_next;
+        m_prev = &contextData->contextGuards;
+        contextData->contextGuards = this;
+    }
+}
+
+void QQmlGuardedContextData::clear()
+{
+    if (m_prev) {
+        *m_prev = m_next;
+        if (m_next) m_next->m_prev = m_prev;
+        m_contextData = 0;
+        m_next = 0;
+        m_prev = 0;
+    }
+}
+
+QQmlContextDataRef::QQmlContextDataRef()
+    : m_contextData(0)
 {
 }
 
-QQmlGuardedContextData::QQmlGuardedContextData(QQmlContextData *data)
-: m_contextData(0), m_next(0), m_prev(0)
+QQmlContextDataRef::QQmlContextDataRef(const QQmlContextDataRef &other)
+    : m_contextData(other.m_contextData)
 {
-    setContextData(data);
+    if (m_contextData)
+        ++m_contextData->refCount;
 }
 
-QQmlGuardedContextData::~QQmlGuardedContextData()
+QQmlContextDataRef::QQmlContextDataRef(QQmlContextData *data)
+    : m_contextData(data)
+{
+    if (m_contextData)
+        ++m_contextData->refCount;
+}
+
+QQmlContextDataRef::~QQmlContextDataRef()
 {
     clear();
 }
 
-void QQmlGuardedContextData::setContextData(QQmlContextData *contextData)
+void QQmlContextDataRef::setContextData(QQmlContextData *contextData)
 {
+    if (m_contextData == contextData)
+        return;
     clear();
 
     if (contextData) {
         m_contextData = contextData;
-        m_next = contextData->contextGuards;
-        if (m_next) m_next->m_prev = &m_next;
-        m_prev = &contextData->contextGuards;
-        contextData->contextGuards = this;
+        ++m_contextData->refCount;
     }
 }
 
-QQmlContextData *QQmlGuardedContextData::contextData() const
+QQmlContextData *QQmlContextDataRef::contextData() const
 {
     return m_contextData;
 }
 
-void QQmlGuardedContextData::clear()
+void QQmlContextDataRef::clear()
 {
-    if (m_prev) {
-        *m_prev = m_next;
-        if (m_next) m_next->m_prev = m_prev;
-        m_contextData = 0;
-        m_next = 0;
-        m_prev = 0;
-    }
+    if (m_contextData && !--m_contextData->refCount)
+        m_contextData->destroy();
+    m_contextData = 0;
 }
 
-QQmlGuardedContextData &
-QQmlGuardedContextData::operator=(QQmlContextData *d)
+QQmlContextDataRef &
+QQmlContextDataRef::operator=(QQmlContextData *d)
 {
     setContextData(d);
     return *this;
 }
 
+QQmlContextDataRef &
+QQmlContextDataRef::operator=(const QQmlContextDataRef &other)
+{
+    setContextData(other.m_contextData);
+    return *this;
+}
+
 QQmlContextData::ContextGuard::ContextGuard()
 : context(0)
 {
diff --git a/src/qml/qml/qqmldata_p.h b/src/qml/qml/qqmldata_p.h
index 2083326cd5..75ea720358 100644
--- a/src/qml/qml/qqmldata_p.h
+++ b/src/qml/qml/qqmldata_p.h
@@ -78,6 +78,34 @@ struct CompilationUnit;
 }
 }
 
+// This is declared here because QQmlData below needs it and this file
+// in turn is included from qqmlcontext_p.h.
+class QQmlContextData;
+class Q_QML_PRIVATE_EXPORT QQmlContextDataRef
+{
+public:
+    inline QQmlContextDataRef();
+    inline QQmlContextDataRef(QQmlContextData *);
+    inline QQmlContextDataRef(const QQmlContextDataRef &);
+    inline ~QQmlContextDataRef();
+
+    inline QQmlContextData *contextData() const;
+    inline void setContextData(QQmlContextData *);
+
+    inline bool isNull() const { return !m_contextData; }
+
+    inline operator QQmlContextData*() const { return m_contextData; }
+    inline QQmlContextData* operator->() const { return m_contextData; }
+    inline QQmlContextDataRef &operator=(QQmlContextData *d);
+    inline QQmlContextDataRef &operator=(const QQmlContextDataRef &other);
+
+private:
+
+    inline void clear();
+
+    QQmlContextData *m_contextData;
+};
+
 // This class is structured in such a way, that simply zero'ing it is the
 // default state for elemental object allocations.  This is crucial in the
 // workings of the QQmlInstruction::CreateSimpleObject instruction.
@@ -114,7 +142,6 @@ public:
 
     quint32 ownedByQml1:1; // This bit is shared with QML1's QDeclarativeData.
     quint32 ownMemory:1;
-    quint32 ownContext:1;
     quint32 indestructible:1;
     quint32 explicitIndestructibleSet:1;
     quint32 hasTaintedV4Object:1;
@@ -127,7 +154,7 @@ public:
     quint32 hasInterceptorMetaObject:1;
     quint32 hasVMEMetaObject:1;
     quint32 parentFrozen:1;
-    quint32 dummy:21;
+    quint32 dummy:22;
 
     // When bindingBitsSize < sizeof(ptr), we store the binding bit flags inside
     // bindingBitsValue. When we need more than sizeof(ptr) bits, we allocated
@@ -161,9 +188,10 @@ public:
     void disconnectNotifiers();
 
     // The context that created the C++ object
-    QQmlContextData *context;
+    QQmlContextData *context = 0;
     // The outermost context in which this object lives
-    QQmlContextData *outerContext;
+    QQmlContextData *outerContext = 0;
+    QQmlContextDataRef ownContext;
 
     QQmlAbstractBinding *bindings;
     QQmlBoundSignal *signalHandlers;
diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index 194c58b805..5f4e291775 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -718,8 +718,13 @@ QQmlEnginePrivate::~QQmlEnginePrivate()
 void QQmlPrivate::qdeclarativeelement_destructor(QObject *o)
 {
     if (QQmlData *d = QQmlData::get(o)) {
-        if (d->ownContext && d->context) {
-            d->context->destroy();
+        if (d->ownContext) {
+            for (QQmlContextData *lc = d->ownContext->linkedContext; lc; lc = lc->linkedContext)
+                lc->invalidate();
+            d->ownContext->invalidate();
+            if (d->ownContext->contextObject == o)
+                d->ownContext->contextObject = nullptr;
+            d->ownContext = 0;
             d->context = 0;
         }
 
@@ -735,10 +740,10 @@ void QQmlPrivate::qdeclarativeelement_destructor(QObject *o)
 }
 
 QQmlData::QQmlData()
-    : ownedByQml1(false), ownMemory(true), ownContext(false), indestructible(true), explicitIndestructibleSet(false),
+    : ownedByQml1(false), ownMemory(true), indestructible(true), explicitIndestructibleSet(false),
       hasTaintedV4Object(false), isQueuedForDeletion(false), rootObjectInCreation(false),
       hasInterceptorMetaObject(false), hasVMEMetaObject(false), parentFrozen(false),
-      bindingBitsSize(MaxInlineBits), bindingBitsValue(0), notifyList(0), context(0), outerContext(0),
+      bindingBitsSize(MaxInlineBits), bindingBitsValue(0), notifyList(0),
       bindings(0), signalHandlers(0), nextContextObject(0), prevContextObject(0),
       lineNumber(0), columnNumber(0), jsEngineId(0), compilationUnit(0), deferredData(0),
       propertyCache(0), guards(0), extendedData(0)
@@ -888,8 +893,12 @@ void QQmlData::setQueuedForDeletion(QObject *object)
 {
     if (object) {
         if (QQmlData *ddata = QQmlData::get(object)) {
-            if (ddata->ownContext && ddata->context)
+            if (ddata->ownContext) {
+                Q_ASSERT(ddata->ownContext == ddata->context);
                 ddata->context->emitDestruction();
+                ddata->ownContext = 0;
+                ddata->context = 0;
+            }
             ddata->isQueuedForDeletion = true;
         }
     }
@@ -1786,8 +1795,7 @@ void QQmlData::destroyed(QObject *object)
     if (propertyCache)
         propertyCache->release();
 
-    if (ownContext && context)
-        context->destroy();
+    ownContext = 0;
 
     while (guards) {
         QQmlGuard<QObject> *guard = static_cast<QQmlGuard<QObject> *>(guards);
diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index 66c0be41da..bc8be04f24 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -472,6 +472,17 @@ void findCompositeSingletons(const QQmlImportNamespace &set, QList<QQmlImports::
                 resultList.append(ref);
             }
         }
+
+        if (QQmlTypeModule *module = QQmlMetaType::typeModule(import->uri, import->majversion)) {
+            module->walkCompositeSingletons([&resultList, &set](const QQmlType &singleton) {
+                QQmlImports::CompositeSingletonReference ref;
+                ref.typeName = singleton.elementName();
+                ref.prefix = set.prefix;
+                ref.majorVersion = singleton.majorVersion();
+                ref.minorVersion = singleton.minorVersion();
+                resultList.append(ref);
+            });
+        }
     }
 }
 
diff --git a/src/qml/qml/qqmlmetatype.cpp b/src/qml/qml/qqmlmetatype.cpp
index bddbda5832..8e6be538ef 100644
--- a/src/qml/qml/qqmlmetatype.cpp
+++ b/src/qml/qml/qqmlmetatype.cpp
@@ -1306,6 +1306,13 @@ void QQmlType::derefHandle(QQmlTypePrivate *priv)
         delete priv;
 }
 
+int QQmlType::refCount(QQmlTypePrivate *priv)
+{
+    if (priv)
+        return priv->refCount;
+    return -1;
+}
+
 namespace {
 template <typename QQmlTypeContainer>
 void removeQQmlTypePrivate(QQmlTypeContainer &container, const QQmlTypePrivate *reference)
@@ -1377,7 +1384,7 @@ void QQmlTypeModulePrivate::add(QQmlTypePrivate *type)
 void QQmlTypeModulePrivate::remove(const QQmlTypePrivate *type)
 {
     for (TypeHash::ConstIterator elementIt = typeHash.begin(); elementIt != typeHash.end();) {
-        QList<QQmlTypePrivate *> &list = typeHash[elementIt.key()];
+        QList<QQmlTypePrivate *> &list = const_cast<QList<QQmlTypePrivate *> &>(elementIt.value());
 
         removeQQmlTypePrivate(list, type);
 
@@ -1420,6 +1427,18 @@ QQmlType QQmlTypeModule::type(const QV4::String *name, int minor) const
     return QQmlType();
 }
 
+void QQmlTypeModule::walkCompositeSingletons(const std::function<void(const QQmlType &)> &callback) const
+{
+    QMutexLocker lock(metaTypeDataLock());
+    for (auto typeCandidates = d->typeHash.begin(), end = d->typeHash.end();
+         typeCandidates != end; ++typeCandidates) {
+        for (auto type: typeCandidates.value()) {
+            if (type->regType == QQmlType::CompositeSingletonType)
+                callback(QQmlType(type));
+        }
+    }
+}
+
 QQmlTypeModuleVersion::QQmlTypeModuleVersion()
 : m_module(0), m_minor(0)
 {
@@ -1484,6 +1503,7 @@ void qmlClearTypeRegistrations() // Declared in qqml.h
     data->urlToNonFileImportType.clear();
     data->metaObjectToType.clear();
     data->uriToModule.clear();
+    data->undeletableTypes.clear();
 
     QQmlEnginePrivate::baseModulesUninitialized = true; //So the engine re-registers its types
 #if QT_CONFIG(library)
diff --git a/src/qml/qml/qqmlmetatype_p.h b/src/qml/qml/qqmlmetatype_p.h
index 8eb91f321a..720c6d904a 100644
--- a/src/qml/qml/qqmlmetatype_p.h
+++ b/src/qml/qml/qqmlmetatype_p.h
@@ -253,6 +253,7 @@ public:
     QQmlTypePrivate *priv() const { return d; }
     static void refHandle(QQmlTypePrivate *priv);
     static void derefHandle(QQmlTypePrivate *priv);
+    static int refCount(QQmlTypePrivate *priv);
 
     enum RegistrationType {
         CppType = 0,
@@ -307,6 +308,8 @@ public:
     QQmlType type(const QHashedStringRef &, int) const;
     QQmlType type(const QV4::String *, int) const;
 
+    void walkCompositeSingletons(const std::function<void(const QQmlType &)> &callback) const;
+
     QQmlTypeModulePrivate *priv() { return d; }
 private:
     //Used by register functions and creates the QQmlTypeModule for them
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index 11d090a415..1c15022124 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -163,7 +163,7 @@ QObject *QQmlObjectCreator::create(int subComponentIndex, QObject *parent, QQmlI
     int objectToCreate;
 
     if (subComponentIndex == -1) {
-        objectToCreate = qmlUnit->indexOfRootObject;
+        objectToCreate = /*root object*/0;
     } else {
         const QV4::CompiledData::Object *compObj = qmlUnit->objectAt(subComponentIndex);
         objectToCreate = compObj->bindingTable()->value.objectIndex;
@@ -1122,7 +1122,7 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
     }
 
     ddata->setImplicitDestructible();
-    if (static_cast<quint32>(index) == qmlUnit->indexOfRootObject || ddata->rootObjectInCreation) {
+    if (static_cast<quint32>(index) == /*root object*/0 || ddata->rootObjectInCreation) {
         if (ddata->context) {
             Q_ASSERT(ddata->context != context);
             Q_ASSERT(ddata->outerContext);
@@ -1132,7 +1132,7 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
             c->linkedContext = context;
         } else
             context->addObject(instance);
-        ddata->ownContext = true;
+        ddata->ownContext = ddata->context;
     } else if (!ddata->context)
         context->addObject(instance);
 
diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index 7e298a1f2d..d5ed5792b3 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -700,8 +700,7 @@ void QQmlDataBlob::notifyComplete(QQmlDataBlob *blob)
 {
     Q_ASSERT(m_waitingFor.contains(blob));
     Q_ASSERT(blob->status() == Error || blob->status() == Complete);
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(typeLoader()->engine())->profiler,
-                               blob);
+    QQmlCompilingProfiler prof(typeLoader()->profiler(), blob);
 
     m_inCallback = true;
 
@@ -963,6 +962,14 @@ void QQmlTypeLoader::invalidate()
 #endif // qml_network
 }
 
+#ifndef QT_NO_QML_DEBUGGER
+void QQmlTypeLoader::setProfiler(QQmlProfiler *profiler)
+{
+    Q_ASSERT(!m_profiler);
+    m_profiler.reset(profiler);
+}
+#endif
+
 void QQmlTypeLoader::lock()
 {
     m_thread->lock();
@@ -1262,7 +1269,7 @@ void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QString &fileName)
 void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QQmlDataBlob::SourceCodeData &d)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(engine())->profiler, blob);
+    QQmlCompilingProfiler prof(profiler(), blob);
 
     blob->m_inCallback = true;
 
@@ -1282,7 +1289,7 @@ void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QQmlDataBlob::SourceCodeD
 void QQmlTypeLoader::setCachedUnit(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(engine())->profiler, blob);
+    QQmlCompilingProfiler prof(profiler(), blob);
 
     blob->m_inCallback = true;
 
@@ -2814,7 +2821,7 @@ QV4::ReturnedValue QQmlScriptData::scriptValueForContext(QQmlContextData *parent
         effectiveCtxt = 0;
 
     // Create the script context if required
-    QQmlContextData *ctxt = new QQmlContextData;
+    QQmlContextDataRef ctxt(new QQmlContextData);
     ctxt->isInternal = true;
     ctxt->isJSContext = true;
     if (shared)
@@ -2834,7 +2841,7 @@ QV4::ReturnedValue QQmlScriptData::scriptValueForContext(QQmlContextData *parent
     }
 
     if (effectiveCtxt) {
-        ctxt->setParent(effectiveCtxt, true);
+        ctxt->setParent(effectiveCtxt);
     } else {
         ctxt->engine = parentCtxt->engine; // Fix for QTBUG-21620
     }
@@ -2856,12 +2863,10 @@ QV4::ReturnedValue QQmlScriptData::scriptValueForContext(QQmlContextData *parent
     if (!m_program) {
         if (shared)
             m_loaded = true;
-        ctxt->destroy();
         return QV4::Encode::undefined();
     }
 
     QV4::Scoped<QV4::QmlContext> qmlContext(scope, QV4::QmlContext::create(v4->rootContext(), ctxt, 0));
-    qmlContext->takeContextOwnership();
 
     m_program->qmlContext.set(scope.engine, qmlContext);
     m_program->run();
diff --git a/src/qml/qml/qqmltypeloader_p.h b/src/qml/qml/qqmltypeloader_p.h
index 05923f77e8..c214f0cd43 100644
--- a/src/qml/qml/qqmltypeloader_p.h
+++ b/src/qml/qml/qqmltypeloader_p.h
@@ -84,6 +84,7 @@ class QQmlComponentPrivate;
 class QQmlTypeData;
 class QQmlTypeLoader;
 class QQmlExtensionInterface;
+class QQmlProfiler;
 struct QQmlCompileError;
 
 namespace QmlIR {
@@ -248,7 +249,7 @@ private:
     QString m_location;
 };
 
-class Q_AUTOTEST_EXPORT QQmlTypeLoader
+class Q_QML_PRIVATE_EXPORT QQmlTypeLoader
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlTypeLoader)
 public:
@@ -320,6 +321,15 @@ public:
     void initializeEngine(QQmlExtensionInterface *, const char *);
     void invalidate();
 
+#ifdef QT_NO_QML_DEBUGGER
+    QQmlProfiler *profiler() const { return nullptr; }
+    void setProfiler(QQmlProfiler *) {}
+#else
+    QQmlProfiler *profiler() const { return m_profiler.data(); }
+    void setProfiler(QQmlProfiler *profiler);
+#endif // QT_NO_QML_DEBUGGER
+
+
 private:
     friend class QQmlDataBlob;
     friend class QQmlTypeLoaderThread;
@@ -368,6 +378,11 @@ private:
 
     QQmlEngine *m_engine;
     QQmlTypeLoaderThread *m_thread;
+
+#ifndef QT_NO_QML_DEBUGGER
+    QScopedPointer<QQmlProfiler> m_profiler;
+#endif
+
 #if QT_CONFIG(qml_network)
     NetworkReplies m_networkReplies;
 #endif
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index 113ef0c412..08f3d35e46 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -1058,7 +1058,7 @@ private:
     void readEncoding();
 
     PersistentValue m_thisObject;
-    QQmlGuardedContextData m_qmlContext;
+    QQmlContextDataRef m_qmlContext;
 
     static void dispatchCallback(Object *thisObj, QQmlContextData *context);
     void dispatchCallback();
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
index 64ab436363..1630efe081 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
@@ -1152,6 +1152,10 @@ void QtObject::method_createQmlObject(const BuiltinFunction *, Scope &scope, Cal
     if (!component.isReady())
         THROW_GENERIC_ERROR("Qt.createQmlObject(): Component is not ready");
 
+    if (!effectiveContext->isValid()) {
+        THROW_GENERIC_ERROR("Qt.createQmlObject(): Cannot create a component in an invalid context");
+    }
+
     QObject *obj = component.beginCreate(effectiveContext);
     if (obj) {
         QQmlData::get(obj, true)->explicitIndestructibleSet = false;
diff --git a/src/qml/types/qqmldelegatemodel.cpp b/src/qml/types/qqmldelegatemodel.cpp
index d54bdeede6..4d2a9746c3 100644
--- a/src/qml/types/qqmldelegatemodel.cpp
+++ b/src/qml/types/qqmldelegatemodel.cpp
@@ -269,7 +269,8 @@ QQmlDelegateModel::~QQmlDelegateModel()
             delete cacheItem->object;
 
             cacheItem->object = 0;
-            cacheItem->contextData->destroy();
+            cacheItem->contextData->invalidate();
+            Q_ASSERT(cacheItem->contextData->refCount == 1);
             cacheItem->contextData = 0;
             cacheItem->scriptRef -= 1;
         }
@@ -840,7 +841,8 @@ void QQDMIncubationTask::statusChanged(Status status)
         delete incubating->object;
         incubating->object = 0;
         if (incubating->contextData) {
-            incubating->contextData->destroy();
+            incubating->contextData->invalidate();
+            Q_ASSERT(incubating->contextData->refCount == 1);
             incubating->contextData = 0;
         }
         incubating->scriptRef = 0;
@@ -900,8 +902,10 @@ void QQmlDelegateModelPrivate::incubatorStatusChanged(QQDMIncubationTask *incuba
         delete cacheItem->object;
         cacheItem->object = 0;
         cacheItem->scriptRef -= 1;
-        if (cacheItem->contextData)
-            cacheItem->contextData->destroy();
+        if (cacheItem->contextData) {
+            cacheItem->contextData->invalidate();
+            Q_ASSERT(cacheItem->contextData->refCount == 1);
+        }
         cacheItem->contextData = 0;
 
         if (!cacheItem->isReferenced()) {
@@ -983,7 +987,7 @@ QObject *QQmlDelegateModelPrivate::object(Compositor::Group group, int index, bo
             if (QQmlAdaptorModelProxyInterface *proxy
                     = qobject_cast<QQmlAdaptorModelProxyInterface *>(cacheItem)) {
                 ctxt = new QQmlContextData;
-                ctxt->setParent(cacheItem->contextData, true);
+                ctxt->setParent(cacheItem->contextData);
                 ctxt->contextObject = proxy->proxiedObject();
             }
         }
@@ -1264,6 +1268,13 @@ void QQmlDelegateModel::_q_itemsInserted(int index, int count)
     d->emitChanges();
 }
 
+//### This method should be split in two. It will remove delegates, and it will re-render the list.
+// When e.g. QQmlListModel::remove is called, the removal of the delegates should be done on
+// QAbstractItemModel::rowsAboutToBeRemoved, and the re-rendering on
+// QAbstractItemModel::rowsRemoved. Currently both are done on the latter signal. The problem is
+// that the destruction of an item will emit a changed signal that ends up at the delegate, which
+// in turn will try to load the data from the model (which should have already freed it), resulting
+// in a use-after-free. See QTBUG-59256.
 void QQmlDelegateModelPrivate::itemsRemoved(
         const QVector<Compositor::Remove> &removes,
         QVarLengthArray<QVector<QQmlChangeSet::Change>, Compositor::MaximumGroupCount> *translatedRemoves,
@@ -1944,8 +1955,11 @@ void QQmlDelegateModelItem::destroyObject()
 
     QQmlData *data = QQmlData::get(object);
     Q_ASSERT(data);
-    if (data->ownContext && data->context)
-        data->context->clearContext();
+    if (data->ownContext) {
+        data->ownContext->clearContext();
+        data->ownContext = 0;
+        data->context = 0;
+    }
     object->deleteLater();
 
     if (attached) {
@@ -1953,7 +1967,7 @@ void QQmlDelegateModelItem::destroyObject()
         attached = 0;
     }
 
-    contextData->destroy();
+    contextData->invalidate();
     contextData = 0;
     object = 0;
 }
diff --git a/src/qml/types/qqmldelegatemodel_p_p.h b/src/qml/types/qqmldelegatemodel_p_p.h
index 4ebfd9b938..3759fe8667 100644
--- a/src/qml/types/qqmldelegatemodel_p_p.h
+++ b/src/qml/types/qqmldelegatemodel_p_p.h
@@ -135,7 +135,7 @@ public:
 
     QV4::ExecutionEngine *v4;
     QQmlDelegateModelItemMetaType * const metaType;
-    QQmlContextData *contextData;
+    QQmlContextDataRef contextData;
     QPointer<QObject> object;
     QPointer<QQmlDelegateModelAttached> attached;
     QQDMIncubationTask *incubationTask;
diff --git a/src/qml/types/qqmllistmodel.cpp b/src/qml/types/qqmllistmodel.cpp
index 20000557ee..d088a5da42 100644
--- a/src/qml/types/qqmllistmodel.cpp
+++ b/src/qml/types/qqmllistmodel.cpp
@@ -572,14 +572,20 @@ void ListModel::clear()
     elements.clear();
 }
 
-void ListModel::remove(int index, int count)
+QVector<std::function<void()>> ListModel::remove(int index, int count)
 {
+    QVector<std::function<void()>> toDestroy;
+    auto layout = m_layout;
     for (int i=0 ; i < count ; ++i) {
-        elements[index+i]->destroy(m_layout);
-        delete elements[index+i];
+        auto element = elements[index+i];
+        toDestroy.append([element, layout](){
+            element->destroy(layout);
+            delete element;
+        });
     }
     elements.remove(index, count);
     updateCacheIndices(index);
+    return toDestroy;
 }
 
 void ListModel::insert(int elementIndex, QV4::Object *object)
@@ -1394,7 +1400,10 @@ void ModelObject::advanceIterator(Managed *m, ObjectIterator *it, Value *name, u
         p->value = v4->fromVariant(value);
         return;
     }
-    QV4::QObjectWrapper::advanceIterator(m, it, name, index, p, attributes);
+    // Fall back to QV4::Object as opposed to QV4::QObjectWrapper otherwise it will add
+    // unnecessary entries that relate to the roles used. These just create extra work
+    // later on as they will just be ignored.
+    QV4::Object::advanceIterator(m, it, name, index, p, attributes);
 }
 
 DEFINE_OBJECT_VTABLE(ModelObject);
@@ -2059,15 +2068,22 @@ void QQmlListModel::remove(QQmlV4Function *args)
 
         emitItemsAboutToBeRemoved(index, removeCount);
 
+        QVector<std::function<void()>> toDestroy;
         if (m_dynamicRoles) {
-            for (int i=0 ; i < removeCount ; ++i)
-                delete m_modelObjects[index+i];
+            for (int i=0 ; i < removeCount ; ++i) {
+                auto modelObject = m_modelObjects[index+i];
+                toDestroy.append([modelObject](){
+                    delete modelObject;
+                });
+            }
             m_modelObjects.remove(index, removeCount);
         } else {
-            m_listModel->remove(index, removeCount);
+            toDestroy = m_listModel->remove(index, removeCount);
         }
 
         emitItemsRemoved(index, removeCount);
+        for (const auto &destroyer : toDestroy)
+            destroyer();
     } else {
         qmlWarning(this) << tr("remove: incorrect number of arguments");
     }
diff --git a/src/qml/types/qqmllistmodel_p_p.h b/src/qml/types/qqmllistmodel_p_p.h
index e2653c220d..77d2002afa 100644
--- a/src/qml/types/qqmllistmodel_p_p.h
+++ b/src/qml/types/qqmllistmodel_p_p.h
@@ -367,7 +367,7 @@ public:
     void insert(int elementIndex, QV4::Object *object);
 
     void clear();
-    void remove(int index, int count);
+    Q_REQUIRED_RESULT QVector<std::function<void()>> remove(int index, int count);
 
     int appendElement();
     void insertElement(int index);
diff --git a/src/qmltest/quicktest.cpp b/src/qmltest/quicktest.cpp
index a9bf02aeca..3cd1694dd0 100644
--- a/src/qmltest/quicktest.cpp
+++ b/src/qmltest/quicktest.cpp
@@ -271,7 +271,7 @@ private:
         TestCaseEnumerationResult result;
 
         if (!object) // Start at root of compilation unit if not enumerating a specific child
-            object = compilationUnit->objectAt(compilationUnit->rootObjectIndex());
+            object = compilationUnit->objectAt(0);
 
         if (CompilationUnit *superTypeUnit = compilationUnit->resolvedTypes.value(object->inheritedTypeNameIndex)->compilationUnit) {
             // We have a non-C++ super type, which could indicate we're a subtype of a TestCase
diff --git a/src/quick/items/context2d/qquickcontext2dtexture.cpp b/src/quick/items/context2d/qquickcontext2dtexture.cpp
index df6dd9dba2..a8bf14ba9f 100644
--- a/src/quick/items/context2d/qquickcontext2dtexture.cpp
+++ b/src/quick/items/context2d/qquickcontext2dtexture.cpp
@@ -54,6 +54,9 @@
 #include <QtGui/QGuiApplication>
 
 QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(lcCanvas, "qt.quick.canvas")
+
 #if QT_CONFIG(opengl)
 #define QT_MINIMUM_FBO_SIZE 64
 
@@ -96,6 +99,7 @@ QQuickContext2DTexture::QQuickContext2DTexture()
 #endif
     , m_surface(0)
     , m_item(0)
+    , m_canvasDevicePixelRatio(1)
     , m_canvasWindowChanged(false)
     , m_dirtyTexture(false)
     , m_smooth(true)
@@ -161,12 +165,22 @@ void QQuickContext2DTexture::setItem(QQuickCanvasItem* item)
 
 bool QQuickContext2DTexture::setCanvasWindow(const QRect& r)
 {
+    qreal canvasDevicePixelRatio = (m_item && m_item->window()) ?
+        m_item->window()->effectiveDevicePixelRatio() : qApp->devicePixelRatio();
+    if (!qFuzzyCompare(m_canvasDevicePixelRatio, canvasDevicePixelRatio)) {
+        qCDebug(lcCanvas, "%s device pixel ratio %.1lf -> %.1lf",
+                (m_item->objectName().isEmpty() ? "Canvas" : qPrintable(m_item->objectName())),
+                m_canvasDevicePixelRatio, canvasDevicePixelRatio);
+        m_canvasDevicePixelRatio = canvasDevicePixelRatio;
+        m_canvasWindowChanged = true;
+    }
+
     if (m_canvasWindow != r) {
         m_canvasWindow = r;
         m_canvasWindowChanged = true;
-        return true;
     }
-    return false;
+
+    return m_canvasWindowChanged;
 }
 
 bool QQuickContext2DTexture::setDirtyRect(const QRect &r)
@@ -549,9 +563,6 @@ QPaintDevice* QQuickContext2DFBOTexture::beginPainting()
 {
     QQuickContext2DTexture::beginPainting();
 
-    const qreal devicePixelRatio = (m_item && m_item->window()) ?
-        m_item->window()->effectiveDevicePixelRatio() : qApp->devicePixelRatio();
-
     if (m_canvasWindow.size().isEmpty()) {
         delete m_fbo;
         delete m_multisampledFbo;
@@ -566,7 +577,7 @@ QPaintDevice* QQuickContext2DFBOTexture::beginPainting()
         delete m_paint_device;
         m_paint_device = 0;
 
-        m_fboSize = npotAdjustedSize(m_canvasWindow.size() * devicePixelRatio);
+        m_fboSize = npotAdjustedSize(m_canvasWindow.size() * m_canvasDevicePixelRatio);
         m_canvasWindowChanged = false;
 
         if (doMultisampling()) {
@@ -604,7 +615,10 @@ QPaintDevice* QQuickContext2DFBOTexture::beginPainting()
         QOpenGLPaintDevice *gl_device = new QOpenGLPaintDevice(m_fbo->size());
         gl_device->setPaintFlipped(true);
         gl_device->setSize(m_fbo->size());
-        gl_device->setDevicePixelRatio(devicePixelRatio);
+        gl_device->setDevicePixelRatio(m_canvasDevicePixelRatio);
+        qCDebug(lcCanvas, "%s size %.1lf x %.1lf painting with size %d x %d DPR %.1lf",
+                (m_item->objectName().isEmpty() ? "Canvas" : qPrintable(m_item->objectName())),
+                m_item->width(), m_item->height(), m_fbo->size().width(), m_fbo->size().height(), m_canvasDevicePixelRatio);
         m_paint_device = gl_device;
     }
 
@@ -710,14 +724,15 @@ QPaintDevice* QQuickContext2DImageTexture::beginPainting()
     if (m_canvasWindow.size().isEmpty())
         return 0;
 
-    const qreal devicePixelRatio = (m_item && m_item->window()) ?
-        m_item->window()->effectiveDevicePixelRatio() : qApp->devicePixelRatio();
 
     if (m_canvasWindowChanged) {
-        m_image = QImage(m_canvasWindow.size() * devicePixelRatio, QImage::Format_ARGB32_Premultiplied);
-        m_image.setDevicePixelRatio(devicePixelRatio);
+        m_image = QImage(m_canvasWindow.size() * m_canvasDevicePixelRatio, QImage::Format_ARGB32_Premultiplied);
+        m_image.setDevicePixelRatio(m_canvasDevicePixelRatio);
         m_image.fill(0x00000000);
         m_canvasWindowChanged = false;
+        qCDebug(lcCanvas, "%s size %.1lf x %.1lf painting with size %d x %d DPR %.1lf",
+                (m_item->objectName().isEmpty() ? "Canvas" : qPrintable(m_item->objectName())),
+                m_item->width(), m_item->height(), m_image.size().width(), m_image.size().height(), m_canvasDevicePixelRatio);
     }
 
     return &m_image;
diff --git a/src/quick/items/context2d/qquickcontext2dtexture_p.h b/src/quick/items/context2d/qquickcontext2dtexture_p.h
index 97135816a2..81896dcdc1 100644
--- a/src/quick/items/context2d/qquickcontext2dtexture_p.h
+++ b/src/quick/items/context2d/qquickcontext2dtexture_p.h
@@ -168,6 +168,7 @@ protected:
     QSize m_canvasSize;
     QSize m_tileSize;
     QRect m_canvasWindow;
+    qreal m_canvasDevicePixelRatio;
 
     QMutex m_mutex;
     QWaitCondition m_condition;
diff --git a/src/quick/items/qquickanimatedimage.cpp b/src/quick/items/qquickanimatedimage.cpp
index a30d71dd1e..5bc5b0faff 100644
--- a/src/quick/items/qquickanimatedimage.cpp
+++ b/src/quick/items/qquickanimatedimage.cpp
@@ -279,8 +279,7 @@ void QQuickAnimatedImage::setSource(const QUrl &url)
 
     d->oldPlaying = isPlaying();
     if (d->_movie) {
-        delete d->_movie;
-        d->_movie = 0;
+        d->setMovie(nullptr);
     }
 
     d->url = url;
@@ -320,7 +319,7 @@ void QQuickAnimatedImage::load()
         QString lf = QQmlFile::urlToLocalFileOrQrc(loadUrl);
 
         if (!lf.isEmpty()) {
-            d->_movie = new QMovie(lf);
+            d->setMovie(new QMovie(lf));
             movieRequestFinished();
         } else {
 #if QT_CONFIG(qml_network)
@@ -366,14 +365,13 @@ void QQuickAnimatedImage::movieRequestFinished()
         }
 
         d->redirectCount=0;
-        d->_movie = new QMovie(d->reply);
+        d->setMovie(new QMovie(d->reply));
     }
 #endif
 
     if (!d->_movie || !d->_movie->isValid()) {
         qmlWarning(this) << "Error Reading Animated Image File " << d->url.toString();
-        delete d->_movie;
-        d->_movie = 0;
+        d->setMovie(nullptr);
         d->setImage(QImage());
         if (d->progress != 0) {
             d->progress = 0;
@@ -490,6 +488,18 @@ void QQuickAnimatedImage::componentComplete()
     load();
 }
 
+void QQuickAnimatedImagePrivate::setMovie(QMovie *movie)
+{
+    Q_Q(QQuickAnimatedImage);
+    const int oldFrameCount = q->frameCount();
+
+    delete _movie;
+    _movie = movie;
+
+    if (oldFrameCount != q->frameCount())
+        emit q->frameCountChanged();
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qquickanimatedimage_p.cpp"
diff --git a/src/quick/items/qquickanimatedimage_p.h b/src/quick/items/qquickanimatedimage_p.h
index 54da093259..94e44f27cd 100644
--- a/src/quick/items/qquickanimatedimage_p.h
+++ b/src/quick/items/qquickanimatedimage_p.h
@@ -69,7 +69,7 @@ class Q_AUTOTEST_EXPORT QQuickAnimatedImage : public QQuickImage
     Q_PROPERTY(bool playing READ isPlaying WRITE setPlaying NOTIFY playingChanged)
     Q_PROPERTY(bool paused READ isPaused WRITE setPaused NOTIFY pausedChanged)
     Q_PROPERTY(int currentFrame READ currentFrame WRITE setCurrentFrame NOTIFY frameChanged)
-    Q_PROPERTY(int frameCount READ frameCount)
+    Q_PROPERTY(int frameCount READ frameCount NOTIFY frameCountChanged)
 
     // read-only for AnimatedImage
     Q_PROPERTY(QSize sourceSize READ sourceSize NOTIFY sourceSizeChanged)
@@ -97,6 +97,7 @@ Q_SIGNALS:
     void playingChanged();
     void pausedChanged();
     void frameChanged();
+    void frameCountChanged();
 
 private Q_SLOTS:
     void movieUpdate();
diff --git a/src/quick/items/qquickanimatedimage_p_p.h b/src/quick/items/qquickanimatedimage_p_p.h
index 9eff6a44e3..68c4f2d359 100644
--- a/src/quick/items/qquickanimatedimage_p_p.h
+++ b/src/quick/items/qquickanimatedimage_p_p.h
@@ -91,6 +91,7 @@ public:
 #endif
     QMap<int, QQuickPixmap *> frameMap;
     QSize currentSourceSize;
+    void setMovie(QMovie *movie);
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickdrag.cpp b/src/quick/items/qquickdrag.cpp
index 41847e5f01..7c936ff21c 100644
--- a/src/quick/items/qquickdrag.cpp
+++ b/src/quick/items/qquickdrag.cpp
@@ -772,6 +772,7 @@ Qt::DropAction QQuickDragAttachedPrivate::startDrag(Qt::DropActions supportedAct
         drag->setPixmap(QPixmap::fromImage(pixmapLoader.image()));
     }
 
+    drag->setHotSpot(hotSpot.toPoint());
     emit q->dragStarted();
 
     Qt::DropAction dropAction = drag->exec(supportedActions);
diff --git a/src/quick/items/qquickflickable.cpp b/src/quick/items/qquickflickable.cpp
index ce584cd283..ee5f177855 100644
--- a/src/quick/items/qquickflickable.cpp
+++ b/src/quick/items/qquickflickable.cpp
@@ -56,6 +56,7 @@
 #include <QtCore/qmath.h>
 #include "qplatformdefs.h"
 
+#include <math.h>
 #include <cmath>
 
 QT_BEGIN_NAMESPACE
@@ -1771,6 +1772,7 @@ void QQuickFlickable::flick(qreal xVelocity, qreal yVelocity)
     d->vData.reset();
     d->hData.velocity = xVelocity;
     d->vData.velocity = yVelocity;
+    d->hData.vTime = d->vData.vTime = d->timeline.time();
 
     bool flickedX = d->flickX(xVelocity);
     bool flickedY = d->flickY(yVelocity);
diff --git a/src/quick/items/qquicktextedit.cpp b/src/quick/items/qquicktextedit.cpp
index da11913bde..8f3a8998f5 100644
--- a/src/quick/items/qquicktextedit.cpp
+++ b/src/quick/items/qquicktextedit.cpp
@@ -2511,7 +2511,7 @@ void QQuickTextEdit::updateSize()
 
     if (d->isImplicitResizeEnabled()) {
         // ### Setting the implicitWidth triggers another updateSize(), and unless there are bindings nothing has changed.
-        if (!widthValid() && !d->requireImplicitWidth)
+        if (!widthValid())
             setImplicitSize(newWidth + leftPadding() + rightPadding(), newHeight + topPadding() + bottomPadding());
         else
             setImplicitHeight(newHeight + topPadding() + bottomPadding());
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarelayer.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarelayer.cpp
index 2954f591ad..bd5d8f72c0 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarelayer.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarelayer.cpp
@@ -50,7 +50,7 @@ QSGSoftwareLayer::QSGSoftwareLayer(QSGRenderContext *renderContext)
     , m_renderer(0)
     , m_device_pixel_ratio(1)
     , m_mirrorHorizontal(false)
-    , m_mirrorVertical(false)
+    , m_mirrorVertical(true)
     , m_live(true)
     , m_grab(true)
     , m_recursive(false)
diff --git a/src/quick/scenegraph/coreapi/qsgrenderer.cpp b/src/quick/scenegraph/coreapi/qsgrenderer.cpp
index 8fbd402a2f..3ae79a933f 100644
--- a/src/quick/scenegraph/coreapi/qsgrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgrenderer.cpp
@@ -50,7 +50,9 @@
 
 QT_BEGIN_NAMESPACE
 
+#if QT_CONFIG(opengl)
 static const bool qsg_sanity_check = qEnvironmentVariableIntValue("QSG_SANITY_CHECK");
+#endif
 
 static QElapsedTimer frameTimer;
 static qint64 preprocessTime;
diff --git a/tests/auto/qml/qjsengine/tst_qjsengine.cpp b/tests/auto/qml/qjsengine/tst_qjsengine.cpp
index a3a2efd565..446f9b04a7 100644
--- a/tests/auto/qml/qjsengine/tst_qjsengine.cpp
+++ b/tests/auto/qml/qjsengine/tst_qjsengine.cpp
@@ -145,6 +145,7 @@ private slots:
     void array_join_QTBUG_53672();
 
     void regexpLastMatch();
+    void regexpLastIndex();
     void indexedAccesses();
 
     void prototypeChainGc();
@@ -3289,6 +3290,28 @@ void tst_QJSEngine::regexpLastMatch()
 
 }
 
+void tst_QJSEngine::regexpLastIndex()
+{
+    QJSEngine eng;
+    QJSValue result;
+    result = eng.evaluate("function test(text, rx) {"
+                          "    var res;"
+                          "    while (res = rx.exec(text)) { "
+                          "        return true;"
+                          "    }"
+                          "    return false;"
+                          " }"
+                          "function tester(text) {"
+                          "    return test(text, /,\\s*/g);"
+                          "}");
+    QVERIFY(!result.isError());
+
+    result = eng.evaluate("tester(\",  \\n\");");
+    QVERIFY(result.toBool());
+    result = eng.evaluate("tester(\",  \\n\");");
+    QVERIFY(result.toBool());
+}
+
 void tst_QJSEngine::indexedAccesses()
 {
     QJSEngine engine;
diff --git a/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp b/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp
index 1f80ff46d0..7e81df93b9 100644
--- a/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp
+++ b/tests/auto/qml/qmlcachegen/tst_qmlcachegen.cpp
@@ -44,6 +44,7 @@ private slots:
     void loadGeneratedFile();
     void translationExpressionSupport();
     void signalHandlerParameters();
+    void errorOnArgumentsInSignalHandler();
 };
 
 // A wrapper around QQmlComponent to ensure the temporary reference counts
@@ -68,15 +69,20 @@ public:
     }
 };
 
-static bool generateCache(const QString &qmlFileName)
+static bool generateCache(const QString &qmlFileName, QByteArray *capturedStderr = nullptr)
 {
     QProcess proc;
-    proc.setProcessChannelMode(QProcess::ForwardedChannels);
+    if (capturedStderr == nullptr)
+        proc.setProcessChannelMode(QProcess::ForwardedChannels);
     proc.setProgram(QLibraryInfo::location(QLibraryInfo::BinariesPath) + QDir::separator() + QLatin1String("qmlcachegen"));
     proc.setArguments(QStringList() << (QLatin1String("--target-architecture=") + QSysInfo::buildCpuArchitecture()) << (QLatin1String("--target-abi=") + QSysInfo::buildAbi()) << qmlFileName);
     proc.start();
     if (!proc.waitForFinished())
         return false;
+
+    if (capturedStderr)
+        *capturedStderr = proc.readAllStandardError();
+
     if (proc.exitStatus() != QProcess::NormalExit)
         return false;
     return proc.exitCode() == 0;
@@ -194,6 +200,31 @@ void tst_qmlcachegen::signalHandlerParameters()
     QCOMPARE(obj->property("result").toInt(), 42);
 }
 
+void tst_qmlcachegen::errorOnArgumentsInSignalHandler()
+{
+    QTemporaryDir tempDir;
+    QVERIFY(tempDir.isValid());
+
+    const auto writeTempFile = [&tempDir](const QString &fileName, const char *contents) {
+        QFile f(tempDir.path() + '/' + fileName);
+        const bool ok = f.open(QIODevice::WriteOnly | QIODevice::Truncate);
+        Q_ASSERT(ok);
+        f.write(contents);
+        return f.fileName();
+    };
+
+    const QString testFilePath = writeTempFile("test.qml", "import QtQml 2.2\n"
+                                                           "QtObject {\n"
+                                                           "    signal mySignal(var arguments);\n"
+                                                           "    onMySignal: console.log(arguments);\n"
+                                                           "}");
+
+
+    QByteArray errorOutput;
+    QVERIFY(!generateCache(testFilePath, &errorOutput));
+    QVERIFY2(errorOutput.contains("error: The use of the arguments object in signal handlers is"), errorOutput);
+}
+
 QTEST_GUILESS_MAIN(tst_qmlcachegen)
 
 #include "tst_qmlcachegen.moc"
diff --git a/tests/auto/qml/qmldiskcache/tst_qmldiskcache.cpp b/tests/auto/qml/qmldiskcache/tst_qmldiskcache.cpp
index 6ab84774f2..e75e51ed29 100644
--- a/tests/auto/qml/qmldiskcache/tst_qmldiskcache.cpp
+++ b/tests/auto/qml/qmldiskcache/tst_qmldiskcache.cpp
@@ -59,6 +59,7 @@ private slots:
     void cacheResources();
     void stableOrderOfDependentCompositeTypes();
     void singletonDependency();
+    void cppRegisteredSingletonDependency();
 };
 
 // A wrapper around QQmlComponent to ensure the temporary reference counts
@@ -790,6 +791,66 @@ void tst_qmldiskcache::singletonDependency()
     }
 }
 
+void tst_qmldiskcache::cppRegisteredSingletonDependency()
+{
+    qmlClearTypeRegistrations();
+    QScopedPointer<QQmlEngine> engine(new QQmlEngine);
+
+    QTemporaryDir tempDir;
+    QVERIFY(tempDir.isValid());
+
+    const auto writeTempFile = [&tempDir](const QString &fileName, const char *contents) {
+        QFile f(tempDir.path() + '/' + fileName);
+        const bool ok = f.open(QIODevice::WriteOnly | QIODevice::Truncate);
+        Q_ASSERT(ok);
+        f.write(contents);
+        return f.fileName();
+    };
+
+    writeTempFile("MySingleton.qml", "import QtQml 2.0\npragma Singleton\nQtObject { property int value: 42 }");
+
+    qmlRegisterSingletonType(QUrl::fromLocalFile(tempDir.path() + QLatin1String("/MySingleton.qml")), "CppRegisteredSingletonDependency", 1, 0, "Singly");
+
+    const QString testFilePath = writeTempFile("main.qml", "import QtQml 2.0\nimport CppRegisteredSingletonDependency 1.0\nQtObject {\n"
+                                                           "    function getValue() { return Singly.value; }\n"
+                                                           "}");
+
+    {
+        CleanlyLoadingComponent component(engine.data(), QUrl::fromLocalFile(testFilePath));
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+        QVariant value;
+        QVERIFY(QMetaObject::invokeMethod(obj.data(), "getValue", Q_RETURN_ARG(QVariant, value)));
+        QCOMPARE(value.toInt(), 42);
+    }
+
+    const QString testFileCachePath = testFilePath + QLatin1Char('c');
+    QVERIFY(QFile::exists(testFileCachePath));
+    QDateTime initialCacheTimeStamp = QFileInfo(testFileCachePath).lastModified();
+
+    engine.reset(new QQmlEngine);
+    waitForFileSystem();
+
+    writeTempFile("MySingleton.qml", "import QtQml 2.0\npragma Singleton\nQtObject { property int value: 100 }");
+    waitForFileSystem();
+
+    {
+        CleanlyLoadingComponent component(engine.data(), QUrl::fromLocalFile(testFilePath));
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+
+        {
+            QVERIFY(QFile::exists(testFileCachePath));
+            QDateTime newCacheTimeStamp = QFileInfo(testFileCachePath).lastModified();
+            QVERIFY2(newCacheTimeStamp > initialCacheTimeStamp, qPrintable(newCacheTimeStamp.toString()));
+        }
+
+        QVariant value;
+        QVERIFY(QMetaObject::invokeMethod(obj.data(), "getValue", Q_RETURN_ARG(QVariant, value)));
+        QCOMPARE(value.toInt(), 100);
+    }
+}
+
 QTEST_MAIN(tst_qmldiskcache)
 
 #include "tst_qmldiskcache.moc"
diff --git a/tests/auto/qml/qqmlcontext/data/Singleton.qml b/tests/auto/qml/qqmlcontext/data/Singleton.qml
new file mode 100644
index 0000000000..68ef5850e3
--- /dev/null
+++ b/tests/auto/qml/qqmlcontext/data/Singleton.qml
@@ -0,0 +1,5 @@
+pragma Singleton
+import QtQml 2.0
+QtObject {
+    readonly property string song: "Highway to Hell"
+}
diff --git a/tests/auto/qml/qqmlcontext/data/contextViaClosureAfterDestruction.qml b/tests/auto/qml/qqmlcontext/data/contextViaClosureAfterDestruction.qml
new file mode 100644
index 0000000000..2e0e6f20e2
--- /dev/null
+++ b/tests/auto/qml/qqmlcontext/data/contextViaClosureAfterDestruction.qml
@@ -0,0 +1,14 @@
+import QtQml 2.0
+
+import constants 1.0
+
+QtObject {
+    function createClosure() {
+        return function() { return Sing.song; }
+    }
+    function createComponentFactory() {
+        return function(parentObj) {
+            return Qt.createQmlObject('import QtQml 2.0; QtObject { property string test: "ok"; }', parentObj);
+        }
+    }
+}
diff --git a/tests/auto/qml/qqmlcontext/tst_qqmlcontext.cpp b/tests/auto/qml/qqmlcontext/tst_qqmlcontext.cpp
index f49fd391ac..5f57b9ebb0 100644
--- a/tests/auto/qml/qqmlcontext/tst_qqmlcontext.cpp
+++ b/tests/auto/qml/qqmlcontext/tst_qqmlcontext.cpp
@@ -62,6 +62,7 @@ private slots:
     void evalAfterInvalidate();
     void qobjectDerived();
     void qtbug_49232();
+    void contextViaClosureAfterDestruction();
 
 private:
     QQmlEngine engine;
@@ -723,6 +724,33 @@ void tst_qqmlcontext::qtbug_49232()
     QCOMPARE(obj->property("valueTwo"), QVariant(97));
 }
 
+void tst_qqmlcontext::contextViaClosureAfterDestruction()
+{
+    qmlRegisterSingletonType(testFileUrl("Singleton.qml"), "constants", 1, 0, "Sing");
+    QQmlEngine engine;
+    QQmlComponent component(&engine, testFileUrl("contextViaClosureAfterDestruction.qml"));
+    QJSValue valueClosure;
+    QJSValue componentFactoryClosure;
+    {
+        QScopedPointer<QObject> obj(component.create());
+        QVERIFY(!obj.isNull());
+        // meta-calls don't support QJSValue return types, so do the call "by hand"
+        valueClosure = engine.newQObject(obj.data()).property(QStringLiteral("createClosure")).call();
+        QVERIFY(valueClosure.isCallable());
+        componentFactoryClosure = engine.newQObject(obj.data()).property(QStringLiteral("createComponentFactory")).call();
+        QVERIFY(componentFactoryClosure.isCallable());
+    }
+    QCOMPARE(valueClosure.call().toString(), QLatin1String("Highway to Hell"));
+
+    QScopedPointer<QObject> parent(new QObject);
+    QJSValue parentWrapper = engine.newQObject(parent.data());
+    QQmlEngine::setObjectOwnership(parent.data(), QQmlEngine::CppOwnership);
+
+    QJSValue subObject = componentFactoryClosure.callWithInstance(componentFactoryClosure, QJSValueList() << parentWrapper);
+    QVERIFY(subObject.isError());
+    QCOMPARE(subObject.toString(), QLatin1String("Error: Qt.createQmlObject(): Cannot create a component in an invalid context"));
+}
+
 QTEST_MAIN(tst_qqmlcontext)
 
 #include "tst_qqmlcontext.moc"
diff --git a/tests/auto/qml/qqmlecmascript/testtypes.cpp b/tests/auto/qml/qqmlecmascript/testtypes.cpp
index c4692fdf31..80da5d7e52 100644
--- a/tests/auto/qml/qqmlecmascript/testtypes.cpp
+++ b/tests/auto/qml/qqmlecmascript/testtypes.cpp
@@ -245,9 +245,16 @@ public:
     MyWorkerObject *o;
 };
 
+MyWorkerObject::~MyWorkerObject()
+{
+    if (m_thread)
+        m_thread->wait();
+}
+
 void MyWorkerObject::doIt()
 {
-    new MyWorkerObjectThread(this);
+    Q_ASSERT(!m_thread);
+    m_thread = new MyWorkerObjectThread(this);
 }
 
 class MyDateClass : public QObject
diff --git a/tests/auto/qml/qqmlecmascript/testtypes.h b/tests/auto/qml/qqmlecmascript/testtypes.h
index eedeb66647..e15a05a00c 100644
--- a/tests/auto/qml/qqmlecmascript/testtypes.h
+++ b/tests/auto/qml/qqmlecmascript/testtypes.h
@@ -1532,12 +1532,17 @@ private:
 class MyWorkerObject : public QObject
 {
     Q_OBJECT
+public:
+    ~MyWorkerObject();
 
 public Q_SLOTS:
     void doIt();
 
 Q_SIGNALS:
     void done(const QString &result);
+
+private:
+    QThread *m_thread = 0;
 };
 
 class MyUnregisteredEnumTypeObject : public QObject
diff --git a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
index 45f312e934..35f1534478 100644
--- a/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
+++ b/tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp
@@ -7444,21 +7444,17 @@ void tst_qqmlecmascript::signalEmitted()
 void tst_qqmlecmascript::threadSignal()
 {
     {
-    QQmlComponent c(&engine, testFileUrl("threadSignal.qml"));
-    QObject *object = c.create();
-    QVERIFY(object != 0);
-    QTRY_VERIFY(object->property("passed").toBool());
-    delete object;
+        QQmlComponent c(&engine, testFileUrl("threadSignal.qml"));
+        QScopedPointer<QObject> object(c.create());
+        QVERIFY(!object.isNull());
+        QTRY_VERIFY(object->property("passed").toBool());
     }
     {
-    QQmlComponent c(&engine, testFileUrl("threadSignal.2.qml"));
-    QObject *object = c.create();
-    QVERIFY(object != 0);
-    QSignalSpy doneSpy(object, SIGNAL(done(QString)));
-    QMetaObject::invokeMethod(object, "doIt");
-    QTRY_VERIFY(object->property("passed").toBool());
-    QCOMPARE(doneSpy.count(), 1);
-    delete object;
+        QQmlComponent c(&engine, testFileUrl("threadSignal.2.qml"));
+        QScopedPointer<QObject> object(c.create());
+        QVERIFY(!object.isNull());
+        QMetaObject::invokeMethod(object.data(), "doIt");
+        QTRY_VERIFY(object->property("passed").toBool());
     }
 }
 
diff --git a/tests/auto/qml/qqmlenginecleanup/qqmlenginecleanup.pro b/tests/auto/qml/qqmlenginecleanup/qqmlenginecleanup.pro
index 5bcec9f5b4..90508609a8 100644
--- a/tests/auto/qml/qqmlenginecleanup/qqmlenginecleanup.pro
+++ b/tests/auto/qml/qqmlenginecleanup/qqmlenginecleanup.pro
@@ -6,4 +6,4 @@ include (../../shared/util.pri)
 
 SOURCES += tst_qqmlenginecleanup.cpp
 
-QT += testlib qml
+QT += testlib qml qml-private
diff --git a/tests/auto/qml/qqmlenginecleanup/tst_qqmlenginecleanup.cpp b/tests/auto/qml/qqmlenginecleanup/tst_qqmlenginecleanup.cpp
index d0a8b6401f..7e9a1524b0 100644
--- a/tests/auto/qml/qqmlenginecleanup/tst_qqmlenginecleanup.cpp
+++ b/tests/auto/qml/qqmlenginecleanup/tst_qqmlenginecleanup.cpp
@@ -31,6 +31,8 @@
 #include <QtQml/qqml.h>
 #include <QtQml/QQmlEngine>
 #include <QtQml/QQmlComponent>
+#include <private/qhashedstring_p.h>
+#include <private/qqmlmetatype_p.h>
 
 //Separate test, because if engine cleanup attempts fail they can easily break unrelated tests
 class tst_qqmlenginecleanup : public QQmlDataTest
@@ -44,41 +46,82 @@ private slots:
     void test_valueTypeProviderModule(); // QTBUG-43004
 };
 
+// A wrapper around QQmlComponent to ensure the temporary reference counts
+// on the type data as a result of the main thread <> loader thread communication
+// are dropped. Regular Synchronous loading will leave us with an event posted
+// to the gui thread and an extra refcount that will only be dropped after the
+// event delivery. A plain sendPostedEvents() however is insufficient because
+// we can't be sure that the event is posted after the constructor finished.
+class CleanlyLoadingComponent : public QQmlComponent
+{
+public:
+    CleanlyLoadingComponent(QQmlEngine *engine, const QUrl &url)
+        : QQmlComponent(engine, url, QQmlComponent::Asynchronous)
+    { waitForLoad(); }
+    CleanlyLoadingComponent(QQmlEngine *engine, const QString &fileName)
+        : QQmlComponent(engine, fileName, QQmlComponent::Asynchronous)
+    { waitForLoad(); }
+
+    void waitForLoad()
+    {
+        QTRY_VERIFY(status() == QQmlComponent::Ready || status() == QQmlComponent::Error);
+    }
+};
+
 void tst_qqmlenginecleanup::test_qmlClearTypeRegistrations()
 {
     //Test for preventing memory leaks is in tests/manual/qmltypememory
     QQmlEngine* engine;
-    QQmlComponent* component;
+    CleanlyLoadingComponent* component;
     QUrl testFile = testFileUrl("types.qml");
 
+    const auto qmlTypeForTestType = []() {
+        return QQmlMetaType::qmlType(QStringLiteral("TestTypeCpp"), QStringLiteral("Test"), 2, 0);
+    };
+
+    QVERIFY(!qmlTypeForTestType().isValid());
     qmlRegisterType<QObject>("Test", 2, 0, "TestTypeCpp");
+    QVERIFY(qmlTypeForTestType().isValid());
+
     engine = new QQmlEngine;
-    component = new QQmlComponent(engine, testFile);
+    component = new CleanlyLoadingComponent(engine, testFile);
     QVERIFY(component->isReady());
 
-    delete engine;
     delete component;
-    qmlClearTypeRegistrations();
+    delete engine;
+
+    {
+        auto cppType = qmlTypeForTestType();
+
+        qmlClearTypeRegistrations();
+        QVERIFY(!qmlTypeForTestType().isValid());
+
+        // cppType should hold the last ref, qmlClearTypeRegistration should have wiped
+        // all internal references.
+        QCOMPARE(QQmlType::refCount(cppType.priv()), 1);
+    }
 
     //2nd run verifies that types can reload after a qmlClearTypeRegistrations
     qmlRegisterType<QObject>("Test", 2, 0, "TestTypeCpp");
+    QVERIFY(qmlTypeForTestType().isValid());
     engine = new QQmlEngine;
-    component = new QQmlComponent(engine, testFile);
+    component = new CleanlyLoadingComponent(engine, testFile);
     QVERIFY(component->isReady());
 
-    delete engine;
     delete component;
+    delete engine;
     qmlClearTypeRegistrations();
+    QVERIFY(!qmlTypeForTestType().isValid());
 
     //3nd run verifies that TestTypeCpp is no longer registered
     engine = new QQmlEngine;
-    component = new QQmlComponent(engine, testFile);
+    component = new CleanlyLoadingComponent(engine, testFile);
     QVERIFY(component->isError());
     QCOMPARE(component->errorString(),
             testFile.toString() +":33 module \"Test\" is not installed\n");
 
-    delete engine;
     delete component;
+    delete engine;
 }
 
 static void cleanState(QQmlEngine **e)
diff --git a/tests/auto/qml/qqmllanguage/data/MyLazyDeferredSubObject.qml b/tests/auto/qml/qqmllanguage/data/MyLazyDeferredSubObject.qml
new file mode 100644
index 0000000000..f311f6b602
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/MyLazyDeferredSubObject.qml
@@ -0,0 +1,6 @@
+import QtQml 2.0
+import Test 1.0
+LazyDeferredSubObject {
+    subObject: QtObject { objectName: 'default' }
+    objectName: subObject.objectName
+}
diff --git a/tests/auto/qml/qqmllanguage/data/lazyDeferredSubObject.qml b/tests/auto/qml/qqmllanguage/data/lazyDeferredSubObject.qml
new file mode 100644
index 0000000000..2465a18320
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/lazyDeferredSubObject.qml
@@ -0,0 +1,5 @@
+import QtQml 2.0
+import Test 1.0
+MyLazyDeferredSubObject {
+    subObject.objectName: 'custom'
+}
diff --git a/tests/auto/qml/qqmllanguage/testtypes.cpp b/tests/auto/qml/qqmllanguage/testtypes.cpp
index bdcdaa8137..72e06d26aa 100644
--- a/tests/auto/qml/qqmllanguage/testtypes.cpp
+++ b/tests/auto/qml/qqmllanguage/testtypes.cpp
@@ -103,6 +103,8 @@ void registerTypes()
     qmlRegisterSingletonType<MyTypeObjectSingleton>("Test", 1, 0, "MyTypeObjectSingleton", myTypeObjectSingleton);
 
     qmlRegisterType<MyArrayBufferTestClass>("Test", 1, 0, "MyArrayBufferTestClass");
+
+    qmlRegisterType<LazyDeferredSubObject>("Test", 1, 0, "LazyDeferredSubObject");
 }
 
 QVariant myCustomVariantTypeConverter(const QString &data)
diff --git a/tests/auto/qml/qqmllanguage/testtypes.h b/tests/auto/qml/qqmllanguage/testtypes.h
index e4a76b4324..09c6992a51 100644
--- a/tests/auto/qml/qqmllanguage/testtypes.h
+++ b/tests/auto/qml/qqmllanguage/testtypes.h
@@ -1349,6 +1349,26 @@ private:
     QObject *obj;
 };
 
+class LazyDeferredSubObject : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QObject *subObject READ subObject WRITE setSubObject NOTIFY subObjectChanged FINAL)
+    Q_CLASSINFO("DeferredPropertyNames", "subObject");
+public:
+    LazyDeferredSubObject()
+        : obj(0)
+    {}
+
+    QObject *subObject() const { if (!obj) qmlExecuteDeferred(const_cast<LazyDeferredSubObject *>(this)); return obj; }
+    void setSubObject(QObject *o) { if (obj == o) return; obj = o; emit subObjectChanged(); }
+
+signals:
+    void subObjectChanged();
+
+private:
+    QObject *obj;
+};
+
 void registerTypes();
 
 #endif // TESTTYPES_H
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index f09c130e38..e5366b5c48 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -250,6 +250,7 @@ private slots:
     void propertyCacheInSync();
 
     void rootObjectInCreationNotForSubObjects();
+    void lazyDeferredSubObject();
 
     void noChildEvents();
 
@@ -2152,7 +2153,7 @@ void tst_qqmllanguage::scriptStringWithoutSourceCode()
         qmlUnit->flags &= ~QV4::CompiledData::Unit::StaticData;
         td->compilationUnit()->data = qmlUnit;
 
-        const QV4::CompiledData::Object *rootObject = qmlUnit->objectAt(qmlUnit->indexOfRootObject);
+        const QV4::CompiledData::Object *rootObject = qmlUnit->objectAt(/*root object*/0);
         QCOMPARE(qmlUnit->stringAt(rootObject->inheritedTypeNameIndex), QString("MyTypeObject"));
         quint32 i;
         for (i = 0; i < rootObject->nBindings; ++i) {
@@ -4314,6 +4315,21 @@ void tst_qqmllanguage::rootObjectInCreationNotForSubObjects()
     QVERIFY(!ddata->rootObjectInCreation);
 }
 
+// QTBUG-63036
+void tst_qqmllanguage::lazyDeferredSubObject()
+{
+    QQmlComponent component(&engine, testFile("lazyDeferredSubObject.qml"));
+    VERIFY_ERRORS(0);
+    QScopedPointer<QObject> object(component.create());
+    QVERIFY(!object.isNull());
+
+    QObject *subObject = qvariant_cast<QObject *>(object->property("subObject"));
+    QVERIFY(subObject);
+
+    QCOMPARE(object->objectName(), QStringLiteral("custom"));
+    QCOMPARE(subObject->objectName(), QStringLiteral("custom"));
+}
+
 void tst_qqmllanguage::noChildEvents()
 {
     QQmlComponent component(&engine);
diff --git a/tests/auto/qml/qqmllistmodel/tst_qqmllistmodel.cpp b/tests/auto/qml/qqmllistmodel/tst_qqmllistmodel.cpp
index e442dd1421..4089673d68 100644
--- a/tests/auto/qml/qqmllistmodel/tst_qqmllistmodel.cpp
+++ b/tests/auto/qml/qqmllistmodel/tst_qqmllistmodel.cpp
@@ -123,6 +123,7 @@ private slots:
     void about_to_be_signals();
     void modify_through_delegate();
     void bindingsOnGetResult();
+    void stringifyModelEntry();
 };
 
 bool tst_qqmllistmodel::compareVariantList(const QVariantList &testList, QVariant object)
@@ -1482,6 +1483,28 @@ void tst_qqmllistmodel::bindingsOnGetResult()
     QVERIFY(obj->property("success").toBool());
 }
 
+void tst_qqmllistmodel::stringifyModelEntry()
+{
+    QQmlEngine engine;
+    QQmlComponent component(&engine);
+    component.setData(
+                      "import QtQuick 2.0\n"
+                      "Item {\n"
+                      "   ListModel {\n"
+                      "       id: testModel\n"
+                      "       objectName: \"testModel\"\n"
+                      "       ListElement { name: \"Joe\"; age: 22 }\n"
+                      "   }\n"
+                      "}\n", QUrl());
+    QScopedPointer<QObject> scene(component.create());
+    QQmlListModel *model = scene->findChild<QQmlListModel*>("testModel");
+    QQmlExpression expr(engine.rootContext(), model, "JSON.stringify(get(0));");
+    QVariant v = expr.evaluate();
+    QVERIFY2(!expr.hasError(), QTest::toString(expr.error().toString()));
+    const QString expectedString = QStringLiteral("{\"age\":22,\"name\":\"Joe\"}");
+    QCOMPARE(v.toString(), expectedString);
+}
+
 QTEST_MAIN(tst_qqmllistmodel)
 
 #include "tst_qqmllistmodel.moc"
diff --git a/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp b/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
index 1c9523fc38..80c54bdf8e 100644
--- a/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
+++ b/tests/auto/qml/qqmltranslation/tst_qqmltranslation.cpp
@@ -86,7 +86,7 @@ void tst_qqmltranslation::translation()
                              << QStringLiteral("singular") << QStringLiteral("plural");
 
         const QV4::CompiledData::Unit *unit = compilationUnit->data;
-        const QV4::CompiledData::Object *rootObject = unit->objectAt(unit->indexOfRootObject);
+        const QV4::CompiledData::Object *rootObject = unit->objectAt(/*root object*/0);
         const QV4::CompiledData::Binding *binding = rootObject->bindingTable();
         for (quint32 i = 0; i < rootObject->nBindings; ++i, ++binding) {
             const QString propertyName = unit->stringAt(binding->propertyNameIndex);
@@ -141,7 +141,7 @@ void tst_qqmltranslation::idTranslation()
         QVERIFY(compilationUnit);
 
         const QV4::CompiledData::Unit *unit = compilationUnit->data;
-        const QV4::CompiledData::Object *rootObject = unit->objectAt(unit->indexOfRootObject);
+        const QV4::CompiledData::Object *rootObject = unit->objectAt(/*root object*/0);
         const QV4::CompiledData::Binding *binding = rootObject->bindingTable();
         for (quint32 i = 0; i < rootObject->nBindings; ++i, ++binding) {
             const QString propertyName = unit->stringAt(binding->propertyNameIndex);
diff --git a/tests/auto/quick/qquickanimatedimage/tst_qquickanimatedimage.cpp b/tests/auto/quick/qquickanimatedimage/tst_qquickanimatedimage.cpp
index 34b9fb6b07..e303495944 100644
--- a/tests/auto/quick/qquickanimatedimage/tst_qquickanimatedimage.cpp
+++ b/tests/auto/quick/qquickanimatedimage/tst_qquickanimatedimage.cpp
@@ -132,6 +132,16 @@ void tst_qquickanimatedimage::frameCount()
     QVERIFY(anim->isPlaying());
     QCOMPARE(anim->frameCount(), 3);
 
+    QSignalSpy frameCountChangedSpy(anim, &QQuickAnimatedImage::frameCountChanged);
+
+    const QUrl origSource = anim->source();
+    anim->setSource(QUrl());
+    QCOMPARE(anim->frameCount(), 0);
+    QCOMPARE(frameCountChangedSpy.count(), 1);
+    anim->setSource(origSource);
+    QCOMPARE(anim->frameCount(), 3);
+    QCOMPARE(frameCountChangedSpy.count(), 2);
+
     delete anim;
 }
 
diff --git a/tests/auto/quick/qquickgridview/tst_qquickgridview.cpp b/tests/auto/quick/qquickgridview/tst_qquickgridview.cpp
index b2d6584701..2b14842658 100644
--- a/tests/auto/quick/qquickgridview/tst_qquickgridview.cpp
+++ b/tests/auto/quick/qquickgridview/tst_qquickgridview.cpp
@@ -46,6 +46,8 @@
 #include <QtGui/qguiapplication.h>
 #include "qplatformdefs.h"
 
+#include <math.h>
+
 Q_DECLARE_METATYPE(QQuickGridView::Flow)
 Q_DECLARE_METATYPE(Qt::LayoutDirection)
 Q_DECLARE_METATYPE(QQuickItemView::VerticalLayoutDirection)
diff --git a/tests/auto/quick/qquicklistview/data/programmaticFlickAtBounds3.qml b/tests/auto/quick/qquicklistview/data/programmaticFlickAtBounds3.qml
new file mode 100644
index 0000000000..bd913b2ce1
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/data/programmaticFlickAtBounds3.qml
@@ -0,0 +1,19 @@
+import QtQuick 2.9
+
+ListView {
+    id: view
+    width: 200; height: 400
+
+    property real minOvershoot
+    onVerticalOvershootChanged: if (verticalOvershoot < minOvershoot) minOvershoot = verticalOvershoot
+
+    highlightRangeMode: ListView.StrictlyEnforceRange
+    preferredHighlightBegin: 0
+    preferredHighlightEnd: 0
+
+    model: 10
+    delegate: Rectangle {
+        width: 200; height: 50
+        color: index % 2 ? "red" : "green"
+    }
+}
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index 2eb87b9431..0d0f234d33 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -236,6 +236,7 @@ private slots:
     void QTBUG_38209();
     void programmaticFlickAtBounds();
     void programmaticFlickAtBounds2();
+    void programmaticFlickAtBounds3();
 
     void layoutChange();
 
@@ -8069,6 +8070,35 @@ void tst_QQuickListView::programmaticFlickAtBounds2()
     QTRY_COMPARE(listview->contentY(), qreal(100.0));
 }
 
+void tst_QQuickListView::programmaticFlickAtBounds3()
+{
+    QScopedPointer<QQuickView> window(createView());
+    window->setSource(testFileUrl("programmaticFlickAtBounds3.qml"));
+    window->show();
+    QVERIFY(QTest::qWaitForWindowExposed(window.data()));
+
+    QQuickListView *listview = qobject_cast<QQuickListView *>(window->rootObject());
+    QVERIFY(listview);
+
+    // flick down
+    listview->flick(0, 2000);
+
+    // verify scope of the movement
+    QTRY_VERIFY(listview->property("minOvershoot").toReal() < qreal(-50.0));
+
+    // reset, and test a second time
+    listview->cancelFlick();
+    listview->returnToBounds();
+    QTRY_COMPARE(listview->contentY(), qreal(0.0));
+    listview->setProperty("minOvershoot", qreal(0.0));
+
+    // flick down
+    listview->flick(0, 2000);
+
+    // verify scope of the movement is the same
+    QTRY_VERIFY(listview->property("minOvershoot").toReal() < qreal(-50.0));
+}
+
 void tst_QQuickListView::layoutChange()
 {
     RandomSortModel *model = new RandomSortModel;
diff --git a/tests/auto/quick/qquickmultipointtoucharea/data/nonOverlapping.qml b/tests/auto/quick/qquickmultipointtoucharea/data/nonOverlapping.qml
index 039607e26c..027f90c7f4 100644
--- a/tests/auto/quick/qquickmultipointtoucharea/data/nonOverlapping.qml
+++ b/tests/auto/quick/qquickmultipointtoucharea/data/nonOverlapping.qml
@@ -11,9 +11,21 @@ Rectangle {
         maximumTouchPoints: 2
         onGestureStarted: gesture.grab()
         touchPoints: [
-            TouchPoint { objectName: "point11" },
-            TouchPoint { objectName: "point12" }
+            TouchPoint { id: point11; objectName: "point11" },
+            TouchPoint { id: point12; objectName: "point12" }
         ]
+        Rectangle {
+            color: "red"
+            width: 10; height: 10; radius: 5
+            x: point11.x - radius; y: point11.y - radius
+            visible: point11.pressed
+        }
+        Rectangle {
+            color: "tomato"
+            width: 10; height: 10; radius: 5
+            x: point12.x - radius; y: point12.y - radius
+            visible: point12.pressed
+        }
     }
 
     MultiPointTouchArea {
@@ -24,9 +36,27 @@ Rectangle {
         maximumTouchPoints: 3
         onGestureStarted: gesture.grab()
         touchPoints: [
-            TouchPoint { objectName: "point21" },
-            TouchPoint { objectName: "point22" },
-            TouchPoint { objectName: "point23" }
+            TouchPoint { id: point21; objectName: "point21" },
+            TouchPoint { id: point22; objectName: "point22" },
+            TouchPoint { id: point23; objectName: "point23" }
         ]
+        Rectangle {
+            color: "lightgreen"
+            width: 10; height: 10; radius: 5
+            x: point21.x - radius; y: point21.y - radius
+            visible: point21.pressed
+        }
+        Rectangle {
+            color: "green"
+            width: 10; height: 10; radius: 5
+            x: point22.x - radius; y: point22.y - radius
+            visible: point22.pressed
+        }
+        Rectangle {
+            color: "darkgreen"
+            width: 10; height: 10; radius: 5
+            x: point23.x - radius; y: point23.y - radius
+            visible: point23.pressed
+        }
     }
 }
diff --git a/tests/auto/quick/qquickpathview/tst_qquickpathview.cpp b/tests/auto/quick/qquickpathview/tst_qquickpathview.cpp
index b01d0c3cec..cbef0fcc8d 100644
--- a/tests/auto/quick/qquickpathview/tst_qquickpathview.cpp
+++ b/tests/auto/quick/qquickpathview/tst_qquickpathview.cpp
@@ -48,6 +48,8 @@
 #include "../shared/viewtestutil.h"
 #include "../shared/visualtestutil.h"
 
+#include <math.h>
+
 using namespace QQuickViewTestUtil;
 using namespace QQuickVisualTestUtil;
 
diff --git a/tests/auto/quick/qquicktextedit/tst_qquicktextedit.cpp b/tests/auto/quick/qquicktextedit/tst_qquicktextedit.cpp
index ac57a05176..d58fc6c389 100644
--- a/tests/auto/quick/qquicktextedit/tst_qquicktextedit.cpp
+++ b/tests/auto/quick/qquicktextedit/tst_qquicktextedit.cpp
@@ -158,6 +158,7 @@ private slots:
 #endif
     void implicitSize_data();
     void implicitSize();
+    void implicitSize_QTBUG_63153();
     void contentSize();
     void boundingRect();
     void clipRect();
@@ -3388,6 +3389,18 @@ void tst_qquicktextedit::implicitSize()
     QCOMPARE(textObject->height(), textObject->implicitHeight());
 }
 
+void tst_qquicktextedit::implicitSize_QTBUG_63153()
+{
+    QString componentStr = "import QtQuick 2.0\nTextEdit { }";
+    QQmlComponent textComponent(&engine);
+    textComponent.setData(componentStr.toLatin1(), QUrl::fromLocalFile(""));
+    QQuickTextEdit *textObject = qobject_cast<QQuickTextEdit*>(textComponent.create());
+    textObject->setText("short");
+    qreal shortImplicitWidth = textObject->implicitWidth();
+    textObject->setText("in contrast to short this is long");
+    QVERIFY2(shortImplicitWidth < textObject->implicitWidth(), qPrintable(QString("%1 < %2").arg(textObject->implicitWidth()).arg(shortImplicitWidth)));
+}
+
 void tst_qquicktextedit::contentSize()
 {
     QString componentStr = "import QtQuick 2.0\nTextEdit { width: 75; height: 16; font.pixelSize: 10 }";
diff --git a/tools/qmlcachegen/qmlcachegen.cpp b/tools/qmlcachegen/qmlcachegen.cpp
index b201176d5e..a62adc82f4 100644
--- a/tools/qmlcachegen/qmlcachegen.cpp
+++ b/tools/qmlcachegen/qmlcachegen.cpp
@@ -114,6 +114,37 @@ static void annotateListElements(QmlIR::Document *document)
     }
 }
 
+static bool checkArgumentsObjectUseInSignalHandlers(const QmlIR::Document &doc, Error *error)
+{
+    for (QmlIR::Object *object: qAsConst(doc.objects)) {
+        for (auto binding = object->bindingsBegin(); binding != object->bindingsEnd(); ++binding) {
+            if (binding->type != QV4::CompiledData::Binding::Type_Script)
+                continue;
+            const QString propName =  doc.stringAt(binding->propertyNameIndex);
+            if (!propName.startsWith(QLatin1String("on"))
+                || propName.length() < 3
+                || !propName.at(2).isUpper())
+                continue;
+            auto compiledFunction = doc.jsModule.functions.value(object->runtimeFunctionIndices.at(binding->value.compiledScriptIndex));
+            if (!compiledFunction)
+                continue;
+            if (compiledFunction->usesArgumentsObject) {
+                error->message = QLatin1Char(':') + QString::number(compiledFunction->line) + QLatin1Char(':');
+                if (compiledFunction->column > 0)
+                    error->message += QString::number(compiledFunction->column) + QLatin1Char(':');
+
+                error->message += QLatin1String(" error: The use of the arguments object in signal handlers is\n"
+                                                "not supported when compiling qml files ahead of time, because it may be ambiguous if\n"
+                                                "any signal parameter is called \"arguments\". Unfortunately we cannot distinguish\n"
+                                                "between it being a parameter or the JavaScript arguments object at this point.\n"
+                                                "Consider renaming the parameter of the signal if applicable.");
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
 static bool compileQmlFile(const QString &inputFileName, const QString &outputFileName, QV4::EvalISelFactory *iselFactory, const QString &targetABI, Error *error)
 {
     QmlIR::Document irDocument(/*debugMode*/false);
@@ -173,6 +204,11 @@ static bool compileQmlFile(const QString &inputFileName, const QString &outputFi
             object->runtimeFunctionIndices.allocate(pool, runtimeFunctionIndices);
         }
 
+        if (!checkArgumentsObjectUseInSignalHandlers(irDocument, error)) {
+            *error = error->augment(inputFileName);
+            return false;
+        }
+
         QmlIR::QmlUnitGenerator generator;
 
         {
diff --git a/tools/qmlimportscanner/main.cpp b/tools/qmlimportscanner/main.cpp
index 9ab058d37b..d596613553 100644
--- a/tools/qmlimportscanner/main.cpp
+++ b/tools/qmlimportscanner/main.cpp
@@ -404,7 +404,7 @@ QVariantList findQmlImportsInDirectory(const QString &qmlDir)
     if (qmlDir.isEmpty())
         return ret;
 
-    QDirIterator iterator(qmlDir, QDir::AllDirs | QDir::NoDot | QDir::NoDotDot, QDirIterator::Subdirectories);
+    QDirIterator iterator(qmlDir, QDir::AllDirs | QDir::NoDotDot, QDirIterator::Subdirectories);
     QStringList blacklist;
 
     while (iterator.hasNext()) {
diff --git a/tools/qmlplugindump/main.cpp b/tools/qmlplugindump/main.cpp
index 79f9b2c49b..422e37fd89 100644
--- a/tools/qmlplugindump/main.cpp
+++ b/tools/qmlplugindump/main.cpp
@@ -788,7 +788,7 @@ static bool readDependenciesData(QString dependenciesFile, const QByteArray &fil
                 QString version = obj.value(QStringLiteral("version")).toString();
                 if (name.isEmpty() || urisToSkip.contains(name) || version.isEmpty())
                     continue;
-                if (name.endsWith(QLatin1String("Private"), Qt::CaseInsensitive)) {
+                if (name.contains(QLatin1String("Private"), Qt::CaseInsensitive)) {
                     if (verbose)
                         std::cerr << "skipping private dependecy "
                                   << qPrintable( name ) << " "  << qPrintable(version) << std::endl;