20 files changed, 209 insertions, 140 deletions

diff --git a/src/widgets/dialogs/qcolordialog.cpp b/src/widgets/dialogs/qcolordialog.cpp
index 8a1bd1431e..82c341b47c 100644
--- a/src/widgets/dialogs/qcolordialog.cpp
+++ b/src/widgets/dialogs/qcolordialog.cpp
@@ -57,6 +57,11 @@
 #include "qpainter.h"
 #include "qpixmap.h"
 #include "qpushbutton.h"
+#if QT_CONFIG(regularexpression)
+#include <qregularexpression.h>
+#else
+#include <qregexp.h>
+#endif
 #if QT_CONFIG(settings)
 #include "qsettings.h"
 #endif
@@ -1616,7 +1621,7 @@ void QColorDialogPrivate::_q_pickScreenColor()
     q->grabMouse();
 #endif
 
-#ifdef Q_OS_WIN32 // excludes WinCE and WinRT
+#ifdef Q_OS_WIN32 // excludes WinRT
     // On Windows mouse tracking doesn't work over other processes's windows
     updateTimer->start(30);
 
diff --git a/src/widgets/dialogs/qdialog.cpp b/src/widgets/dialogs/qdialog.cpp
index caab6c16ba..3cdd9a5f04 100644
--- a/src/widgets/dialogs/qdialog.cpp
+++ b/src/widgets/dialogs/qdialog.cpp
@@ -270,12 +270,11 @@ void QDialogPrivate::deletePlatformHelper()
 
     The most common way to display a modal dialog is to call its
     exec() function. When the user closes the dialog, exec() will
-    provide a useful \l{#return}{return value}. Typically,
-    to get the dialog to close and return the appropriate value, we
-    connect a default button, e.g. \uicontrol OK, to the accept() slot and a
-    \uicontrol Cancel button to the reject() slot.
-    Alternatively you can call the done() slot with \c Accepted or
-    \c Rejected.
+    provide a useful \l{#return}{return value}. To close the dialog
+    and return the appropriate value, you must connect a default button,
+    e.g. an \uicontrol OK button to the accept() slot and a
+    \uicontrol Cancel button to the reject() slot. Alternatively, you
+    can call the done() slot with \c Accepted or \c Rejected.
 
     An alternative is to call setModal(true) or setWindowModality(),
     then show(). Unlike exec(), show() returns control to the caller
@@ -283,7 +282,7 @@ void QDialogPrivate::deletePlatformHelper()
     progress dialogs, where the user must have the ability to interact
     with the dialog, e.g.  to cancel a long running operation. If you
     use show() and setModal(true) together to perform a long operation,
-    you must call QApplication::processEvents() periodically during
+    you must call QCoreApplication::processEvents() periodically during
     processing to enable the user to interact with the dialog. (See
     QProgressDialog.)
 
@@ -692,7 +691,7 @@ void QDialog::contextMenuEvent(QContextMenuEvent *e)
         if (p.data()->exec(e->globalPos()) == wt) {
             QHelpEvent e(QEvent::WhatsThis, w->rect().center(),
                          w->mapToGlobal(w->rect().center()));
-            QApplication::sendEvent(w, &e);
+            QCoreApplication::sendEvent(w, &e);
         }
         delete p.data();
     }
@@ -827,7 +826,7 @@ QT_WARNING_POP
 #endif
         if (fw && !fw->hasFocus()) {
             QFocusEvent e(QEvent::FocusIn, Qt::TabFocusReason);
-            QApplication::sendEvent(fw, &e);
+            QCoreApplication::sendEvent(fw, &e);
         }
 
 #ifndef QT_NO_ACCESSIBILITY
diff --git a/src/widgets/dialogs/qdialog_p.h b/src/widgets/dialogs/qdialog_p.h
index 92634f6793..74f775a0bd 100644
--- a/src/widgets/dialogs/qdialog_p.h
+++ b/src/widgets/dialogs/qdialog_p.h
@@ -75,15 +75,15 @@ public:
     QDialogPrivate()
         :
 #if QT_CONFIG(pushbutton)
-          mainDef(0),
+          mainDef(nullptr),
 #endif
-          orientation(Qt::Horizontal),extension(0), doShowExtension(false),
+          orientation(Qt::Horizontal),extension(nullptr), doShowExtension(false),
 #if QT_CONFIG(sizegrip)
-          resizer(0),
+          resizer(nullptr),
           sizeGripEnabled(false),
 #endif
-          rescode(0), resetModalityTo(-1), wasModalitySet(true), eventLoop(0),
-          nativeDialogInUse(false), m_platformHelper(0), m_platformHelperCreated(false)
+          rescode(0), resetModalityTo(-1), wasModalitySet(true), eventLoop(nullptr),
+          nativeDialogInUse(false), m_platformHelper(nullptr), m_platformHelperCreated(false)
         {}
     ~QDialogPrivate();
 
@@ -140,14 +140,14 @@ class QAutoPointer {
     struct internal { void func() {} };
     typedef void (internal::*RestrictedBool)();
 public:
-    explicit QAutoPointer(T *t) Q_DECL_NOTHROW : o(t) {}
+    explicit QAutoPointer(T *t) noexcept : o(t) {}
     ~QAutoPointer() { delete o; }
 
-    T *operator->() const Q_DECL_NOTHROW { return get(); }
-    T *get() const Q_DECL_NOTHROW { return o; }
+    T *operator->() const noexcept { return get(); }
+    T *get() const noexcept { return o; }
     T &operator*() const { return *get(); }
-    operator RestrictedBool() const Q_DECL_NOTHROW { return o ? &internal::func : nullptr; }
-    bool operator!() const Q_DECL_NOTHROW { return !o; }
+    operator RestrictedBool() const noexcept { return o ? &internal::func : nullptr; }
+    bool operator!() const noexcept { return !o; }
 private:
     Q_DISABLE_COPY(QAutoPointer);
 };
diff --git a/src/widgets/dialogs/qerrormessage.cpp b/src/widgets/dialogs/qerrormessage.cpp
index fd68f19680..f0ec2c0102 100644
--- a/src/widgets/dialogs/qerrormessage.cpp
+++ b/src/widgets/dialogs/qerrormessage.cpp
@@ -295,7 +295,7 @@ QErrorMessage * QErrorMessage::qtHandler()
     if (!qtMessageHandler) {
         qtMessageHandler = new QErrorMessage(0);
         qAddPostRoutine(deleteStaticcQErrorMessage); // clean up
-        qtMessageHandler->setWindowTitle(QApplication::applicationName());
+        qtMessageHandler->setWindowTitle(QCoreApplication::applicationName());
         qInstallMessageHandler(jump);
     }
     return qtMessageHandler;
@@ -322,8 +322,8 @@ bool QErrorMessagePrivate::nextPending()
 #else
             errors->setPlainText(message);
 #endif
-            currentMessage = qMove(message);
-            currentType = qMove(type);
+            currentMessage = std::move(message);
+            currentType = std::move(type);
             return true;
         }
     }
diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index f772eb1241..2f45635298 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -77,6 +77,8 @@
 #include <private/qwasmlocalfileaccess_p.h>
 #endif
 
+#include <algorithm>
+
 QT_BEGIN_NAMESPACE
 
 Q_GLOBAL_STATIC(QUrl, lastVisitedDir)
@@ -3372,6 +3374,18 @@ void QFileDialogPrivate::_q_goHome()
     q->setDirectory(QDir::homePath());
 }
 
+
+void QFileDialogPrivate::saveHistorySelection()
+{
+    if (qFileDialogUi.isNull() || currentHistoryLocation < 0 || currentHistoryLocation >= currentHistory.size())
+        return;
+    auto &item = currentHistory[currentHistoryLocation];
+    item.selection.clear();
+    const auto selectedIndexes = qFileDialogUi->listView->selectionModel()->selectedRows();
+    for (const auto &index : selectedIndexes)
+        item.selection.append(QPersistentModelIndex(index));
+}
+
 /*!
     \internal
 
@@ -3385,17 +3399,49 @@ void QFileDialogPrivate::_q_pathChanged(const QString &newPath)
     qFileDialogUi->sidebar->selectUrl(QUrl::fromLocalFile(newPath));
     q->setHistory(qFileDialogUi->lookInCombo->history());
 
-    if (currentHistoryLocation < 0 || currentHistory.value(currentHistoryLocation) != QDir::toNativeSeparators(newPath)) {
+    const QString newNativePath = QDir::toNativeSeparators(newPath);
+
+    // equal paths indicate this was invoked by _q_navigateBack/Forward()
+    if (currentHistoryLocation < 0 || currentHistory.value(currentHistoryLocation).path != newNativePath) {
+        if (currentHistoryLocation >= 0)
+            saveHistorySelection();
         while (currentHistoryLocation >= 0 && currentHistoryLocation + 1 < currentHistory.count()) {
             currentHistory.removeLast();
         }
-        currentHistory.append(QDir::toNativeSeparators(newPath));
+        currentHistory.append({newNativePath, PersistentModelIndexList()});
         ++currentHistoryLocation;
     }
     qFileDialogUi->forwardButton->setEnabled(currentHistory.size() - currentHistoryLocation > 1);
     qFileDialogUi->backButton->setEnabled(currentHistoryLocation > 0);
 }
 
+void QFileDialogPrivate::navigate(HistoryItem &historyItem)
+{
+    Q_Q(QFileDialog);
+    q->setDirectory(historyItem.path);
+    // Restore selection unless something has changed in the file system
+    if (qFileDialogUi.isNull() || historyItem.selection.isEmpty())
+        return;
+    if (std::any_of(historyItem.selection.cbegin(), historyItem.selection.cend(),
+                    [](const QPersistentModelIndex &i) { return !i.isValid(); })) {
+        historyItem.selection.clear();
+        return;
+    }
+
+    QAbstractItemView *view = q->viewMode() == QFileDialog::List
+        ? static_cast<QAbstractItemView *>(qFileDialogUi->listView)
+        : static_cast<QAbstractItemView *>(qFileDialogUi->treeView);
+    auto selectionModel = view->selectionModel();
+    const QItemSelectionModel::SelectionFlags flags = QItemSelectionModel::Select
+        | QItemSelectionModel::Rows;
+    selectionModel->select(historyItem.selection.constFirst(),
+                           flags | QItemSelectionModel::Clear | QItemSelectionModel::Current);
+    for (int i = 1, size = historyItem.selection.size(); i < size; ++i)
+        selectionModel->select(historyItem.selection.at(i), flags);
+
+    view->scrollTo(historyItem.selection.constFirst());
+}
+
 /*!
     \internal
 
@@ -3403,11 +3449,9 @@ void QFileDialogPrivate::_q_pathChanged(const QString &newPath)
 */
 void QFileDialogPrivate::_q_navigateBackward()
 {
-    Q_Q(QFileDialog);
     if (!currentHistory.isEmpty() && currentHistoryLocation > 0) {
-        --currentHistoryLocation;
-        QString previousHistory = currentHistory.at(currentHistoryLocation);
-        q->setDirectory(previousHistory);
+        saveHistorySelection();
+        navigate(currentHistory[--currentHistoryLocation]);
     }
 }
 
@@ -3418,11 +3462,9 @@ void QFileDialogPrivate::_q_navigateBackward()
 */
 void QFileDialogPrivate::_q_navigateForward()
 {
-    Q_Q(QFileDialog);
     if (!currentHistory.isEmpty() && currentHistoryLocation < currentHistory.size() - 1) {
-        ++currentHistoryLocation;
-        QString nextHistory = currentHistory.at(currentHistoryLocation);
-        q->setDirectory(nextHistory);
+        saveHistorySelection();
+        navigate(currentHistory[++currentHistoryLocation]);
     }
 }
 
@@ -3633,12 +3675,13 @@ void QFileDialogPrivate::_q_autoCompleteFileName(const QString &text)
             if (oldFiles.removeAll(idx) == 0)
                 newFiles.append(idx);
         }
-        for (int i = 0; i < newFiles.count(); ++i)
-            select(newFiles.at(i));
-        if (lineEdit()->hasFocus())
-            for (int i = 0; i < oldFiles.count(); ++i)
-                qFileDialogUi->listView->selectionModel()->select(oldFiles.at(i),
-                    QItemSelectionModel::Toggle | QItemSelectionModel::Rows);
+        for (const auto &newFile : qAsConst(newFiles))
+            select(newFile);
+        if (lineEdit()->hasFocus()) {
+            auto *sm = qFileDialogUi->listView->selectionModel();
+            for (const auto &oldFile : qAsConst(oldFiles))
+                sm->select(oldFile, QItemSelectionModel::Toggle | QItemSelectionModel::Rows);
+        }
     }
 }
 
diff --git a/src/widgets/dialogs/qfiledialog.h b/src/widgets/dialogs/qfiledialog.h
index 95e03618ac..354a1f928b 100644
--- a/src/widgets/dialogs/qfiledialog.h
+++ b/src/widgets/dialogs/qfiledialog.h
@@ -92,7 +92,9 @@ public:
         ShowDirsOnly                = 0x00000001,
         DontResolveSymlinks         = 0x00000002,
         DontConfirmOverwrite        = 0x00000004,
-        DontUseSheet                = 0x00000008,
+#if QT_DEPRECATED_SINCE(5, 14)
+        DontUseSheet Q_DECL_ENUMERATOR_DEPRECATED = 0x00000008,
+#endif
         DontUseNativeDialog         = 0x00000010,
         ReadOnly                    = 0x00000020,
         HideNameFilterDetails       = 0x00000040,
diff --git a/src/widgets/dialogs/qfiledialog_p.h b/src/widgets/dialogs/qfiledialog_p.h
index 463c77aa23..dcf147348f 100644
--- a/src/widgets/dialogs/qfiledialog_p.h
+++ b/src/widgets/dialogs/qfiledialog_p.h
@@ -98,7 +98,7 @@ class QPlatformDialogHelper;
 
 struct QFileDialogArgs
 {
-    QFileDialogArgs() : parent(0), mode(QFileDialog::AnyFile) {}
+    QFileDialogArgs() : parent(nullptr), mode(QFileDialog::AnyFile) {}
 
     QWidget *parent;
     QString caption;
@@ -116,6 +116,14 @@ class Q_WIDGETS_EXPORT QFileDialogPrivate : public QDialogPrivate
     Q_DECLARE_PUBLIC(QFileDialog)
 
 public:
+    using PersistentModelIndexList = QVector<QPersistentModelIndex>;
+
+    struct HistoryItem
+    {
+        QString path;
+        PersistentModelIndexList selection;
+    };
+
     QFileDialogPrivate();
 
     QPlatformFileDialogHelper *platformFileDialogHelper() const
@@ -193,9 +201,11 @@ public:
     void retranslateWindowTitle();
     void retranslateStrings();
     void emitFilesSelected(const QStringList &files);
+    void saveHistorySelection();
 
     void _q_goHome();
     void _q_pathChanged(const QString &);
+    void navigate(HistoryItem &);
     void _q_navigateBackward();
     void _q_navigateForward();
     void _q_navigateToParent();
@@ -237,7 +247,7 @@ public:
 
     QString setWindowTitle;
 
-    QStringList currentHistory;
+    QList<HistoryItem> currentHistory;
     int currentHistoryLocation;
 
     QAction *renameAction;
@@ -292,7 +302,7 @@ private:
 class QFileDialogLineEdit : public QLineEdit
 {
 public:
-    QFileDialogLineEdit(QWidget *parent = 0) : QLineEdit(parent), d_ptr(0){}
+    QFileDialogLineEdit(QWidget *parent = nullptr) : QLineEdit(parent), d_ptr(nullptr){}
     void setFileDialogPrivate(QFileDialogPrivate *d_pointer) {d_ptr = d_pointer; }
     void keyPressEvent(QKeyEvent *e) override;
     bool hideOnEsc;
@@ -303,7 +313,7 @@ private:
 class QFileDialogComboBox : public QComboBox
 {
 public:
-    QFileDialogComboBox(QWidget *parent = 0) : QComboBox(parent), urlModel(0) {}
+    QFileDialogComboBox(QWidget *parent = nullptr) : QComboBox(parent), urlModel(nullptr) {}
     void setFileDialogPrivate(QFileDialogPrivate *d_pointer);
     void showPopup() override;
     void setHistory(const QStringList &paths);
@@ -319,7 +329,7 @@ private:
 class QFileDialogListView : public QListView
 {
 public:
-    QFileDialogListView(QWidget *parent = 0);
+    QFileDialogListView(QWidget *parent = nullptr);
     void setFileDialogPrivate(QFileDialogPrivate *d_pointer);
     QSize sizeHint() const override;
 protected:
diff --git a/src/widgets/dialogs/qfileinfogatherer.cpp b/src/widgets/dialogs/qfileinfogatherer.cpp
index 1e03ad8b06..9ab75e0b0a 100644
--- a/src/widgets/dialogs/qfileinfogatherer.cpp
+++ b/src/widgets/dialogs/qfileinfogatherer.cpp
@@ -54,12 +54,12 @@ QT_BEGIN_NAMESPACE
 static QBasicAtomicInt fetchedRoot = Q_BASIC_ATOMIC_INITIALIZER(false);
 Q_AUTOTEST_EXPORT void qt_test_resetFetchedRoot()
 {
-    fetchedRoot.store(false);
+    fetchedRoot.storeRelaxed(false);
 }
 
 Q_AUTOTEST_EXPORT bool qt_test_isFetchedRoot()
 {
-    return fetchedRoot.load();
+    return fetchedRoot.loadRelaxed();
 }
 #endif
 
@@ -79,14 +79,8 @@ static QString translateDriveName(const QFileInfo &drive)
     Creates thread
 */
 QFileInfoGatherer::QFileInfoGatherer(QObject *parent)
-    : QThread(parent), abort(false),
-#if QT_CONFIG(filesystemwatcher)
-      watcher(0),
-#endif
-#ifdef Q_OS_WIN
-      m_resolveSymlinks(true),
-#endif
-      m_iconProvider(&defaultProvider)
+    : QThread(parent)
+    , m_iconProvider(&defaultProvider)
 {
 #if QT_CONFIG(filesystemwatcher)
     watcher = new QFileSystemWatcher(this);
@@ -111,7 +105,7 @@ QFileInfoGatherer::QFileInfoGatherer(QObject *parent)
 */
 QFileInfoGatherer::~QFileInfoGatherer()
 {
-    abort.store(true);
+    abort.storeRelaxed(true);
     QMutexLocker locker(&mutex);
     condition.wakeAll();
     locker.unlock();
@@ -247,9 +241,9 @@ void QFileInfoGatherer::run()
 {
     forever {
         QMutexLocker locker(&mutex);
-        while (!abort.load() && path.isEmpty())
+        while (!abort.loadRelaxed() && path.isEmpty())
             condition.wait(&mutex);
-        if (abort.load())
+        if (abort.loadRelaxed())
             return;
         const QString thisPath = qAsConst(path).front();
         path.pop_front();
@@ -303,7 +297,7 @@ void QFileInfoGatherer::getFileInfos(const QString &path, const QStringList &fil
     // List drives
     if (path.isEmpty()) {
 #ifdef QT_BUILD_INTERNAL
-        fetchedRoot.store(true);
+        fetchedRoot.storeRelaxed(true);
 #endif
         QFileInfoList infoList;
         if (files.isEmpty()) {
@@ -332,7 +326,7 @@ void QFileInfoGatherer::getFileInfos(const QString &path, const QStringList &fil
     QStringList allFiles;
     if (files.isEmpty()) {
         QDirIterator dirIt(path, QDir::AllEntries | QDir::System | QDir::Hidden);
-        while (!abort.load() && dirIt.hasNext()) {
+        while (!abort.loadRelaxed() && dirIt.hasNext()) {
             dirIt.next();
             fileInfo = dirIt.fileInfo();
             allFiles.append(fileInfo.fileName());
@@ -343,7 +337,7 @@ void QFileInfoGatherer::getFileInfos(const QString &path, const QStringList &fil
         emit newListOfFiles(path, allFiles);
 
     QStringList::const_iterator filesIt = filesToCheck.constBegin();
-    while (!abort.load() && filesIt != filesToCheck.constEnd()) {
+    while (!abort.loadRelaxed() && filesIt != filesToCheck.constEnd()) {
         fileInfo.setFile(path + QDir::separator() + *filesIt);
         ++filesIt;
         fetch(fileInfo, base, firstTime, updatedFiles, path);
diff --git a/src/widgets/dialogs/qfileinfogatherer_p.h b/src/widgets/dialogs/qfileinfogatherer_p.h
index 134a14b7ce..829c620c1e 100644
--- a/src/widgets/dialogs/qfileinfogatherer_p.h
+++ b/src/widgets/dialogs/qfileinfogatherer_p.h
@@ -166,7 +166,7 @@ Q_SIGNALS:
     void directoryLoaded(const QString &path);
 
 public:
-    explicit QFileInfoGatherer(QObject *parent = 0);
+    explicit QFileInfoGatherer(QObject *parent = nullptr);
     ~QFileInfoGatherer();
 
 #if QT_CONFIG(filesystemwatcher) && defined(Q_OS_WIN)
@@ -210,13 +210,13 @@ private:
     QAtomicInt abort;
 
 #if QT_CONFIG(filesystemwatcher)
-    QFileSystemWatcher *watcher;
-#endif
-#ifdef Q_OS_WIN
-    bool m_resolveSymlinks; // not accessed by run()
+    QFileSystemWatcher *watcher = nullptr;
 #endif
     QFileIconProvider *m_iconProvider; // not accessed by run()
     QFileIconProvider defaultProvider;
+#ifdef Q_OS_WIN
+    bool m_resolveSymlinks = true; // not accessed by run()
+#endif
 };
 
 QT_END_NAMESPACE
diff --git a/src/widgets/dialogs/qfilesystemmodel.cpp b/src/widgets/dialogs/qfilesystemmodel.cpp
index e486037e08..820fc6e220 100644
--- a/src/widgets/dialogs/qfilesystemmodel.cpp
+++ b/src/widgets/dialogs/qfilesystemmodel.cpp
@@ -227,11 +227,9 @@ bool QFileSystemModel::remove(const QModelIndex &aindex)
 /*!
   Constructs a file system model with the given \a parent.
 */
-QFileSystemModel::QFileSystemModel(QObject *parent)
-    : QAbstractItemModel(*new QFileSystemModelPrivate, parent)
+QFileSystemModel::QFileSystemModel(QObject *parent) :
+    QFileSystemModel(*new QFileSystemModelPrivate, parent)
 {
-    Q_D(QFileSystemModel);
-    d->init();
 }
 
 /*!
@@ -247,9 +245,7 @@ QFileSystemModel::QFileSystemModel(QFileSystemModelPrivate &dd, QObject *parent)
 /*!
   Destroys this file system model.
 */
-QFileSystemModel::~QFileSystemModel()
-{
-}
+QFileSystemModel::~QFileSystemModel() = default;
 
 /*!
     \reimp
@@ -1390,7 +1386,7 @@ QModelIndex QFileSystemModel::setRootPath(const QString &newPath)
     if (d->rootDir.path() == longNewPath)
         return d->index(rootPath());
 
-    bool showDrives = (longNewPath.isEmpty() || longNewPath == d->myComputer());
+    bool showDrives = (longNewPath.isEmpty() || longNewPath == QFileSystemModelPrivate::myComputer());
     if (!showDrives && !newPathDir.exists())
         return d->index(rootPath());
 
@@ -1847,8 +1843,7 @@ void QFileSystemModelPrivate::_q_fileSystemChanged(const QString &path, const QV
     std::sort(rowsToUpdate.begin(), rowsToUpdate.end());
     QString min;
     QString max;
-    for (int i = 0; i < rowsToUpdate.count(); ++i) {
-        QString value = rowsToUpdate.at(i);
+    for (const QString &value : qAsConst(rowsToUpdate)) {
         //##TODO is there a way to bundle signals with QString as the content of the list?
         /*if (min.isEmpty()) {
             min = value;
@@ -1946,6 +1941,9 @@ QStringList QFileSystemModelPrivate::unwatchPathsAt(const QModelIndex &index)
 void QFileSystemModelPrivate::init()
 {
     Q_Q(QFileSystemModel);
+
+    delayedSortTimer.setSingleShot(true);
+
     qRegisterMetaType<QVector<QPair<QString,QFileInfo> > >();
 #if QT_CONFIG(filesystemwatcher)
     q->connect(&fileInfoGatherer, SIGNAL(newListOfFiles(QString,QStringList)),
diff --git a/src/widgets/dialogs/qfilesystemmodel_p.h b/src/widgets/dialogs/qfilesystemmodel_p.h
index 9c432e1ae6..844e417e2d 100644
--- a/src/widgets/dialogs/qfilesystemmodel_p.h
+++ b/src/widgets/dialogs/qfilesystemmodel_p.h
@@ -99,13 +99,13 @@ public:
     class QFileSystemNode
     {
     public:
-        explicit QFileSystemNode(const QString &filename = QString(), QFileSystemNode *p = 0)
-            : fileName(filename), populatedChildren(false), isVisible(false), dirtyChildrenIndex(-1), parent(p), info(0) {}
+        Q_DISABLE_COPY_MOVE(QFileSystemNode)
+
+        explicit QFileSystemNode(const QString &filename = QString(), QFileSystemNode *p = nullptr)
+            : fileName(filename), parent(p) {}
         ~QFileSystemNode() {
             qDeleteAll(children);
             delete info;
-            info = 0;
-            parent = 0;
         }
 
         QString fileName;
@@ -116,7 +116,7 @@ public:
         inline qint64 size() const { if (info && !info->isDir()) return info->size(); return 0; }
         inline QString type() const { if (info) return info->displayType; return QLatin1String(""); }
         inline QDateTime lastModified() const { if (info) return info->lastModified(); return QDateTime(); }
-        inline QFile::Permissions permissions() const { if (info) return info->permissions(); return 0; }
+        inline QFile::Permissions permissions() const { if (info) return info->permissions(); return nullptr; }
         inline bool isReadable() const { return ((permissions() & QFile::ReadUser) != 0); }
         inline bool isWritable() const { return ((permissions() & QFile::WriteUser) != 0); }
         inline bool isExecutable() const { return ((permissions() & QFile::ExeUser) != 0); }
@@ -162,7 +162,7 @@ public:
             return info && (*info == fileInfo);
         }
 
-        inline bool hasInformation() const { return info != 0; }
+        inline bool hasInformation() const { return info != nullptr; }
 
         void populate(const QExtendedInformation &fileInfo) {
             if (!info)
@@ -204,31 +204,16 @@ public:
             }
         }
 
-        bool populatedChildren;
-        bool isVisible;
         QHash<QFileSystemModelNodePathKey, QFileSystemNode *> children;
         QList<QString> visibleChildren;
-        int dirtyChildrenIndex;
+        QExtendedInformation *info = nullptr;
         QFileSystemNode *parent;
-
-
-        QExtendedInformation *info;
-
+        int dirtyChildrenIndex = -1;
+        bool populatedChildren = false;
+        bool isVisible = false;
     };
 
-    QFileSystemModelPrivate() :
-            forceSort(true),
-            sortColumn(0),
-            sortOrder(Qt::AscendingOrder),
-            readOnly(true),
-            setRootPath(false),
-            filters(QDir::AllEntries | QDir::NoDotAndDotDot | QDir::AllDirs),
-            nameFilterDisables(true), // false on windows, true on mac and unix
-            disableRecursiveSort(false)
-    {
-        delayedSortTimer.setSingleShot(true);
-    }
-
+    QFileSystemModelPrivate() = default;
     void init();
     /*
       \internal
@@ -303,18 +288,7 @@ public:
     QFileInfoGatherer fileInfoGatherer;
 #endif // filesystemwatcher
     QTimer delayedSortTimer;
-    bool forceSort;
-    int sortColumn;
-    Qt::SortOrder sortOrder;
-    bool readOnly;
-    bool setRootPath;
-    QDir::Filters filters;
     QHash<const QFileSystemNode*, bool> bypassFilters;
-    bool nameFilterDisables;
-    //This flag is an optimization for the QFileDialog
-    //It enable a sort which is not recursive, it means
-    //we sort only what we see.
-    bool disableRecursiveSort;
 #if QT_CONFIG(regularexpression)
     QStringList nameFilters;
 #endif
@@ -322,7 +296,6 @@ public:
 
     QFileSystemNode root;
 
-    QBasicTimer fetchingTimer;
     struct Fetching {
         QString dir;
         QString file;
@@ -330,6 +303,18 @@ public:
     };
     QVector<Fetching> toFetch;
 
+    QBasicTimer fetchingTimer;
+
+    QDir::Filters filters = QDir::AllEntries | QDir::NoDotAndDotDot | QDir::AllDirs;
+    int sortColumn = 0;
+    Qt::SortOrder sortOrder = Qt::AscendingOrder;
+    bool forceSort = true;
+    bool readOnly = true;
+    bool setRootPath = false;
+    bool nameFilterDisables = true; // false on windows, true on mac and unix
+    // This flag is an optimization for QFileDialog. It enables a sort which is
+    // not recursive, meaning we sort only what we see.
+    bool disableRecursiveSort = false;
 };
 Q_DECLARE_TYPEINFO(QFileSystemModelPrivate::Fetching, Q_MOVABLE_TYPE);
 
diff --git a/src/widgets/dialogs/qfontdialog.cpp b/src/widgets/dialogs/qfontdialog.cpp
index d53d57db86..7e3592e034 100644
--- a/src/widgets/dialogs/qfontdialog.cpp
+++ b/src/widgets/dialogs/qfontdialog.cpp
@@ -432,7 +432,7 @@ bool QFontDialog::eventFilter(QObject *o , QEvent *e)
          k->key() == Qt::Key_PageDown)) {
 
             int ci = d->sizeList->currentItem();
-            (void)QApplication::sendEvent(d->sizeList, k);
+            QCoreApplication::sendEvent(d->sizeList, k);
 
             if (ci != d->sizeList->currentItem()
                     && style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, this))
@@ -680,7 +680,7 @@ void QFontDialogPrivate::updateSampleFont(const QFont &newFont)
 void QFontDialogPrivate::_q_writingSystemHighlighted(int index)
 {
     writingSystem = QFontDatabase::WritingSystem(index);
-    sampleEdit->setText(fdb.writingSystemSample(writingSystem));
+    sampleEdit->setText(QFontDatabase::writingSystemSample(writingSystem));
     updateFamilies();
 }
 
diff --git a/src/widgets/dialogs/qfscompleter_p.h b/src/widgets/dialogs/qfscompleter_p.h
index 3b829d4a52..f5110a7622 100644
--- a/src/widgets/dialogs/qfscompleter_p.h
+++ b/src/widgets/dialogs/qfscompleter_p.h
@@ -64,8 +64,8 @@ QT_BEGIN_NAMESPACE
   */
 class Q_WIDGETS_EXPORT QFSCompleter :  public QCompleter {
 public:
-    explicit QFSCompleter(QFileSystemModel *model, QObject *parent = 0)
-        : QCompleter(model, parent), proxyModel(0), sourceModel(model)
+    explicit QFSCompleter(QFileSystemModel *model, QObject *parent = nullptr)
+        : QCompleter(model, parent), proxyModel(nullptr), sourceModel(model)
     {
 #if defined(Q_OS_WIN)
         setCaseSensitivity(Qt::CaseInsensitive);
diff --git a/src/widgets/dialogs/qmessagebox.cpp b/src/widgets/dialogs/qmessagebox.cpp
index f143e3b527..8dad212692 100644
--- a/src/widgets/dialogs/qmessagebox.cpp
+++ b/src/widgets/dialogs/qmessagebox.cpp
@@ -1508,7 +1508,7 @@ void QMessageBox::keyPressEvent(QKeyEvent *e)
             if (d->detailsText)
                 textToCopy += d->detailsText->text() + QLatin1Char('\n') + separator;
 #endif
-            QApplication::clipboard()->setText(textToCopy);
+            QGuiApplication::clipboard()->setText(textToCopy);
             return;
         }
 #endif // Q_OS_WIN
@@ -2662,14 +2662,9 @@ QPixmap QMessageBoxPrivate::standardIcon(QMessageBox::Icon icon, QMessageBox *mb
         break;
     }
     if (!tmpIcon.isNull()) {
-        QWindow *window = nullptr;
-        if (mb) {
-            window = mb->windowHandle();
-            if (!window) {
-                if (const QWidget *nativeParent = mb->nativeParentWidget())
-                    window = nativeParent->windowHandle();
-            }
-        }
+        QWindow *window = mb
+            ? qt_widget_private(mb)->windowHandle(QWidgetPrivate::WindowHandleMode::Closest)
+            : nullptr;
         return tmpIcon.pixmap(window, QSize(iconSize, iconSize));
     }
     return QPixmap();
diff --git a/src/widgets/dialogs/qprogressdialog.cpp b/src/widgets/dialogs/qprogressdialog.cpp
index 078dd6463b..e1a6bce5b1 100644
--- a/src/widgets/dialogs/qprogressdialog.cpp
+++ b/src/widgets/dialogs/qprogressdialog.cpp
@@ -643,7 +643,7 @@ int QProgressDialog::value() const
 
   \warning If the progress dialog is modal
     (see QProgressDialog::QProgressDialog()),
-    setValue() calls QApplication::processEvents(), so take care that
+    setValue() calls QCoreApplication::processEvents(), so take care that
     this does not cause undesirable re-entrancy in your code. For example,
     don't use a QProgressDialog inside a paintEvent()!
 
@@ -659,7 +659,7 @@ void QProgressDialog::setValue(int progress)
 
     if (d->shown_once) {
         if (isModal())
-            QApplication::processEvents();
+            QCoreApplication::processEvents();
     } else {
         if ((!d->setValue_called && progress == 0 /* for compat with Qt < 5.4 */) || progress == minimum()) {
             d->starttime.start();
diff --git a/src/widgets/dialogs/qsidebar_p.h b/src/widgets/dialogs/qsidebar_p.h
index 4a82f88878..6056f19452 100644
--- a/src/widgets/dialogs/qsidebar_p.h
+++ b/src/widgets/dialogs/qsidebar_p.h
@@ -67,7 +67,7 @@ class QFileSystemModel;
 class QSideBarDelegate : public QStyledItemDelegate
 {
  public:
-     QSideBarDelegate(QWidget *parent = 0) : QStyledItemDelegate(parent) {}
+     QSideBarDelegate(QWidget *parent = nullptr) : QStyledItemDelegate(parent) {}
      void initStyleOption(QStyleOptionViewItem *option,
                           const QModelIndex &index) const override;
 };
@@ -82,7 +82,7 @@ public:
         EnabledRole = Qt::UserRole + 2
     };
 
-    QUrlModel(QObject *parent = 0);
+    QUrlModel(QObject *parent = nullptr);
 
     QStringList mimeTypes() const override;
     QMimeData *mimeData(const QModelIndexList &indexes) const override;
@@ -127,7 +127,7 @@ Q_SIGNALS:
     void goToUrl(const QUrl &url);
 
 public:
-    QSidebar(QWidget *parent = 0);
+    QSidebar(QWidget *parent = nullptr);
     void setModelAndUrls(QFileSystemModel *model, const QList<QUrl> &newUrls);
     ~QSidebar();
 
diff --git a/src/widgets/dialogs/qwizard.cpp b/src/widgets/dialogs/qwizard.cpp
index 88b187cd7f..4d28dda7c7 100644
--- a/src/widgets/dialogs/qwizard.cpp
+++ b/src/widgets/dialogs/qwizard.cpp
@@ -1595,23 +1595,25 @@ bool QWizardPrivate::handleAeroStyleChange()
     bool vistaMargins = false;
 
     if (isVistaThemeEnabled()) {
+        const int topOffset = vistaHelper->topOffset();
+        const int topPadding = vistaHelper->topPadding();
         if (isVistaThemeEnabled(QVistaHelper::VistaAero)) {
             if (isWindow) {
                 vistaHelper->setDWMTitleBar(QVistaHelper::ExtendedTitleBar);
                 q->installEventFilter(vistaHelper);
             }
             q->setMouseTracking(true);
-            antiFlickerWidget->move(0, vistaHelper->titleBarSize() + vistaHelper->topOffset());
+            antiFlickerWidget->move(0, vistaHelper->titleBarSize() + topOffset);
             vistaHelper->backButton()->move(
-                0, vistaHelper->topOffset() // ### should ideally work without the '+ 1'
-                - qMin(vistaHelper->topOffset(), vistaHelper->topPadding() + 1));
+                0, topOffset // ### should ideally work without the '+ 1'
+                - qMin(topOffset, topPadding + 1));
             vistaMargins = true;
             vistaHelper->backButton()->show();
         } else {
             if (isWindow)
                 vistaHelper->setDWMTitleBar(QVistaHelper::NormalTitleBar);
             q->setMouseTracking(true);
-            antiFlickerWidget->move(0, vistaHelper->topOffset());
+            antiFlickerWidget->move(0, topOffset);
             vistaHelper->backButton()->move(0, -1); // ### should ideally work with (0, 0)
         }
         if (isWindow)
@@ -2575,7 +2577,7 @@ void QWizard::setWizardStyle(WizardStyle style)
             //Send a resizeevent since the antiflicker widget probably needs a new size
             //because of the backbutton in the window title
             QResizeEvent ev(geometry().size(), geometry().size());
-            QApplication::sendEvent(this, &ev);
+            QCoreApplication::sendEvent(this, &ev);
         }
 #endif
         d->updateLayout();
@@ -3257,7 +3259,11 @@ void QWizard::paintEvent(QPaintEvent * event)
 /*!
     \reimp
 */
+#  if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+bool QWizard::nativeEvent(const QByteArray &eventType, void *message, qintptr *result)
+#  else
 bool QWizard::nativeEvent(const QByteArray &eventType, void *message, long *result)
+#  endif
 {
 #if QT_CONFIG(style_windowsvista)
     Q_D(QWizard);
diff --git a/src/widgets/dialogs/qwizard.h b/src/widgets/dialogs/qwizard.h
index 0dd837b197..ef71efa0cb 100644
--- a/src/widgets/dialogs/qwizard.h
+++ b/src/widgets/dialogs/qwizard.h
@@ -188,7 +188,11 @@ protected:
     void resizeEvent(QResizeEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
 #if defined(Q_OS_WIN) || defined(Q_CLANG_QDOC)
+#  if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    bool nativeEvent(const QByteArray &eventType, void *message, qintptr *result) override;
+#  else
     bool nativeEvent(const QByteArray &eventType, void *message, long *result) override;
+#  endif
 #endif
     void done(int result) override;
     virtual void initializePage(int id);
diff --git a/src/widgets/dialogs/qwizard_win.cpp b/src/widgets/dialogs/qwizard_win.cpp
index aa9ad7f290..95f8f6a878 100644
--- a/src/widgets/dialogs/qwizard_win.cpp
+++ b/src/widgets/dialogs/qwizard_win.cpp
@@ -172,7 +172,7 @@ void QVistaHelper::updateCustomMargins(bool vistaMargins)
         const QMargins customMarginsDp = vistaMargins
             ? QMargins(0, -titleBarSizeDp(), 0, 0)
             : QMargins();
-        const QVariant customMarginsV = qVariantFromValue(customMarginsDp);
+        const QVariant customMarginsV = QVariant::fromValue(customMarginsDp);
         // The dynamic property takes effect when creating the platform window.
         window->setProperty("_q_windowsCustomMargins", customMarginsV);
         // If a platform window exists, change via native interface.
@@ -293,9 +293,9 @@ void QVistaHelper::drawTitleBar(QPainter *painter)
     int glowOffset = 0;
 
     if (vistaState() == VistaAero) {
-        textHeight += 2 * glowSize();
-        textWidth += 2 * glowSize();
         glowOffset = glowSize();
+        textHeight += 2 * glowOffset;
+        textWidth += 2 * glowOffset;
     }
 
     const int titleLeft = (wizard->layoutDirection() == Qt::LeftToRight
@@ -339,7 +339,11 @@ void QVistaHelper::setTitleBarIconAndCaptionVisible(bool visible)
         SetWindowThemeAttribute(handle, WTA_NONCLIENT, &opt, sizeof(WTA_OPTIONS));
 }
 
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+bool QVistaHelper::winEvent(MSG* msg, qintptr *result)
+#else
 bool QVistaHelper::winEvent(MSG* msg, long* result)
+#endif
 {
     switch (msg->message) {
     case WM_NCHITTEST: {
@@ -401,7 +405,11 @@ void QVistaHelper::mouseEvent(QEvent *event)
     }
 }
 
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+bool QVistaHelper::handleWinEvent(MSG *message, qintptr *result)
+#else
 bool QVistaHelper::handleWinEvent(MSG *message, long *result)
+#endif
 {
     if (message->message == WM_THEMECHANGED || message->message == WM_DWMCOMPOSITIONCHANGED)
         cachedVistaState = Dirty;
@@ -509,7 +517,11 @@ bool QVistaHelper::eventFilter(QObject *obj, QEvent *event)
 
     if (event->type() == QEvent::MouseMove) {
         QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+        qintptr result;
+#else
         long result;
+#endif
         MSG msg;
         msg.message = WM_NCHITTEST;
         msg.wParam  = 0;
@@ -523,7 +535,11 @@ bool QVistaHelper::eventFilter(QObject *obj, QEvent *event)
         QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
 
         if (mouseEvent->button() == Qt::LeftButton) {
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+            qintptr result;
+#else
             long result;
+#endif
             MSG msg;
             msg.message = WM_NCHITTEST;
             msg.wParam  = 0;
@@ -538,7 +554,11 @@ bool QVistaHelper::eventFilter(QObject *obj, QEvent *event)
         QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
 
         if (mouseEvent->button() == Qt::LeftButton) {
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+            qintptr result;
+#else
             long result;
+#endif
             MSG msg;
             msg.message = WM_NCHITTEST;
             msg.wParam  = 0;
diff --git a/src/widgets/dialogs/qwizard_win_p.h b/src/widgets/dialogs/qwizard_win_p.h
index 02c5e52c2c..b3796e3f48 100644
--- a/src/widgets/dialogs/qwizard_win_p.h
+++ b/src/widgets/dialogs/qwizard_win_p.h
@@ -93,7 +93,11 @@ public:
     bool setDWMTitleBar(TitleBarChangeType type);
     void setTitleBarIconAndCaptionVisible(bool visible);
     void mouseEvent(QEvent *event);
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    bool handleWinEvent(MSG *message, qintptr *result);
+#else
     bool handleWinEvent(MSG *message, long *result);
+#endif
     void resizeEvent(QResizeEvent *event);
     void paintEvent(QPaintEvent *event);
     QVistaBackButton *backButton() const { return backButton_; }
@@ -130,7 +134,11 @@ private:
     void drawTitleBar(QPainter *painter);
     void setMouseCursor(QPoint pos);
     void collapseTopFrameStrut();
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    bool winEvent(MSG *message, qintptr *result);
+#else
     bool winEvent(MSG *message, long *result);
+#endif
     void mouseMoveEvent(QMouseEvent *event);
     void mousePressEvent(QMouseEvent *event);
     void mouseReleaseEvent(QMouseEvent *event);