Merge tag 'v6.5.6-lts-lgpl' into 6.56.5

Qt 6.5.6-lts-lgpl release

43 files changed, 262 insertions, 120 deletions

diff --git a/src/corelib/CMakeLists.txt b/src/corelib/CMakeLists.txt
index 4630a3a587f..4784a310f79 100644
--- a/src/corelib/CMakeLists.txt
+++ b/src/corelib/CMakeLists.txt
@@ -316,7 +316,6 @@ qt_internal_add_module(Core
         text/qstringconverter.cpp # enum Data
         tools/qcryptographichash.cpp # KeccakNISTInterface/Final
         io/qdebug.cpp # undef qDebug
-        io/qsettings.cpp # Space (also in qjsonparser.cpp)
     NO_PCH_SOURCES
         compat/removed_api.cpp
         global/qsimd.cpp
@@ -1409,4 +1408,10 @@ foreach(minor_version RANGE ${PROJECT_VERSION_MINOR})
 endforeach()
 qt_internal_extend_target(Core
     EXTRA_LINKER_SCRIPT_CONTENT "${linker_script_contents}"
+
+    # Workaround for QTBUG-117514:
+    # Function called by inline methods taking a pointer to a private class as a parameter
+    EXTRA_LINKER_SCRIPT_EXPORTS
+        # QFutureInterfaceBase::setContinuation(std::function<void (QFutureInterfaceBase const&)>, QFutureInterfaceBasePrivate*)
+        "_ZN20QFutureInterfaceBase15setContinuationE*P27QFutureInterfaceBasePrivate"
 )
diff --git a/src/corelib/Qt6AndroidMacros.cmake b/src/corelib/Qt6AndroidMacros.cmake
index 9a8d02165f2..66f508f3b23 100644
--- a/src/corelib/Qt6AndroidMacros.cmake
+++ b/src/corelib/Qt6AndroidMacros.cmake
@@ -236,6 +236,10 @@ function(qt6_android_generate_deployment_settings target)
     _qt_internal_add_android_deployment_property(file_contents "android-no-deploy-qt-libs"
         ${target} "QT_ANDROID_NO_DEPLOY_QT_LIBS")
 
+    __qt_internal_collect_plugin_targets_from_dependencies("${target}" plugin_targets)
+    __qt_internal_collect_plugin_library_files("${target}" "${plugin_targets}" plugin_targets)
+    string(APPEND file_contents "   \"android-deploy-plugins\":\"${plugin_targets}\",\n")
+
     # App binary
     string(APPEND file_contents
         "   \"application-binary\": \"${target_output_name}\",\n")
@@ -303,7 +307,7 @@ function(qt6_android_generate_deployment_settings target)
     # content end
     string(APPEND file_contents "}\n")
 
-    file(GENERATE OUTPUT ${deploy_file} CONTENT ${file_contents})
+    file(GENERATE OUTPUT ${deploy_file} CONTENT "${file_contents}")
 
     set_target_properties(${target}
         PROPERTIES
@@ -554,7 +558,7 @@ function(qt6_android_add_apk_target target)
             "$<TARGET_FILE:${target}>"
             "${androiddeployqt_output_path}/${target_file_copy_relative_path}"
         )
-        if(has_depfile_support)
+        if(has_depfile_support AND FALSE) # TODO: It breaks multi-abi builds. See QTBUG-122838
             set(deploy_android_deps_dir "${apk_final_dir}/${target}_deploy_android")
             set(timestamp_file "${deploy_android_deps_dir}/timestamp")
             set(dep_file "${deploy_android_deps_dir}/${target}.d")
@@ -1007,7 +1011,8 @@ function(_qt_internal_get_android_abi_cmake_dir_path out_path abi)
             NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_INTERNAL_IS_STANDALONE_TEST)
             set(cmake_dir "${QT_CONFIG_BUILD_DIR}")
         else()
-            set(cmake_dir "${prefix_path}/${QT6_INSTALL_LIBS}/cmake")
+            string(TOUPPER "${QT_CMAKE_EXPORT_NAMESPACE}" export_namespace_upper)
+            set(cmake_dir "${prefix_path}/${${export_namespace_upper}_INSTALL_LIBS}/cmake")
         endif()
     endif()
 
diff --git a/src/corelib/Qt6CoreDeploySupport.cmake b/src/corelib/Qt6CoreDeploySupport.cmake
index 999708185ec..b3cfe29160f 100644
--- a/src/corelib/Qt6CoreDeploySupport.cmake
+++ b/src/corelib/Qt6CoreDeploySupport.cmake
@@ -437,8 +437,13 @@ function(qt6_deploy_runtime_dependencies)
 
         # Specify path to target Qt's qtpaths .exe or .bat file, so windeployqt deploys the correct
         # libraries when cross-compiling from x86_64 to arm64 windows.
-        if(__QT_DEPLOY_TARGET_QT_PATHS_PATH)
+        if(__QT_DEPLOY_TARGET_QT_PATHS_PATH AND EXISTS "${__QT_DEPLOY_TARGET_QT_PATHS_PATH}")
             list(APPEND tool_options --qtpaths "${__QT_DEPLOY_TARGET_QT_PATHS_PATH}")
+        else()
+            message(WARNING
+                "No qtpaths executable found for target Qt "
+                "at: ${__QT_DEPLOY_TARGET_QT_PATHS_PATH}. "
+                "Libraries may not be deployed correctly.")
         endif()
 
     elseif(__QT_DEPLOY_SYSTEM_NAME STREQUAL Darwin)
diff --git a/src/corelib/Qt6CoreMacros.cmake b/src/corelib/Qt6CoreMacros.cmake
index c692839b36f..f7f658d5afe 100644
--- a/src/corelib/Qt6CoreMacros.cmake
+++ b/src/corelib/Qt6CoreMacros.cmake
@@ -2666,7 +2666,30 @@ function(_qt_internal_setup_deploy_support)
     else()
         set(qt_paths_ext "")
     endif()
-    set(target_qtpaths_path "${QT6_INSTALL_PREFIX}/${QT6_INSTALL_BINS}/qtpaths${qt_paths_ext}")
+
+
+
+    set(target_qtpaths_path "")
+    set(qtpaths_prefix "${QT6_INSTALL_PREFIX}/${QT6_INSTALL_BINS}")
+    get_property(qt_major_version TARGET "${target}" PROPERTY INTERFACE_QT_MAJOR_VERSION)
+    if(qt_major_version)
+        set(target_qtpaths_with_major_version_path
+            "${qtpaths_prefix}/qtpaths${qt_major_version}${qt_paths_ext}")
+        if(EXISTS "${target_qtpaths_with_major_version_path}")
+            set(target_qtpaths_path "${target_qtpaths_with_major_version_path}")
+        endif()
+    endif()
+
+    if(NOT target_qtpaths_path)
+        set(target_qtpaths_path_without_version "${qtpaths_prefix}/qtpaths${qt_paths_ext}")
+        if(EXISTS "${target_qtpaths_path_without_version}")
+            set(target_qtpaths_path "${target_qtpaths_path_without_version}")
+        endif()
+    endif()
+
+    if(NOT target_qtpaths_path)
+        message(DEBUG "No qtpaths executable found for deployment purposes.")
+    endif()
 
     file(GENERATE OUTPUT "${QT_DEPLOY_SUPPORT}" CONTENT
 "cmake_minimum_required(VERSION 3.16...3.21)
diff --git a/src/corelib/compat/removed_api.cpp b/src/corelib/compat/removed_api.cpp
index 7acbae8a5e8..586d84d9497 100644
--- a/src/corelib/compat/removed_api.cpp
+++ b/src/corelib/compat/removed_api.cpp
@@ -200,7 +200,7 @@ void QObject::setObjectName(const QString &name)
 
 void QSettings::beginGroup(const QString &prefix)
 {
-    return beginGroup(qToAnyStringViewIgnoringNull(prefix));
+    beginGroup(qToAnyStringViewIgnoringNull(prefix));
 }
 
 int QSettings::beginReadArray(const QString &prefix)
diff --git a/src/corelib/debug_script.py b/src/corelib/debug_script.py
index 6dee5961524..f6207c6104e 100644
--- a/src/corelib/debug_script.py
+++ b/src/corelib/debug_script.py
@@ -1,5 +1,5 @@
 # Copyright (C) 2017 The Qt Company Ltd.
-# SPDX-License-Identifier: LicenseRef-Qt-Commercial
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
 import os
 import sys
diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index 58a36893412..02b5e64a69a 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -1370,6 +1370,11 @@ QT_WARNING_DISABLE_MSVC(4530) /* C++ exception handler used, but unwind semantic
 #  endif
 #endif
 
+// libstdc++ shipped with gcc < 11 does not have a fix for defect LWG 3346
+#if __cplusplus >= 202002L && (!defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE >= 11)
+#  define QT_COMPILER_HAS_LWG3346
+#endif
+
 #endif // __cplusplus
 
 #endif // QCOMPILERDETECTION_H
diff --git a/src/corelib/global/qglobalstatic.h b/src/corelib/global/qglobalstatic.h
index 26e22caced9..20701e0e54c 100644
--- a/src/corelib/global/qglobalstatic.h
+++ b/src/corelib/global/qglobalstatic.h
@@ -41,8 +41,16 @@ template <typename QGS> union Holder
 
     ~Holder()
     {
+        // TSAN does not support atomic_thread_fence and GCC complains:
+        // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97868
+        // https://github.com/google/sanitizers/issues/1352
+QT_WARNING_PUSH
+#if defined(Q_CC_GNU_ONLY) && Q_CC_GNU >= 1100
+QT_WARNING_DISABLE_GCC("-Wtsan")
+#endif
         // import changes to *pointer() by other threads before running ~PlainType():
         std::atomic_thread_fence(std::memory_order_acquire);
+QT_WARNING_POP
         pointer()->~PlainType();
         guard.storeRelease(QtGlobalStatic::Destroyed);
     }
diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
index ea281931c12..82857718911 100644
--- a/src/corelib/global/qlibraryinfo.cpp
+++ b/src/corelib/global/qlibraryinfo.cpp
@@ -87,10 +87,19 @@ void QLibrarySettings::load()
     }
 }
 
+namespace {
+const QString *qtconfManualPath = nullptr;
+}
+
+void QLibraryInfoPrivate::setQtconfManualPath(const QString *path)
+{
+    qtconfManualPath = path;
+}
+
 static QSettings *findConfiguration()
 {
-    if (QLibraryInfoPrivate::qtconfManualPath)
-        return new QSettings(*QLibraryInfoPrivate::qtconfManualPath, QSettings::IniFormat);
+    if (qtconfManualPath)
+        return new QSettings(*qtconfManualPath, QSettings::IniFormat);
 
     QString qtconfig = QStringLiteral(":/qt/etc/qt.conf");
     if (QFile::exists(qtconfig))
@@ -122,8 +131,6 @@ static QSettings *findConfiguration()
     return nullptr;     //no luck
 }
 
-const QString *QLibraryInfoPrivate::qtconfManualPath = nullptr;
-
 QSettings *QLibraryInfoPrivate::configuration()
 {
     QLibrarySettings *ls = qt_library_settings();
diff --git a/src/corelib/global/qlibraryinfo_p.h b/src/corelib/global/qlibraryinfo_p.h
index d3c458290b1..4b471b932e5 100644
--- a/src/corelib/global/qlibraryinfo_p.h
+++ b/src/corelib/global/qlibraryinfo_p.h
@@ -32,7 +32,7 @@ public:
 #if QT_CONFIG(settings)
     static QSettings *configuration();
     static void reload();
-    static const QString *qtconfManualPath;
+    static void setQtconfManualPath(const QString *qtconfManualPath);
 #endif
 
     struct LocationInfo
diff --git a/src/corelib/global/qtypeinfo.h b/src/corelib/global/qtypeinfo.h
index f493dce1ea4..95aa9f5dcdd 100644
--- a/src/corelib/global/qtypeinfo.h
+++ b/src/corelib/global/qtypeinfo.h
@@ -7,6 +7,7 @@
 #include <variant>
 #include <optional>
 #include <tuple>
+#include <type_traits>
 
 #ifndef QTYPEINFO_H
 #define QTYPEINFO_H
diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index 7acb2ff027c..e925f37fb15 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -283,67 +283,67 @@ using QDebugIfHasDebugStreamContainer =
 template<typename T>
 inline QDebugIfHasDebugStreamContainer<QList<T>, T> operator<<(QDebug debug, const QList<T> &vec)
 {
-    return QtPrivate::printSequentialContainer(debug, "QList", vec);
+    return QtPrivate::printSequentialContainer(std::move(debug), "QList", vec);
 }
 
 template<typename T, qsizetype P>
 inline QDebugIfHasDebugStream<T> operator<<(QDebug debug, const QVarLengthArray<T, P> &vec)
 {
-    return QtPrivate::printSequentialContainer(debug, "QVarLengthArray", vec);
+    return QtPrivate::printSequentialContainer(std::move(debug), "QVarLengthArray", vec);
 }
 
 template <typename T, typename Alloc>
 inline QDebugIfHasDebugStream<T> operator<<(QDebug debug, const std::vector<T, Alloc> &vec)
 {
-    return QtPrivate::printSequentialContainer(debug, "std::vector", vec);
+    return QtPrivate::printSequentialContainer(std::move(debug), "std::vector", vec);
 }
 
 template <typename T, typename Alloc>
 inline QDebugIfHasDebugStream<T> operator<<(QDebug debug, const std::list<T, Alloc> &vec)
 {
-    return QtPrivate::printSequentialContainer(debug, "std::list", vec);
+    return QtPrivate::printSequentialContainer(std::move(debug), "std::list", vec);
 }
 
 template <typename T>
 inline QDebugIfHasDebugStream<T> operator<<(QDebug debug, std::initializer_list<T> list)
 {
-    return QtPrivate::printSequentialContainer(debug, "std::initializer_list", list);
+    return QtPrivate::printSequentialContainer(std::move(debug), "std::initializer_list", list);
 }
 
 template <typename Key, typename T, typename Compare, typename Alloc>
 inline QDebugIfHasDebugStream<Key, T> operator<<(QDebug debug, const std::map<Key, T, Compare, Alloc> &map)
 {
-    return QtPrivate::printSequentialContainer(debug, "std::map", map); // yes, sequential: *it is std::pair
+    return QtPrivate::printSequentialContainer(std::move(debug), "std::map", map); // yes, sequential: *it is std::pair
 }
 
 template <typename Key, typename T, typename Compare, typename Alloc>
 inline QDebugIfHasDebugStream<Key, T> operator<<(QDebug debug, const std::multimap<Key, T, Compare, Alloc> &map)
 {
-    return QtPrivate::printSequentialContainer(debug, "std::multimap", map); // yes, sequential: *it is std::pair
+    return QtPrivate::printSequentialContainer(std::move(debug), "std::multimap", map); // yes, sequential: *it is std::pair
 }
 
 template <class Key, class T>
 inline QDebugIfHasDebugStreamContainer<QMap<Key, T>, Key, T> operator<<(QDebug debug, const QMap<Key, T> &map)
 {
-    return QtPrivate::printAssociativeContainer(debug, "QMap", map);
+    return QtPrivate::printAssociativeContainer(std::move(debug), "QMap", map);
 }
 
 template <class Key, class T>
 inline QDebugIfHasDebugStreamContainer<QMultiMap<Key, T>, Key, T> operator<<(QDebug debug, const QMultiMap<Key, T> &map)
 {
-    return QtPrivate::printAssociativeContainer(debug, "QMultiMap", map);
+    return QtPrivate::printAssociativeContainer(std::move(debug), "QMultiMap", map);
 }
 
 template <class Key, class T>
 inline QDebugIfHasDebugStreamContainer<QHash<Key, T>, Key, T> operator<<(QDebug debug, const QHash<Key, T> &hash)
 {
-    return QtPrivate::printAssociativeContainer(debug, "QHash", hash);
+    return QtPrivate::printAssociativeContainer(std::move(debug), "QHash", hash);
 }
 
 template <class Key, class T>
 inline QDebugIfHasDebugStreamContainer<QMultiHash<Key, T>, Key, T> operator<<(QDebug debug, const QMultiHash<Key, T> &hash)
 {
-    return QtPrivate::printAssociativeContainer(debug, "QMultiHash", hash);
+    return QtPrivate::printAssociativeContainer(std::move(debug), "QMultiHash", hash);
 }
 
 template <class T1, class T2>
@@ -357,7 +357,7 @@ inline QDebugIfHasDebugStream<T1, T2> operator<<(QDebug debug, const std::pair<T
 template <typename T>
 inline QDebugIfHasDebugStreamContainer<QSet<T>, T> operator<<(QDebug debug, const QSet<T> &set)
 {
-    return QtPrivate::printSequentialContainer(debug, "QSet", set);
+    return QtPrivate::printSequentialContainer(std::move(debug), "QSet", set);
 }
 
 template <class T>
diff --git a/src/corelib/io/qloggingregistry.cpp b/src/corelib/io/qloggingregistry.cpp
index 98057222138..3d8c85dceeb 100644
--- a/src/corelib/io/qloggingregistry.cpp
+++ b/src/corelib/io/qloggingregistry.cpp
@@ -347,8 +347,8 @@ void QLoggingRegistry::unregisterCategory(QLoggingCategory *cat)
     for enabling debugging by default for category \a categoryName. The
     category name must start with "qt."
 */
-void QLoggingRegistry::registerEnvironmentOverrideForCategory(QByteArrayView categoryName,
-                                                              QByteArrayView environment)
+void QLoggingRegistry::registerEnvironmentOverrideForCategory(const char *categoryName,
+                                                              const char *environment)
 {
     qtCategoryEnvironmentOverrides.insert(categoryName, environment);
 }
@@ -442,7 +442,7 @@ void QLoggingRegistry::defaultCategoryFilter(QLoggingCategory *cat)
             if (it == reg->qtCategoryEnvironmentOverrides.end())
                 debug = false;
             else
-                debug = qEnvironmentVariableIntValue(it.value().data());
+                debug = qEnvironmentVariableIntValue(it.value());
         }
     }
 
diff --git a/src/corelib/io/qloggingregistry_p.h b/src/corelib/io/qloggingregistry_p.h
index 69ed1a4f96e..aa38ed895be 100644
--- a/src/corelib/io/qloggingregistry_p.h
+++ b/src/corelib/io/qloggingregistry_p.h
@@ -97,7 +97,7 @@ public:
 #ifndef QT_BUILD_INTERNAL
     Q_CORE_EXPORT   // always export from QtCore
 #endif
-    void registerEnvironmentOverrideForCategory(QByteArrayView categoryName, QByteArrayView environment);
+    void registerEnvironmentOverrideForCategory(const char *categoryName, const char *environment);
 
     void setApiRules(const QString &content);
 
@@ -127,7 +127,7 @@ private:
     QList<QLoggingRule> ruleSets[NumRuleSets];
     QHash<QLoggingCategory *, QtMsgType> categories;
     QLoggingCategory::CategoryFilter categoryFilter;
-    QMap<QByteArrayView, QByteArrayView> qtCategoryEnvironmentOverrides;
+    QMap<QByteArrayView, const char *> qtCategoryEnvironmentOverrides;
 
     friend class ::tst_QLoggingRegistry;
 };
@@ -140,12 +140,12 @@ public:
     {}
 
 private:
-    static const char *registerOverride(QByteArrayView categoryName, QByteArrayView environment)
+    static const char *registerOverride(const char *categoryName, const char *environment)
     {
         QLoggingRegistry *c = QLoggingRegistry::instance();
         if (c)
             c->registerEnvironmentOverrideForCategory(categoryName, environment);
-        return categoryName.data();
+        return categoryName;
     }
 };
 
diff --git a/src/corelib/io/qsettings.cpp b/src/corelib/io/qsettings.cpp
index 41266d8219f..3c74fcb634d 100644
--- a/src/corelib/io/qsettings.cpp
+++ b/src/corelib/io/qsettings.cpp
@@ -1494,6 +1494,8 @@ void QConfFileSettingsPrivate::syncConfFile(QConfFile *confFile)
     }
 }
 
+namespace SettingsImpl {
+
 enum { Space = 0x1, Special = 0x2 };
 
 static const char charTraits[256] =
@@ -1520,10 +1522,15 @@ static const char charTraits[256] =
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 };
 
+} // namespace SettingsImpl
+
+using SettingsImpl::charTraits;
+
 bool QConfFileSettingsPrivate::readIniLine(QByteArrayView data, qsizetype &dataPos,
                                            qsizetype &lineStart, qsizetype &lineLen,
                                            qsizetype &equalsPos)
 {
+    using namespace SettingsImpl;
     qsizetype dataLen = data.size();
     bool inQuotes = false;
 
diff --git a/src/corelib/kernel/qeventdispatcher_wasm_p.h b/src/corelib/kernel/qeventdispatcher_wasm_p.h
index 9ae92c811be..b2057af6cb7 100644
--- a/src/corelib/kernel/qeventdispatcher_wasm_p.h
+++ b/src/corelib/kernel/qeventdispatcher_wasm_p.h
@@ -50,7 +50,7 @@ public:
     void interrupt() override;
     void wakeUp() override;
 
-    static void runOnMainThreadAsync(std::function<void(void)> fn);
+    static void runOnMainThread(std::function<void(void)> fn);
     static void socketSelect(int timeout, int socket, bool waitForRead, bool waitForWrite,
                             bool *selectForRead, bool *selectForWrite, bool *socketDisconnect);
 protected:
@@ -87,7 +87,7 @@ private:
 
     static void run(std::function<void(void)> fn);
     static void runAsync(std::function<void(void)> fn);
-    static void runOnMainThread(std::function<void(void)> fn);
+    static void runOnMainThreadAsync(std::function<void(void)> fn);
 
     static QEventDispatcherWasm *g_mainThreadEventDispatcher;
 
diff --git a/src/corelib/kernel/qmetaobject.cpp b/src/corelib/kernel/qmetaobject.cpp
index 9c7c70a6c88..792fe986563 100644
--- a/src/corelib/kernel/qmetaobject.cpp
+++ b/src/corelib/kernel/qmetaobject.cpp
@@ -2338,7 +2338,7 @@ QMetaMethod::MethodType QMetaMethod::methodType() const
     \since 5.0
 
     Returns the meta-method that corresponds to the given \a signal, or an
-    invalid QMetaMethod if \a signal is not a signal of the class.
+    invalid QMetaMethod if \a signal is \c{nullptr} or not a signal of the class.
 
     Example:
 
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 65390d83fc8..a2e9b23ac6c 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -252,7 +252,7 @@ QObjectList QObjectPrivate::receiverList(const char *signal) const
 {
     QObjectList returnValue;
     int signal_index = signalIndex(signal);
-    ConnectionData *cd = connections.loadRelaxed();
+    ConnectionData *cd = connections.loadAcquire();
     if (signal_index < 0 || !cd)
         return returnValue;
     if (signal_index < cd->signalVectorCount()) {
@@ -281,13 +281,17 @@ QObjectList QObjectPrivate::senderList() const
     return returnValue;
 }
 
+/*!
+  \internal
+  The signalSlotLock() of the sender must be locked while calling this function
+*/
 inline void QObjectPrivate::ensureConnectionData()
 {
     if (connections.loadRelaxed())
         return;
     ConnectionData *cd = new ConnectionData;
     cd->ref.ref();
-    connections.storeRelaxed(cd);
+    connections.storeRelease(cd);
 }
 
 /*!
@@ -452,7 +456,7 @@ bool QObjectPrivate::isSignalConnected(uint signalIndex, bool checkDeclarative)
     if (checkDeclarative && isDeclarativeSignalConnected(signalIndex))
         return true;
 
-    ConnectionData *cd = connections.loadRelaxed();
+    ConnectionData *cd = connections.loadAcquire();
     if (!cd)
         return false;
     SignalVector *signalVector = cd->signalVector.loadRelaxed();
@@ -475,7 +479,7 @@ bool QObjectPrivate::isSignalConnected(uint signalIndex, bool checkDeclarative)
 
 bool QObjectPrivate::maybeSignalConnected(uint signalIndex) const
 {
-    ConnectionData *cd = connections.loadRelaxed();
+    ConnectionData *cd = connections.loadAcquire();
     if (!cd)
         return false;
     SignalVector *signalVector = cd->signalVector.loadRelaxed();
@@ -1015,8 +1019,8 @@ void QObjectPrivate::clearBindingStorage()
     outside the parent. If you still do, the destroyed() signal gives
     you an opportunity to detect when an object is destroyed.
 
-    \warning Deleting a QObject while pending events are waiting to
-    be delivered can cause a crash. You must not delete the QObject
+    \warning Deleting a QObject while it is handling an event
+    delivered to it can cause a crash. You must not delete the QObject
     directly if it exists in a different thread than the one currently
     executing. Use deleteLater() instead, which will cause the event
     loop to delete the object after all pending events have been
@@ -1065,7 +1069,7 @@ QObject::~QObject()
     if (!d->isDeletingChildren && d->declarativeData && QAbstractDeclarativeData::destroyed)
         QAbstractDeclarativeData::destroyed(d->declarativeData, this);
 
-    QObjectPrivate::ConnectionData *cd = d->connections.loadRelaxed();
+    QObjectPrivate::ConnectionData *cd = d->connections.loadAcquire();
     if (cd) {
         if (cd->currentSender) {
             cd->currentSender->receiverDeleted();
@@ -1429,11 +1433,13 @@ bool QObject::event(QEvent *e)
         {
             QAbstractMetaCallEvent *mce = static_cast<QAbstractMetaCallEvent*>(e);
 
-            if (!d_func()->connections.loadRelaxed()) {
+            QObjectPrivate::ConnectionData *connections = d_func()->connections.loadAcquire();
+            if (!connections) {
                 QMutexLocker locker(signalSlotLock(this));
                 d_func()->ensureConnectionData();
+                connections = d_func()->connections.loadRelaxed();
             }
-            QObjectPrivate::Sender sender(this, const_cast<QObject*>(mce->sender()), mce->signalId());
+            QObjectPrivate::Sender sender(this, const_cast<QObject*>(mce->sender()), mce->signalId(), connections);
 
             mce->placeMetaCall(this);
             break;
@@ -1766,7 +1772,7 @@ void QObjectPrivate::setThreadData_helper(QThreadData *currentData, QThreadData
     }
 
     // the current emitting thread shouldn't restore currentSender after calling moveToThread()
-    ConnectionData *cd = connections.loadRelaxed();
+    ConnectionData *cd = connections.loadAcquire();
     if (cd) {
         if (cd->currentSender) {
             cd->currentSender->receiverDeleted();
@@ -2709,8 +2715,8 @@ int QObject::receivers(const char *signal) const
                                                              signal_index);
         }
 
-        QObjectPrivate::ConnectionData *cd = d->connections.loadRelaxed();
         QMutexLocker locker(signalSlotLock(this));
+        QObjectPrivate::ConnectionData *cd = d->connections.loadRelaxed();
         if (cd && signal_index < cd->signalVectorCount()) {
             const QObjectPrivate::Connection *c = cd->signalVector.loadRelaxed()->at(signal_index).first.loadRelaxed();
             while (c) {
@@ -3968,8 +3974,8 @@ void doActivate(QObject *sender, int signal_index, void **argv)
 
     bool senderDeleted = false;
     {
-    Q_ASSERT(sp->connections.loadAcquire());
-    QObjectPrivate::ConnectionDataPointer connections(sp->connections.loadRelaxed());
+    Q_ASSERT(sp->connections.loadRelaxed());
+    QObjectPrivate::ConnectionDataPointer connections(sp->connections.loadAcquire());
     QObjectPrivate::SignalVector *signalVector = connections->signalVector.loadRelaxed();
 
     const QObjectPrivate::ConnectionList *list;
@@ -4045,7 +4051,9 @@ void doActivate(QObject *sender, int signal_index, void **argv)
             if (c->isSingleShot && !QObjectPrivate::removeConnection(c))
                 continue;
 
-            QObjectPrivate::Sender senderData(receiverInSameThread ? receiver : nullptr, sender, signal_index);
+            QObjectPrivate::Sender senderData(
+                    receiverInSameThread ? receiver : nullptr, sender, signal_index,
+                    receiverInSameThread ? QObjectPrivate::get(receiver)->connections.loadAcquire() : nullptr);
 
             if (c->isSlotObject) {
                 SlotObjectGuard obj{c->slotObj};
@@ -4094,7 +4102,7 @@ void doActivate(QObject *sender, int signal_index, void **argv)
             senderDeleted = true;
     }
     if (!senderDeleted) {
-        sp->connections.loadRelaxed()->cleanOrphanedConnections(sender);
+        sp->connections.loadAcquire()->cleanOrphanedConnections(sender);
 
         if (callbacks_enabled && signal_spy_set->signal_end_callback != nullptr)
             signal_spy_set->signal_end_callback(sender, signal_index);
@@ -5154,9 +5162,9 @@ QMetaObject::Connection QObjectPrivate::connectImpl(const QObject *sender, int s
     QOrderedMutexLocker locker(signalSlotLock(sender),
                                signalSlotLock(receiver));
 
-    if (type & Qt::UniqueConnection && slot && QObjectPrivate::get(s)->connections.loadRelaxed()) {
+    if (type & Qt::UniqueConnection && slot) {
         QObjectPrivate::ConnectionData *connections = QObjectPrivate::get(s)->connections.loadRelaxed();
-        if (connections->signalVectorCount() > signal_index) {
+        if (connections && connections->signalVectorCount() > signal_index) {
             const QObjectPrivate::Connection *c2 = connections->signalVector.loadRelaxed()->at(signal_index).first.loadRelaxed();
 
             while (c2) {
@@ -5433,7 +5441,7 @@ inline bool QObjectPrivate::removeConnection(QObjectPrivate::Connection *c)
 QtPrivate::QPropertyAdaptorSlotObject *
 QObjectPrivate::getPropertyAdaptorSlotObject(const QMetaProperty &property)
 {
-    if (auto conns = connections.loadRelaxed()) {
+    if (auto conns = connections.loadAcquire()) {
         Q_Q(QObject);
         const QMetaObject *metaObject = q->metaObject();
         int signal_index = methodIndexToSignalIndex(&metaObject, property.notifySignalIndex());
diff --git a/src/corelib/kernel/qobject_p_p.h b/src/corelib/kernel/qobject_p_p.h
index d79ce7e2b93..537ea55f4d7 100644
--- a/src/corelib/kernel/qobject_p_p.h
+++ b/src/corelib/kernel/qobject_p_p.h
@@ -215,19 +215,18 @@ struct QObjectPrivate::ConnectionData
 
 struct QObjectPrivate::Sender
 {
-    Sender(QObject *receiver, QObject *sender, int signal)
+    Sender(QObject *receiver, QObject *sender, int signal, ConnectionData *receiverConnections)
         : receiver(receiver), sender(sender), signal(signal)
     {
-        if (receiver) {
-            ConnectionData *cd = receiver->d_func()->connections.loadRelaxed();
-            previous = cd->currentSender;
-            cd->currentSender = this;
+        if (receiverConnections) {
+            previous = receiverConnections->currentSender;
+            receiverConnections->currentSender = this;
         }
     }
     ~Sender()
     {
         if (receiver)
-            receiver->d_func()->connections.loadRelaxed()->currentSender = previous;
+            receiver->d_func()->connections.loadAcquire()->currentSender = previous;
     }
     void receiverDeleted()
     {
@@ -237,7 +236,7 @@ struct QObjectPrivate::Sender
             s = s->previous;
         }
     }
-    Sender *previous;
+    Sender *previous = nullptr;
     QObject *receiver;
     QObject *sender;
     int signal;
diff --git a/src/corelib/kernel/qproperty.cpp b/src/corelib/kernel/qproperty.cpp
index 5e78489fdae..68f6f424104 100644
--- a/src/corelib/kernel/qproperty.cpp
+++ b/src/corelib/kernel/qproperty.cpp
@@ -732,13 +732,6 @@ void QPropertyObserverPointer::setChangeHandler(QPropertyObserver::ChangeHandler
     ptr->next.setTag(QPropertyObserver::ObserverNotifiesChangeHandler);
 }
 
-void QPropertyObserverPointer::setBindingToNotify(QPropertyBindingPrivate *binding)
-{
-    Q_ASSERT(ptr->next.tag() != QPropertyObserver::ObserverIsPlaceholder);
-    ptr->binding = binding;
-    ptr->next.setTag(QPropertyObserver::ObserverNotifiesBinding);
-}
-
 /*!
     \internal
     The same as as setBindingToNotify, but assumes that the tag is already correct.
diff --git a/src/corelib/kernel/qproperty_p.h b/src/corelib/kernel/qproperty_p.h
index 77a744097eb..d8301e98852 100644
--- a/src/corelib/kernel/qproperty_p.h
+++ b/src/corelib/kernel/qproperty_p.h
@@ -134,7 +134,13 @@ struct QPropertyObserverPointer
         unlink_common();
     }
 
-    void setBindingToNotify(QPropertyBindingPrivate *binding);
+    void setBindingToNotify(QPropertyBindingPrivate *binding)
+    {
+        Q_ASSERT(ptr->next.tag() != QPropertyObserver::ObserverIsPlaceholder);
+        ptr->binding = binding;
+        ptr->next.setTag(QPropertyObserver::ObserverNotifiesBinding);
+    }
+
     void setBindingToNotify_unsafe(QPropertyBindingPrivate *binding);
     void setChangeHandler(QPropertyObserver::ChangeHandler changeHandler);
 
@@ -937,7 +943,15 @@ QBindingObserverPtr::QBindingObserverPtr(QPropertyObserver *observer) noexcept :
     QPropertyObserverPointer{d}.binding()->addRef();
 }
 
-QBindingObserverPtr::~QBindingObserverPtr() { if (d)  QPropertyObserverPointer{d}.binding()->deref(); }
+QBindingObserverPtr::~QBindingObserverPtr()
+{
+    if (!d)
+        return;
+
+    QPropertyBindingPrivate *bindingPrivate = binding();
+    if (!bindingPrivate->deref())
+        QPropertyBindingPrivate::destroyAndFreeMemory(bindingPrivate);
+}
 
 QPropertyBindingPrivate *QBindingObserverPtr::binding() const noexcept { return QPropertyObserverPointer{d}.binding(); }
 
diff --git a/src/corelib/mimetypes/mime/hexdump.ps1 b/src/corelib/mimetypes/mime/hexdump.ps1
index 01d386fa821..26fb9dd6e65 100644
--- a/src/corelib/mimetypes/mime/hexdump.ps1
+++ b/src/corelib/mimetypes/mime/hexdump.ps1
@@ -1,5 +1,5 @@
 # Copyright (C) 2019 Intel Corporation.
-# SPDX-License-Identifier: LicenseRef-Qt-Commercial
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
 param([String]$path, [String]$orig)
 
diff --git a/src/corelib/mimetypes/qmimedatabase.cpp b/src/corelib/mimetypes/qmimedatabase.cpp
index e196b778125..8aea2ff8455 100644
--- a/src/corelib/mimetypes/qmimedatabase.cpp
+++ b/src/corelib/mimetypes/qmimedatabase.cpp
@@ -12,7 +12,6 @@
 
 #include <private/qfilesystementry_p.h>
 
-#include <QtCore/QMap>
 #include <QtCore/QFile>
 #include <QtCore/QFileInfo>
 #include <QtCore/QStandardPaths>
diff --git a/src/corelib/mimetypes/qmimemagicrule.cpp b/src/corelib/mimetypes/qmimemagicrule.cpp
index 9111f1f0e9d..020e2d5a228 100644
--- a/src/corelib/mimetypes/qmimemagicrule.cpp
+++ b/src/corelib/mimetypes/qmimemagicrule.cpp
@@ -8,7 +8,6 @@
 
 #include "qmimetypeparser_p.h"
 #include <QtCore/QList>
-#include <QtCore/QMap>
 #include <QtCore/QDebug>
 #include <qendian.h>
 
diff --git a/src/corelib/serialization/qcbormap.h b/src/corelib/serialization/qcbormap.h
index 523ef9ea349..e9918a30a56 100644
--- a/src/corelib/serialization/qcbormap.h
+++ b/src/corelib/serialization/qcbormap.h
@@ -40,6 +40,7 @@ public:
 
         constexpr Iterator() = default;
         constexpr Iterator(const Iterator &) = default;
+        ~Iterator() = default;
         Iterator &operator=(const Iterator &other)
         {
             // rebind the reference
@@ -100,6 +101,7 @@ public:
 
         constexpr ConstIterator() = default;
         constexpr ConstIterator(const ConstIterator &) = default;
+        ~ConstIterator() = default;
         ConstIterator &operator=(const ConstIterator &other)
         {
             // rebind the reference
diff --git a/src/corelib/serialization/qdatastream.cpp b/src/corelib/serialization/qdatastream.cpp
index b364f7f9e2f..cc7a3604cf6 100644
--- a/src/corelib/serialization/qdatastream.cpp
+++ b/src/corelib/serialization/qdatastream.cpp
@@ -1056,13 +1056,15 @@ QDataStream &QDataStream::readBytes(char *&s, uint &l)
     if (len == 0)
         return *this;
 
-    const quint32 Step = 1024 * 1024;
+    quint32 step = 1024 * 1024;
     quint32 allocated = 0;
     char *prevBuf = nullptr;
     char *curBuf = nullptr;
 
+    constexpr quint32 MaxBlockSize = std::numeric_limits<int>::max();
     do {
-        int blockSize = qMin(Step, len - allocated);
+        const quint32 sz = qMin(step, len - allocated);
+        int blockSize = qMin(sz, MaxBlockSize);
         prevBuf = curBuf;
         curBuf = new char[allocated + blockSize + 1];
         if (prevBuf) {
@@ -1074,6 +1076,7 @@ QDataStream &QDataStream::readBytes(char *&s, uint &l)
             return *this;
         }
         allocated += blockSize;
+        step *= 2;
     } while (allocated < len);
 
     s = curBuf;
diff --git a/src/corelib/serialization/qxmlstream.cpp b/src/corelib/serialization/qxmlstream.cpp
index 48839d832e6..21153603525 100644
--- a/src/corelib/serialization/qxmlstream.cpp
+++ b/src/corelib/serialization/qxmlstream.cpp
@@ -2981,54 +2981,80 @@ void QXmlStreamWriterPrivate::write(QAnyStringView s)
 
 void QXmlStreamWriterPrivate::writeEscaped(QAnyStringView s, bool escapeWhitespace)
 {
+    struct NextLatin1 {
+        char32_t operator()(const char *&it, const char *) const
+        { return uchar(*it++); }
+    };
+    struct NextUtf8 {
+        char32_t operator()(const char *&it, const char *end) const
+        {
+            uchar uc = *it++;
+            char32_t utf32 = 0;
+            char32_t *output = &utf32;
+            qsizetype n = QUtf8Functions::fromUtf8<QUtf8BaseTraits>(uc, output, it, end);
+            return n < 0 ? 0 : utf32;
+        }
+    };
+    struct NextUtf16 {
+        char32_t operator()(const QChar *&it, const QChar *) const
+        {
+            return (it++)->unicode();
+        }
+    };
+
     QString escaped;
     escaped.reserve(s.size());
     s.visit([&] (auto s) {
         using View = decltype(s);
+        using Decoder = std::conditional_t<std::is_same_v<View, QLatin1StringView>, NextLatin1,
+                            std::conditional_t<std::is_same_v<View, QUtf8StringView>, NextUtf8, NextUtf16>>;
 
         auto it = s.begin();
         const auto end = s.end();
+        Decoder decoder;
 
         while (it != end) {
             QLatin1StringView replacement;
             auto mark = it;
 
             while (it != end) {
-                if (*it == u'<') {
+                auto next_it = it;
+                char32_t uc = decoder(next_it, end);
+                if (uc == u'<') {
                     replacement = "&lt;"_L1;
                     break;
-                } else if (*it == u'>') {
+                } else if (uc == u'>') {
                     replacement = "&gt;"_L1;
                     break;
-                } else if (*it == u'&') {
+                } else if (uc == u'&') {
                     replacement = "&amp;"_L1;
                     break;
-                } else if (*it == u'\"') {
+                } else if (uc == u'\"') {
                     replacement = "&quot;"_L1;
                     break;
-                } else if (*it == u'\t') {
+                } else if (uc == u'\t') {
                     if (escapeWhitespace) {
                         replacement = "&#9;"_L1;
                         break;
                     }
-                } else if (*it == u'\n') {
+                } else if (uc == u'\n') {
                     if (escapeWhitespace) {
                         replacement = "&#10;"_L1;
                         break;
                     }
-                } else if (*it == u'\v' || *it == u'\f') {
+                } else if (uc == u'\v' || uc == u'\f') {
                     hasEncodingError = true;
                     break;
-                } else if (*it == u'\r') {
+                } else if (uc == u'\r') {
                     if (escapeWhitespace) {
                         replacement = "&#13;"_L1;
                         break;
                     }
-                } else if (*it <= u'\x1F' || *it >= u'\uFFFE') {
+                } else if (uc <= u'\x1F' || uc == u'\uFFFE' || uc == u'\uFFFF') {
                     hasEncodingError = true;
                     break;
                 }
-                ++it;
+                it = next_it;
             }
 
             escaped.append(View{mark, it});
diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp
index 8faa130d38f..e6399baf909 100644
--- a/src/corelib/text/qbytearray.cpp
+++ b/src/corelib/text/qbytearray.cpp
@@ -1342,6 +1342,9 @@ QByteArray &QByteArray::operator=(const QByteArray & other) noexcept
     \overload
 
     Assigns \a str to this byte array.
+
+    \a str is assumed to point to a null-terminated string, and its length is
+    determined dynamically.
 */
 
 QByteArray &QByteArray::operator=(const char *str)
diff --git a/src/corelib/text/qlocale.cpp b/src/corelib/text/qlocale.cpp
index 4466a460b23..1a2fbee2357 100644
--- a/src/corelib/text/qlocale.cpp
+++ b/src/corelib/text/qlocale.cpp
@@ -109,18 +109,18 @@ QLocale::Language QLocalePrivate::codeToLanguage(QStringView code,
 
     auto searchCode = [codeBuf](auto f) {
         return std::find_if(languageCodeList.begin(), languageCodeList.end(),
-                            [=](const LanguageCodeEntry &i) { return f(i) == codeBuf; });
+                            [=](LanguageCodeEntry i) { return f(i) == codeBuf; });
     };
 
     if (codeTypes.testFlag(QLocale::ISO639Part1) && uc3 == 0) {
-        auto i = searchCode([](const LanguageCodeEntry &i) { return i.part1; });
+        auto i = searchCode([](LanguageCodeEntry i) { return i.part1; });
         if (i != languageCodeList.end())
             return QLocale::Language(std::distance(languageCodeList.begin(), i));
     }
 
     if (uc3 != 0) {
         if (codeTypes.testFlag(QLocale::ISO639Part2B)) {
-            auto i = searchCode([](const LanguageCodeEntry &i) { return i.part2B; });
+            auto i = searchCode([](LanguageCodeEntry i) { return i.part2B; });
             if (i != languageCodeList.end())
                 return QLocale::Language(std::distance(languageCodeList.begin(), i));
         }
@@ -129,13 +129,13 @@ QLocale::Language QLocalePrivate::codeToLanguage(QStringView code,
         // This is asserted in iso639_3.LanguageCodeData.
         if (codeTypes.testFlag(QLocale::ISO639Part2T)
             && !codeTypes.testFlag(QLocale::ISO639Part3)) {
-            auto i = searchCode([](const LanguageCodeEntry &i) { return i.part2T; });
+            auto i = searchCode([](LanguageCodeEntry i) { return i.part2T; });
             if (i != languageCodeList.end())
                 return QLocale::Language(std::distance(languageCodeList.begin(), i));
         }
 
         if (codeTypes.testFlag(QLocale::ISO639Part3)) {
-            auto i = searchCode([](const LanguageCodeEntry &i) { return i.part3; });
+            auto i = searchCode([](LanguageCodeEntry i) { return i.part3; });
             if (i != languageCodeList.end())
                 return QLocale::Language(std::distance(languageCodeList.begin(), i));
         }
@@ -250,7 +250,7 @@ struct LikelyPair
     QLocaleId value = QLocaleId { 0, 0, 0 };
 };
 
-bool operator<(const LikelyPair &lhs, const LikelyPair &rhs)
+bool operator<(LikelyPair lhs, LikelyPair rhs)
 {
     // Must match the comparison LocaleDataWriter.likelySubtags() uses when
     // sorting, see qtbase/util/locale_database.qlocalexml2cpp.py
@@ -461,7 +461,7 @@ QByteArray QLocalePrivate::bcp47Name(char separator) const
     return m_data->id().withLikelySubtagsRemoved().name(separator);
 }
 
-static qsizetype findLocaleIndexById(const QLocaleId &localeId)
+static qsizetype findLocaleIndexById(QLocaleId localeId)
 {
     qsizetype idx = locale_index[localeId.language_id];
     // If there are no locales for specified language (so we we've got the
diff --git a/src/corelib/text/qlocale.qdoc b/src/corelib/text/qlocale.qdoc
index fcc4ab4cfb1..f81c10a87fe 100644
--- a/src/corelib/text/qlocale.qdoc
+++ b/src/corelib/text/qlocale.qdoc
@@ -1153,7 +1153,7 @@
 */
 
 /*!
-    \fn QVariant QSystemLocale::query(QueryType type, QVariant in = QVariant()) const
+    \fn QVariant QSystemLocale::query(QueryType type, QVariant &&in = QVariant()) const
 
     Generic query method for locale data. Provides indirection.
     Denotes the \a type of the query
diff --git a/src/corelib/text/qlocale_mac.mm b/src/corelib/text/qlocale_mac.mm
index ec592616c53..9c3f7a4f31c 100644
--- a/src/corelib/text/qlocale_mac.mm
+++ b/src/corelib/text/qlocale_mac.mm
@@ -571,7 +571,7 @@ static QLocale::Language codeToLanguage(QStringView s)
     return QLocalePrivate::codeToLanguage(s);
 }
 
-QVariant QSystemLocale::query(QueryType type, QVariant in) const
+QVariant QSystemLocale::query(QueryType type, QVariant &&in) const
 {
     QMacAutoReleasePool pool;
 
diff --git a/src/corelib/text/qlocale_p.h b/src/corelib/text/qlocale_p.h
index cb1adfbe592..8a61dd77829 100644
--- a/src/corelib/text/qlocale_p.h
+++ b/src/corelib/text/qlocale_p.h
@@ -35,6 +35,7 @@ struct QLocaleData;
 // Subclassed by Android platform plugin:
 class Q_CORE_EXPORT QSystemLocale
 {
+    Q_DISABLE_COPY_MOVE(QSystemLocale)
     QSystemLocale *next = nullptr; // Maintains a stack.
 public:
     QSystemLocale();
@@ -98,7 +99,7 @@ public:
         StandaloneDayNameShort, // QString, in: int
         StandaloneDayNameNarrow // QString, in: int
     };
-    virtual QVariant query(QueryType type, QVariant in = QVariant()) const;
+    virtual QVariant query(QueryType type, QVariant &&in = QVariant()) const;
 
     virtual QLocale fallbackLocale() const;
     inline qsizetype fallbackLocaleIndex() const;
diff --git a/src/corelib/text/qlocale_unix.cpp b/src/corelib/text/qlocale_unix.cpp
index 6f6884d3661..a0c9ecc4341 100644
--- a/src/corelib/text/qlocale_unix.cpp
+++ b/src/corelib/text/qlocale_unix.cpp
@@ -124,7 +124,7 @@ QLocale QSystemLocale::fallbackLocale() const
     return QLocale(lang);
 }
 
-QVariant QSystemLocale::query(QueryType type, QVariant in) const
+QVariant QSystemLocale::query(QueryType type, QVariant &&in) const
 {
     QSystemLocaleData *d = qSystemLocaleData();
 
@@ -258,9 +258,10 @@ QVariant QSystemLocale::query(QueryType type, QVariant in) const
         return d->uiLanguages.isEmpty() ? QVariant() : QVariant(d->uiLanguages);
     }
     case StringToStandardQuotation:
-        return lc_messages.quoteString(qvariant_cast<QStringView>(in));
+        return lc_messages.quoteString(qvariant_cast<QStringView>(std::move(in)));
     case StringToAlternateQuotation:
-        return lc_messages.quoteString(qvariant_cast<QStringView>(in), QLocale::AlternateQuotation);
+        return lc_messages.quoteString(qvariant_cast<QStringView>(std::move(in)),
+                                       QLocale::AlternateQuotation);
     case ListToSeparatedString:
         return lc_messages.createSeparatedList(in.toStringList());
     case LocaleChanged:
diff --git a/src/corelib/text/qlocale_win.cpp b/src/corelib/text/qlocale_win.cpp
index 3454e859852..9ce9f9af4b0 100644
--- a/src/corelib/text/qlocale_win.cpp
+++ b/src/corelib/text/qlocale_win.cpp
@@ -837,7 +837,7 @@ QLocale QSystemLocale::fallbackLocale() const
     return QLocale(QString::fromLatin1(getWinLocaleName()));
 }
 
-QVariant QSystemLocale::query(QueryType type, QVariant in) const
+QVariant QSystemLocale::query(QueryType type, QVariant &&in) const
 {
     QSystemLocalePrivate *d = systemLocalePrivate();
     switch(type) {
diff --git a/src/corelib/text/qstringconverter.cpp b/src/corelib/text/qstringconverter.cpp
index 8b67cbeabce..a3a0b3c4f8c 100644
--- a/src/corelib/text/qstringconverter.cpp
+++ b/src/corelib/text/qstringconverter.cpp
@@ -1365,10 +1365,10 @@ QString QLocal8Bit::convertToUnicode_sys(QByteArrayView in, quint32 codePage,
     // encounter an error
     int nextIn = qt_saturate<int>(mblen);
     while (mblen > 0) {
-        const int nextOut = qt_saturate<int>(outlen);
         std::tie(out, outlen) = growOut(1); // Need space for at least one character
         if (!out)
             return {};
+        const int nextOut = qt_saturate<int>(outlen);
         len = MultiByteToWideChar(codePage, MB_ERR_INVALID_CHARS, mb, nextIn, out, nextOut);
         if (len) {
             mb += nextIn;
@@ -1576,9 +1576,11 @@ QByteArray QLocal8Bit::convertFromUnicode_sys(QStringView in, quint32 codePage,
                     // incomplete sequence, probably a Windows bug. We try to avoid that from
                     // happening by reducing the window size in that case. But let's keep this
                     // branch just in case of other bugs.
+#ifndef QT_NO_DEBUG
                     r = GetLastError();
                     fprintf(stderr,
                             "WideCharToMultiByte: Cannot convert multibyte text (error %d)\n", r);
+#endif // !QT_NO_DEBUG
                     break;
                 }
                 std::tie(out, outlen) = growOut(neededLength);
@@ -1964,7 +1966,7 @@ struct QStringConverterICU : QStringConverter
         const void *context;
         ucnv_getToUCallBack(icu_conv, &action, &context);
         if (context != state)
-             ucnv_setToUCallBack(icu_conv, action, &state, nullptr, nullptr, &err);
+             ucnv_setToUCallBack(icu_conv, action, state, nullptr, nullptr, &err);
 
         ucnv_toUnicode(icu_conv, &target, targetLimit, &source, sourceLimit, nullptr, flush, &err);
         // We did reserve enough space:
@@ -1997,7 +1999,7 @@ struct QStringConverterICU : QStringConverter
         const void *context;
         ucnv_getFromUCallBack(icu_conv, &action, &context);
         if (context != state)
-             ucnv_setFromUCallBack(icu_conv, action, &state, nullptr, nullptr, &err);
+             ucnv_setFromUCallBack(icu_conv, action, state, nullptr, nullptr, &err);
 
         ucnv_fromUnicode(icu_conv, &target, targetLimit, &source, sourceLimit, nullptr, flush, &err);
         // We did reserve enough space:
diff --git a/src/corelib/text/qstringconverter_p.h b/src/corelib/text/qstringconverter_p.h
index 40f9b62a3ee..da19fa70577 100644
--- a/src/corelib/text/qstringconverter_p.h
+++ b/src/corelib/text/qstringconverter_p.h
@@ -43,18 +43,27 @@ struct QUtf8BaseTraits
     static void appendByte(qchar8_t *&ptr, qchar8_t b)
     { *ptr++ = b; }
 
+    static uchar peekByte(const char *ptr, qsizetype n = 0)
+    { return ptr[n]; }
+
     static uchar peekByte(const uchar *ptr, qsizetype n = 0)
     { return ptr[n]; }
 
     static uchar peekByte(const qchar8_t *ptr, qsizetype n = 0)
     { return ptr[n]; }
 
+    static qptrdiff availableBytes(const char *ptr, const char *end)
+    { return end - ptr; }
+
     static qptrdiff availableBytes(const uchar *ptr, const uchar *end)
     { return end - ptr; }
 
     static qptrdiff availableBytes(const qchar8_t *ptr, const qchar8_t *end)
     { return end - ptr; }
 
+    static void advanceByte(const char *&ptr, qsizetype n = 1)
+    { ptr += n; }
+
     static void advanceByte(const uchar *&ptr, qsizetype n = 1)
     { ptr += n; }
 
diff --git a/src/corelib/text/qstringtokenizer.h b/src/corelib/text/qstringtokenizer.h
index 2b679608f91..7a627b45084 100644
--- a/src/corelib/text/qstringtokenizer.h
+++ b/src/corelib/text/qstringtokenizer.h
@@ -5,6 +5,7 @@
 
 #include <QtCore/qnamespace.h>
 #include <QtCore/qcontainerfwd.h>
+#include <iterator>
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/corelib/text/qt_attribution.json b/src/corelib/text/qt_attribution.json
index 0084ccc18d9..3ae1bd2925a 100644
--- a/src/corelib/text/qt_attribution.json
+++ b/src/corelib/text/qt_attribution.json
@@ -35,8 +35,8 @@
  available.",
     "Homepage": "https://cldr.unicode.org/",
     "Version": "v44.1",
-    "License": "Unicode License V3",
-    "LicenseId": "UNICODE-3.0",
+    "License": "Unicode License v3",
+    "LicenseId": "Unicode-3.0",
     "Copyright": "Copyright (C) 2004-2023 Unicode, Inc."
 }
 ]
diff --git a/src/corelib/thread/qfutureinterface.h b/src/corelib/thread/qfutureinterface.h
index 7e682e69b68..86b8cbd3484 100644
--- a/src/corelib/thread/qfutureinterface.h
+++ b/src/corelib/thread/qfutureinterface.h
@@ -452,7 +452,7 @@ template <>
 class QFutureInterface<void> : public QFutureInterfaceBase
 {
 public:
-    explicit QFutureInterface<void>(State initialState = NoState)
+    explicit QFutureInterface(State initialState = NoState)
         : QFutureInterfaceBase(initialState)
     { }
 
diff --git a/src/corelib/time/qtimezoneprivate_tz.cpp b/src/corelib/time/qtimezoneprivate_tz.cpp
index f1ea6128ae3..276291a4719 100644
--- a/src/corelib/time/qtimezoneprivate_tz.cpp
+++ b/src/corelib/time/qtimezoneprivate_tz.cpp
@@ -578,7 +578,12 @@ PosixZone PosixZone::parse(const char *&pos, const char *end)
     return {std::move(name), offset};
 }
 
-static auto validatePosixRule(const QByteArray &posixRule)
+/* Parse and check a POSIX rule.
+
+   By default a simple zone abbreviation with no offset information is accepted.
+   Set \a requireOffset to \c true to require that there be offset data present.
+*/
+static auto validatePosixRule(const QByteArray &posixRule, bool requireOffset = false)
 {
     // Format is described here:
     // http://www.gnu.org/software/libc/manual/html_node/TZ-Variable.html
@@ -590,15 +595,19 @@ static auto validatePosixRule(const QByteArray &posixRule)
         return fail;
 
     const char *begin = zoneinfo.begin();
-
-    // Updates begin to point after the name and offset it parses:
-    if (PosixZone::parse(begin, zoneinfo.end()).name.isEmpty())
-        return fail;
+    {
+        // Updates begin to point after the name and offset it parses:
+        const auto posix = PosixZone::parse(begin, zoneinfo.end());
+        if (posix.name.isEmpty())
+            return fail;
+        if (requireOffset && !posix.hasValidOffset())
+            return fail;
+    }
 
     if (good.hasDst) {
         if (begin >= zoneinfo.end())
             return fail;
-        // Expect a second name and offset after the first:
+        // Expect a second name (and optional offset) after the first:
         if (PosixZone::parse(begin, zoneinfo.end()).name.isEmpty())
             return fail;
     }
@@ -772,7 +781,7 @@ public:
     QTzTimeZoneCacheEntry fetchEntry(const QByteArray &ianaId);
 
 private:
-    QTzTimeZoneCacheEntry findEntry(const QByteArray &ianaId);
+    static QTzTimeZoneCacheEntry findEntry(const QByteArray &ianaId);
     QCache<QByteArray, QTzTimeZoneCacheEntry> m_cache;
     QMutex m_mutex;
 };
@@ -977,6 +986,8 @@ QTzTimeZoneCacheEntry QTzTimeZoneCache::fetchEntry(const QByteArray &ianaId)
 // Create a named time zone
 QTzTimeZonePrivate::QTzTimeZonePrivate(const QByteArray &ianaId)
 {
+    if (!isTimeZoneIdAvailable(ianaId)) // Avoid pointlessly creating cache entries
+        return;
     static QTzTimeZoneCache tzCache;
     auto entry = tzCache.fetchEntry(ianaId);
     if (entry.m_tranTimes.isEmpty() && entry.m_posixRule.isEmpty())
@@ -1239,7 +1250,11 @@ QTimeZonePrivate::Data QTzTimeZonePrivate::previousTransition(qint64 beforeMSecs
 
 bool QTzTimeZonePrivate::isTimeZoneIdAvailable(const QByteArray &ianaId) const
 {
-    return tzZones->contains(ianaId);
+    // Allow a POSIX rule as long as it has offset data. (This needs to reject a
+    // plain abbreviation, without offset, since claiming to support such zones
+    // would prevent the custom QTimeZone constructor from accepting such a
+    // name, as it doesn't want a custom zone to over-ride a "real" one.)
+    return tzZones->contains(ianaId) || validatePosixRule(ianaId, true).isValid;
 }
 
 QList<QByteArray> QTzTimeZonePrivate::availableTimeZoneIds() const
diff --git a/src/corelib/tools/qcontainertools_impl.h b/src/corelib/tools/qcontainertools_impl.h
index d380421170c..7efea45acd2 100644
--- a/src/corelib/tools/qcontainertools_impl.h
+++ b/src/corelib/tools/qcontainertools_impl.h
@@ -265,7 +265,11 @@ using IfAssociativeIteratorHasKeyAndValue =
 
 template <typename Iterator>
 using IfAssociativeIteratorHasFirstAndSecond =
-    std::enable_if_t<qxp::is_detected_v<FirstAndSecondTest, Iterator>, bool>;
+    std::enable_if_t<
+        std::conjunction_v<
+            std::negation<qxp::is_detected<KeyAndValueTest, Iterator>>,
+            qxp::is_detected<FirstAndSecondTest, Iterator>
+        >, bool>;
 
 template <typename T, typename U>
 using IfIsNotSame =
@@ -323,8 +327,7 @@ template <typename Container, typename T>
 auto sequential_erase_with_copy(Container &c, const T &t)
 {
     using CopyProxy = std::conditional_t<std::is_copy_constructible_v<T>, T, const T &>;
-    const T &tCopy = CopyProxy(t);
-    return sequential_erase(c, tCopy);
+    return sequential_erase(c, CopyProxy(t));
 }
 
 template <typename Container, typename T>
diff --git a/src/corelib/tools/qlist.h b/src/corelib/tools/qlist.h
index d61b90503a4..8ed4110bae7 100644
--- a/src/corelib/tools/qlist.h
+++ b/src/corelib/tools/qlist.h
@@ -109,8 +109,7 @@ public:
     public:
         using difference_type = qsizetype;
         using value_type = T;
-        // libstdc++ shipped with gcc < 11 does not have a fix for defect LWG 3346
-#if __cplusplus >= 202002L && (!defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE >= 11)
+#ifdef QT_COMPILER_HAS_LWG3346
         using iterator_concept = std::contiguous_iterator_tag;
         using element_type = value_type;
 #endif
@@ -180,8 +179,7 @@ public:
     public:
         using difference_type = qsizetype;
         using value_type = T;
-        // libstdc++ shipped with gcc < 11 does not have a fix for defect LWG 3346
-#if __cplusplus >= 202002L && (!defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE >= 11)
+#ifdef QT_COMPILER_HAS_LWG3346
         using iterator_concept = std::contiguous_iterator_tag;
         using element_type = const value_type;
 #endif
diff --git a/src/corelib/tools/quniquehandle_p.h b/src/corelib/tools/quniquehandle_p.h
index e31699a1229..7af1536c2ed 100644
--- a/src/corelib/tools/quniquehandle_p.h
+++ b/src/corelib/tools/quniquehandle_p.h
@@ -1,5 +1,5 @@
 // Copyright (C) 2023 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
 #ifndef QUNIQUEHANDLE_P_H
 #define QUNIQUEHANDLE_P_H