Merge branch 're-import-kdsag' into calamares

FIXES #1997

.reuse/dep5

@@ -15,6 +15,10 @@ Files: man/calamares.8
 License: GPL-3.0-or-later
 Copyright: 2017 Jonathan Carter <jcarter@linux.com>
 
+Files: 3rdparty/kdsingleapplication/*
+License: MIT
+Copyright: Copyright (C) 2019-2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@ kdab.com
+
 ### BUILD ARTIFACTS / NOT SOURCE
 #
 # QRC Files are basically build artifacts

3rdparty/kdsingleapplication/CMakeLists.txt

@@ -0,0 +1,26 @@
+set(KDSINGLEAPPLICATION_STATIC ON)
+
+set(KDSINGLEAPPLICATION_SRCS kdsingleapplication.cpp kdsingleapplication_localsocket.cpp)
+
+set(KDSINGLEAPPLICATION_INSTALLABLE_INCLUDES kdsingleapplication.h kdsingleapplication_lib.h)
+
+set(KDSINGLEAPPLICATION_NON_INSTALLABLE_INCLUDES kdsingleapplication_localsocket_p.h)
+
+if(KDSINGLEAPPLICATION_STATIC)
+    add_library(kdsingleapplication STATIC ${KDSINGLEAPPLICATION_INSTALLABLE_INCLUDES} ${KDSINGLEAPPLICATION_SRCS})
+    target_compile_definitions(kdsingleapplication PUBLIC KDSINGLEAPPLICATION_STATIC_BUILD)
+else()
+    add_library(kdsingleapplication SHARED ${KDSINGLEAPPLICATION_INSTALLABLE_INCLUDES} ${KDSINGLEAPPLICATION_SRCS})
+    target_compile_definitions(kdsingleapplication PRIVATE KDSINGLEAPPLICATION_SHARED_BUILD)
+endif()
+set_target_properties( kdsingleapplication PROPERTIES AUTOMOC TRUE )
+
+set(KDSINGLEAPPLICATION_INCLUDEDIR ${CMAKE_INSTALL_INCLUDEDIR}/kdsingleapplication)
+
+target_include_directories(
+    kdsingleapplication
+    PUBLIC $<INSTALL_INTERFACE:${KDSINGLEAPPLICATION_INCLUDEDIR}> $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
+    PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+target_link_libraries(kdsingleapplication Qt5::Core Qt5::Network)

3rdparty/kdsingleapplication/KDSingleApplicationConfig.cmake.in

@@ -0,0 +1,7 @@
+include(CMakeFindDependencyMacro)
+
+find_dependency(Qt5Widgets REQUIRED)
+find_dependency(Qt5Network REQUIRED)
+
+# Add the targets file
+include("${CMAKE_CURRENT_LIST_DIR}/KDSingleApplicationTargets.cmake")

3rdparty/kdsingleapplication/LICENSE.MIT.txt

@@ -0,0 +1,22 @@
+MIT License
+
+Copyright (C) 2019-2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

3rdparty/kdsingleapplication/kdsingleapplication.cpp

@@ -0,0 +1,123 @@
+/*
+    MIT License
+
+    Copyright (C) 2019-2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+*/
+
+#include "kdsingleapplication.h"
+
+#include <QtCore/QCoreApplication>
+#include <QtCore/QFileInfo>
+
+// TODO: make this pluggable.
+#include "kdsingleapplication_localsocket_p.h"
+
+// Avoiding dragging in Qt private APIs for now, so this does not inherit
+// from QObjectPrivate.
+class KDSingleApplicationPrivate
+{
+public:
+    explicit KDSingleApplicationPrivate(const QString &name, KDSingleApplication *q);
+
+    void initialize();
+
+    QString name() const
+    {
+        return m_name;
+    }
+
+    bool isPrimaryInstance() const
+    {
+        return m_impl.isPrimaryInstance();
+    }
+
+    bool sendMessage(const QByteArray &message, int timeout)
+    {
+        return m_impl.sendMessage(message, timeout);
+    }
+
+private:
+    Q_DECLARE_PUBLIC(KDSingleApplication)
+
+    KDSingleApplication *q_ptr;
+    QString m_name;
+
+    KDSingleApplicationLocalSocket m_impl;
+};
+
+KDSingleApplicationPrivate::KDSingleApplicationPrivate(const QString &name, KDSingleApplication *q)
+    : q_ptr(q)
+    , m_name(name)
+    , m_impl(name)
+{
+    if (Q_UNLIKELY(name.isEmpty()))
+        qFatal("KDSingleApplication requires a non-empty application name");
+
+    if (isPrimaryInstance()) {
+        QObject::connect(&m_impl, &KDSingleApplicationLocalSocket::messageReceived,
+                         q, &KDSingleApplication::messageReceived);
+    }
+}
+
+static QString extractExecutableName(const QString &applicationFilePath)
+{
+    return QFileInfo(applicationFilePath).fileName();
+}
+
+KDSingleApplication::KDSingleApplication(QObject *parent)
+    : KDSingleApplication(extractExecutableName(QCoreApplication::applicationFilePath()), parent)
+{
+}
+
+KDSingleApplication::KDSingleApplication(const QString &name, QObject *parent)
+    : QObject(parent)
+    , d_ptr(new KDSingleApplicationPrivate(name, this))
+{
+}
+
+QString KDSingleApplication::name() const
+{
+    Q_D(const KDSingleApplication);
+    return d->name();
+}
+
+bool KDSingleApplication::isPrimaryInstance() const
+{
+    Q_D(const KDSingleApplication);
+    return d->isPrimaryInstance();
+}
+
+bool KDSingleApplication::sendMessage(const QByteArray &message)
+{
+    return sendMessageWithTimeout(message, 5000);
+}
+
+bool KDSingleApplication::sendMessageWithTimeout(const QByteArray &message, int timeout)
+{
+    Q_ASSERT(!isPrimaryInstance());
+
+    Q_D(KDSingleApplication);
+    return d->sendMessage(message, timeout);
+}
+
+
+KDSingleApplication::~KDSingleApplication() = default;
+

3rdparty/kdsingleapplication/kdsingleapplication.h

@@ -0,0 +1,62 @@
+/*
+    MIT License
+
+    Copyright (C) 2019-2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+*/
+#ifndef KDSINGLEAPPLICATION_H
+#define KDSINGLEAPPLICATION_H
+
+#include <QtCore/QObject>
+
+#include <memory>
+
+#include "kdsingleapplication_lib.h"
+
+class KDSingleApplicationPrivate;
+
+class KDSINGLEAPPLICATION_EXPORT KDSingleApplication : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QString name READ name CONSTANT)
+    Q_PROPERTY(bool isPrimaryInstance READ isPrimaryInstance CONSTANT)
+
+public:
+    explicit KDSingleApplication(QObject *parent = nullptr);
+    explicit KDSingleApplication(const QString &name, QObject *parent = nullptr);
+    ~KDSingleApplication();
+
+    QString name() const;
+    bool isPrimaryInstance() const;
+
+public Q_SLOTS:
+    // avoid default arguments and overloads, as they don't mix with connections
+    bool sendMessage(const QByteArray &message);
+    bool sendMessageWithTimeout(const QByteArray &message, int timeout);
+
+Q_SIGNALS:
+    void messageReceived(const QByteArray &message);
+
+private:
+    Q_DECLARE_PRIVATE(KDSingleApplication)
+    std::unique_ptr<KDSingleApplicationPrivate> d_ptr;
+};
+
+#endif // KDSINGLEAPPLICATION_H

3rdparty/kdsingleapplication/kdsingleapplication_lib.h

@@ -0,0 +1,37 @@
+/*
+    MIT License
+
+    Copyright (C) 2019-2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+*/
+#ifndef KDSINGLEAPPLICATION_LIB_H
+#define KDSINGLEAPPLICATION_LIB_H
+
+#include <QtCore/QtGlobal>
+
+#if defined(KDSINGLEAPPLICATION_STATIC_BUILD)
+#define KDSINGLEAPPLICATION_EXPORT
+#elif defined(KDSINGLEAPPLICATION_SHARED_BUILD)
+#define KDSINGLEAPPLICATION_EXPORT Q_DECL_EXPORT
+#else
+#define KDSINGLEAPPLICATION_EXPORT Q_DECL_IMPORT
+#endif
+
+#endif // KDSINGLEAPPLICATION_LIB_H

3rdparty/kdsingleapplication/kdsingleapplication_localsocket.cpp

@@ -0,0 +1,304 @@
+/*
+    MIT License
+
+    Copyright (C) 2019-2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+*/
+
+#include "kdsingleapplication_localsocket_p.h"
+
+#include <QtCore/QDir>
+#include <QtCore/QDeadlineTimer>
+#include <QtCore/QTimer>
+#include <QtCore/QLockFile>
+#include <QtCore/QDataStream>
+
+#include <QtCore/QtDebug>
+#include <QtCore/QLoggingCategory>
+
+#include <QtNetwork/QLocalServer>
+#include <QtNetwork/QLocalSocket>
+
+#include <chrono>
+#include <algorithm>
+
+#if defined(Q_OS_UNIX)
+// for ::getuid()
+#include <sys/types.h>
+#include <unistd.h>
+#endif
+
+#if defined(Q_OS_WIN)
+#include <qt_windows.h>
+#endif
+
+static const auto LOCALSOCKET_CONNECTION_TIMEOUT = std::chrono::seconds(5);
+static const char LOCALSOCKET_PROTOCOL_VERSION = 2;
+
+Q_LOGGING_CATEGORY(kdsaLocalSocket, "kdsingleapplication.localsocket", QtWarningMsg);
+
+KDSingleApplicationLocalSocket::KDSingleApplicationLocalSocket(const QString &name, QObject *parent)
+    : QObject(parent)
+{
+#if defined(Q_OS_UNIX)
+    m_socketName = QStringLiteral("kdsingleapp-%1-%2-%3")
+            .arg(::getuid())
+            .arg(qEnvironmentVariable("XDG_SESSION_ID"), name);
+#elif defined(Q_OS_WIN)
+    // I'm not sure of a "global session identifier" on Windows; are
+    // multiple logins from the same user a possibility? For now, following this:
+    // https://docs.microsoft.com/en-us/windows/desktop/devnotes/getting-the-session-id-of-the-current-process
+
+    DWORD sessionId;
+    BOOL haveSessionId = ProcessIdToSessionId(GetCurrentProcessId(), &sessionId);
+
+    m_socketName = QString::fromUtf8("kdsingleapp-%1-%2")
+            .arg(haveSessionId ? sessionId : 0)
+            .arg(name);
+#else
+#error "KDSingleApplication has not been ported to this platform"
+#endif
+
+    const QString lockFilePath =
+            QDir::tempPath() + QLatin1Char('/') + m_socketName + QLatin1String(".lock");
+
+    qCDebug(kdsaLocalSocket) << "Socket name is" << m_socketName;
+    qCDebug(kdsaLocalSocket) << "Lock file path is" << lockFilePath;
+
+    std::unique_ptr<QLockFile> lockFile(new QLockFile(lockFilePath));
+    lockFile->setStaleLockTime(0);
+
+    if (!lockFile->tryLock()) {
+        // someone else has the lock => we're secondary
+        return;
+    }
+
+    std::unique_ptr<QLocalServer> server = std::make_unique<QLocalServer>();
+    if (!server->listen(m_socketName)) {
+        // maybe the primary crashed, leaving a stale socket; delete it and try again
+        QLocalServer::removeServer(m_socketName);
+        if (!server->listen(m_socketName)) {
+            // TODO: better error handling.
+            qWarning("KDSingleApplication: unable to make the primary instance listen on %ls: %ls",
+                     qUtf16Printable(m_socketName),
+                     qUtf16Printable(server->errorString()));
+
+            return;
+        }
+    }
+
+    connect(server.get(), &QLocalServer::newConnection,
+            this, &KDSingleApplicationLocalSocket::handleNewConnection);
+
+    m_lockFile = std::move(lockFile);
+    m_localServer = std::move(server);
+}
+
+KDSingleApplicationLocalSocket::~KDSingleApplicationLocalSocket() = default;
+
+bool KDSingleApplicationLocalSocket::isPrimaryInstance() const
+{
+    return m_localServer != nullptr;
+}
+
+bool KDSingleApplicationLocalSocket::sendMessage(const QByteArray &message, int timeout)
+{
+    Q_ASSERT(!isPrimaryInstance());
+    QLocalSocket socket;
+
+    qCDebug(kdsaLocalSocket) << "Preparing to send message" << message << "with timeout" << timeout;
+
+    QDeadlineTimer deadline(timeout);
+
+    // There is an inherent race here with the setup of the server side.
+    // Even if the socket lock is held by the server, the server may not
+    // be listening yet. So this connection may fail; keep retrying
+    // until we hit the timeout.
+    do {
+        socket.connectToServer(m_socketName);
+        if (socket.waitForConnected(deadline.remainingTime()))
+            break;
+    } while (!deadline.hasExpired());
+
+    qCDebug(kdsaLocalSocket) << "Socket state:" << socket.state() << "Timer remaining" << deadline.remainingTime() << "Expired?" << deadline.hasExpired();
+
+    if (deadline.hasExpired())
+        return false;
+
+    socket.write(&LOCALSOCKET_PROTOCOL_VERSION, 1);
+
+    {
+        QByteArray encodedMessage;
+        QDataStream ds(&encodedMessage, QIODevice::WriteOnly);
+        ds << message;
+        socket.write(encodedMessage);
+    }
+
+    qCDebug(kdsaLocalSocket) << "Wrote message in the socket" << "Timer remaining" << deadline.remainingTime() << "Expired?" << deadline.hasExpired();
+
+    // There is no acknowledgement mechanism here.
+    // Should there be one?
+
+    while (socket.bytesToWrite() > 0) {
+        if (!socket.waitForBytesWritten(deadline.remainingTime()))
+            return false;
+    }
+
+    qCDebug(kdsaLocalSocket) << "Bytes written, now disconnecting" << "Timer remaining" << deadline.remainingTime() << "Expired?" << deadline.hasExpired();
+
+    socket.disconnectFromServer();
+
+    if (socket.state() == QLocalSocket::UnconnectedState)
+        return true;
+
+    if (!socket.waitForDisconnected(deadline.remainingTime()))
+        return false;
+
+    qCDebug(kdsaLocalSocket) << "Disconnected -- success!";
+
+    return true;
+}
+
+void KDSingleApplicationLocalSocket::handleNewConnection()
+{
+    Q_ASSERT(m_localServer);
+
+    QLocalSocket *socket = m_localServer->nextPendingConnection();
+
+    qCDebug(kdsaLocalSocket) << "Got new connection on" << m_socketName << "state" << socket->state();
+
+    Connection c(socket);
+
+    c.readDataConnection = QObjectConnectionHolder(
+                connect(c.socket.get(), &QLocalSocket::readyRead,
+                        this, &KDSingleApplicationLocalSocket::readDataFromSecondary));
+
+    c.secondaryDisconnectedConnection = QObjectConnectionHolder(
+                connect(c.socket.get(), &QLocalSocket::disconnected,
+                        this, &KDSingleApplicationLocalSocket::secondaryDisconnected));
+
+    c.abortConnection = QObjectConnectionHolder(
+                connect(c.timeoutTimer.get(), &QTimer::timeout,
+                        this, &KDSingleApplicationLocalSocket::abortConnectionToSecondary));
+
+    m_clients.push_back(std::move(c));
+
+    // Note that by the time we get here, the socket could've already been closed,
+    // and no signals emitted (hello, Windows!). Read what's already in the socket.
+    if (readDataFromSecondarySocket(socket))
+        return;
+
+    if (socket->state() == QLocalSocket::UnconnectedState)
+        secondarySocketDisconnected(socket);
+}
+
+template <typename Container>
+static auto findConnectionBySocket(Container &container, QLocalSocket *socket)
+{
+    auto i = std::find_if(container.begin(),
+                          container.end(),
+                          [socket](const auto &c) { return c.socket.get() == socket; });
+    Q_ASSERT(i != container.end());
+    return i;
+}
+
+template <typename Container>
+static auto findConnectionByTimer(Container &container, QTimer *timer)
+{
+    auto i = std::find_if(container.begin(),
+                          container.end(),
+                          [timer](const auto &c) { return c.timeoutTimer.get() == timer; });
+    Q_ASSERT(i != container.end());
+    return i;
+}
+
+void KDSingleApplicationLocalSocket::readDataFromSecondary()
+{
+    QLocalSocket *socket = static_cast<QLocalSocket *>(sender());
+    readDataFromSecondarySocket(socket);
+}
+
+bool KDSingleApplicationLocalSocket::readDataFromSecondarySocket(QLocalSocket *socket)
+{
+    auto i = findConnectionBySocket(m_clients, socket);
+    Connection &c = *i;
+    c.readData.append(socket->readAll());
+
+    qCDebug(kdsaLocalSocket) << "Got more data from a secondary. Data read so far:" << c.readData;
+
+    const QByteArray &data = c.readData;
+
+    if (data.size() >= 1) {
+        if (data[0] != LOCALSOCKET_PROTOCOL_VERSION) {
+            qCDebug(kdsaLocalSocket) << "Got an invalid protocol version";
+            m_clients.erase(i);
+            return true;
+        }
+    }
+
+    QDataStream ds(data);
+    ds.skipRawData(1);
+
+    ds.startTransaction();
+    QByteArray message;
+    ds >> message;
+
+    if (ds.commitTransaction()) {
+        qCDebug(kdsaLocalSocket) << "Got a complete message:" << message;
+        Q_EMIT messageReceived(message);
+        m_clients.erase(i);
+        return true;
+    }
+
+    return false;
+}
+
+void KDSingleApplicationLocalSocket::secondaryDisconnected()
+{
+    QLocalSocket *socket = static_cast<QLocalSocket *>(sender());
+    secondarySocketDisconnected(socket);
+}
+
+void KDSingleApplicationLocalSocket::secondarySocketDisconnected(QLocalSocket *socket)
+{
+    auto i = findConnectionBySocket(m_clients, socket);
+    Connection c = std::move(*i);
+    m_clients.erase(i);
+
+    qCDebug(kdsaLocalSocket) << "Secondary disconnected. Data read:" << c.readData;
+}
+
+void KDSingleApplicationLocalSocket::abortConnectionToSecondary()
+{
+    QTimer *timer = static_cast<QTimer *>(sender());
+
+    auto i = findConnectionByTimer(m_clients, timer);
+    Connection c = std::move(*i);
+    m_clients.erase(i);
+
+    qCDebug(kdsaLocalSocket) << "Secondary timed out. Data read:" << c.readData;
+}
+
+KDSingleApplicationLocalSocket::Connection::Connection(QLocalSocket *socket)
+    : socket(socket)
+    , timeoutTimer(new QTimer)
+{
+    timeoutTimer->start(LOCALSOCKET_CONNECTION_TIMEOUT);
+}

3rdparty/kdsingleapplication/kdsingleapplication_localsocket_p.h

@@ -0,0 +1,133 @@
+/*
+    MIT License
+
+    Copyright (C) 2019-2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+*/
+
+#ifndef KDSINGLEAPPLICATION_LOCALSOCKET_P_H
+#define KDSINGLEAPPLICATION_LOCALSOCKET_P_H
+
+#include <QtCore/QObject>
+#include <QtCore/QByteArray>
+#include <QtCore/QString>
+
+QT_BEGIN_NAMESPACE
+class QLockFile;
+class QLocalServer;
+class QLocalSocket;
+class QTimer;
+QT_END_NAMESPACE
+
+#include <memory>
+#include <vector>
+
+struct QObjectDeleteLater
+{
+    void operator()(QObject *o) { o->deleteLater(); }
+};
+
+class QObjectConnectionHolder
+{
+    Q_DISABLE_COPY(QObjectConnectionHolder)
+    QMetaObject::Connection c;
+
+public:
+    QObjectConnectionHolder() {}
+
+    explicit QObjectConnectionHolder(QMetaObject::Connection c)
+        : c(std::move(c))
+    {
+    }
+
+    ~QObjectConnectionHolder()
+    {
+        QObject::disconnect(c);
+    }
+
+    QObjectConnectionHolder(QObjectConnectionHolder &&other) noexcept
+        : c(std::exchange(other.c, {}))
+    {}
+
+    QObjectConnectionHolder &operator=(QObjectConnectionHolder &&other) noexcept
+    {
+        QObjectConnectionHolder moved(std::move(other));
+        swap(moved);
+        return *this;
+    }
+
+    void swap(QObjectConnectionHolder &other) noexcept
+    {
+        using std::swap;
+        swap(c, other.c);
+    }
+};
+
+class KDSingleApplicationLocalSocket : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit KDSingleApplicationLocalSocket(const QString &name,
+                                            QObject *parent = nullptr);
+    ~KDSingleApplicationLocalSocket();
+
+    bool isPrimaryInstance() const;
+
+public Q_SLOTS:
+    bool sendMessage(const QByteArray &message, int timeout);
+
+Q_SIGNALS:
+    void messageReceived(const QByteArray &message);
+
+private:
+    void handleNewConnection();
+    void readDataFromSecondary();
+    bool readDataFromSecondarySocket(QLocalSocket *socket);
+    void secondaryDisconnected();
+    void secondarySocketDisconnected(QLocalSocket *socket);
+    void abortConnectionToSecondary();
+
+    QString m_socketName;
+
+    std::unique_ptr<QLockFile> m_lockFile; // protects m_localServer
+    std::unique_ptr<QLocalServer> m_localServer;
+
+    struct Connection {
+        explicit Connection(QLocalSocket *s);
+
+        std::unique_ptr<QLocalSocket, QObjectDeleteLater> socket;
+        std::unique_ptr<QTimer, QObjectDeleteLater> timeoutTimer;
+        QByteArray readData;
+
+        // socket/timeoutTimer are deleted via deleteLater (as we delete them
+        // in slots connected to their signals). Before the deleteLater is acted upon,
+        // they may emit further signals, triggering logic that it's not supposed
+        // to be triggered (as the Connection has already been destroyed).
+        // Use this Holder to break the connections.
+        QObjectConnectionHolder readDataConnection;
+        QObjectConnectionHolder secondaryDisconnectedConnection;
+        QObjectConnectionHolder abortConnection;
+    };
+
+    std::vector<Connection> m_clients;
+};
+
+#endif // KDSINGLEAPPLICATION_LOCALSOCKET_P_H

3rdparty/kdsingleapplication/src.pro

@@ -0,0 +1,20 @@
+include(../common.pri)
+
+TEMPLATE = lib
+TARGET = kdsingleapplication
+QT = core network
+CONFIG += static
+
+SOURCES += \
+    kdsingleapplication.cpp \
+    kdsingleapplication_localsocket.cpp \
+
+HEADERS += \
+    kdsingleapplication.h \
+    kdsingleapplication_lib.h \
+    kdsingleapplication_localsocket_p.h \
+
+DEFINES += \
+    KDSINGLEAPPLICATION_BUILD
+
+win32:LIBS += -lkernel32

CMakeLists.txt

@@ -321,7 +321,7 @@ if(ECM_FOUND)
     include(KDEInstallDirs)
 endif()
 
-find_package(KF5 QUIET COMPONENTS CoreAddons Crash DBusAddons)
+find_package(KF5 QUIET COMPONENTS CoreAddons Crash)
 set_package_properties(
     KF5::CoreAddons
     PROPERTIES
@@ -330,14 +330,6 @@ set_package_properties(
     URL "https://api.kde.org/frameworks/kcoreaddons/"
     PURPOSE "About Calamares"
 )
-set_package_properties(
-    KF5::DBusAddons
-    PROPERTIES
-    TYPE REQUIRED
-    DESCRIPTION "Classes for DBus activation"
-    URL "https://api.kde.org/frameworks/dbusaddons/"
-    PURPOSE "Unique instance of Calamares"
-)
 if(NOT KF5Crash_FOUND)
     if(BUILD_KF5Crash)
         message(WARNING "BUILD_KF5Crash is set, but KF5::Crash is not available.")
@@ -551,6 +543,7 @@ include(GNUInstallDirs)
 # libraries for Calamares.
 set(Calamares_LIBRARIES calamares)
 
+add_subdirectory(3rdparty/kdsingleapplication)
 add_subdirectory(src)
 
 add_feature_info(Python ${WITH_PYTHON} "Python job modules")

src/calamares/CMakeLists.txt

@@ -36,13 +36,9 @@ calamares_automoc( calamares_bin )
 calamares_autouic( calamares_bin )
 calamares_autorcc( calamares_bin )
 
-if(kdsagSources)
-    set_source_files_properties(${kdsagSources} PROPERTIES AUTOMOC OFF)
-endif()
-
 target_link_libraries(
     calamares_bin
-    PRIVATE calamares calamaresui calamares-i18n Qt5::Core Qt5::Widgets KF5::CoreAddons KF5::DBusAddons
+    PRIVATE calamares calamaresui calamares-i18n kdsingleapplication Qt5::Core Qt5::Widgets KF5::CoreAddons
 )
 if(BUILD_KF5Crash)
     target_link_libraries(calamares_bin PRIVATE KF5::Crash)

src/calamares/main.cpp

@@ -16,8 +16,10 @@
 #include "utils/Logger.h"
 #include "utils/Retranslator.h"
 
+// From 3rdparty/
+#include "kdsingleapplication.h"
+
 #include <KCoreAddons/KAboutData>
-#include <KDBusAddons/KDBusService>
 #ifdef BUILD_KF5Crash
 #include <KCrash/KCrash>
 #endif
@@ -26,6 +28,8 @@
 #include <QDebug>
 #include <QDir>
 
+#include <memory>
+
 /** @brief Gets debug-level from -D command-line-option
  *
  * If unset, use LOGERROR (corresponding to -D1), although
@@ -124,9 +128,17 @@ main( int argc, char* argv[] )
     KCrash::setFlags( KCrash::SaferDialog | KCrash::AlwaysDirectly );
 #endif
 
-    bool is_debug = handle_args( a );
-
-    KDBusService service( is_debug ? KDBusService::Multiple : KDBusService::Unique );
+    std::unique_ptr< KDSingleApplication > possiblyUnique;
+    const bool is_debug = handle_args( a );
+    if ( !is_debug )
+    {
+        possiblyUnique = std::make_unique< KDSingleApplication >();
+        if ( !possiblyUnique->isPrimaryInstance() )
+        {
+            qCritical() << "Calamares is already running.";
+            return 87;  // EUSERS on Linux
+        }
+    }
 
     Calamares::Settings::init( is_debug );
     if ( !Calamares::Settings::instance() || !Calamares::Settings::instance()->isValid() )