Cleanup config initialization, add local config options

* Fix #5313, allow specifying local config path using environment variable and command line flag
* Add command line flag `--localconfig <path>` to specify a file path to use for the local configuration settings.
* Add environment variable support to set config files paths: `KPXC_CONFIG` and `KPXC_CONFIG_LOCAL` to override default locations.
* Reorder startup sequence to load specified config files earlier to allow for theme settings and other early options to be picked up.
* Removed old command line option `--pw`, no longer used.

* Attempt a fix of application not closing when last window is gone. Only set `QApplication::setQuitOnLastWindowClosed(true)` when tray icon is enabled instead of always.

docs/styles/dark.css

@@ -455,6 +455,7 @@ p{font-family: "Noto Sans",sans-serif !important}
 blockquote{color:var(--quotecolor) !important}
 .quoteblock{color:var(--textcolor)}
 code{color:var(--textcoloralt);background-color: var(--sidebarbackground) !important}
+pre,pre>code{line-height:1.25; color:var(--textcoloralt);}
 .keyseq{color:var(--textcoloralt);}
 
 

docs/topics/DownloadInstall.adoc

@@ -51,6 +51,8 @@ image::linux_store.png[]
 
 The Snap and Flatpak options are sandboxed applications (more secure). The Native option is installed with the operating system files. Read more about the limitations of these options here: https://keepassxc.org/docs/#faq-appsnap-yubikey[KeePassXC Snap FAQ]
 
+NOTE: KeePassXC stores a configuration file in `~/.cache` to remember window position, recent files, and other local settings. If you mount this folder to a tmpdisk you will lose settings after reboot.
+
 === macOS
 To install the KeePassXC app on macOS, double click on the downloaded DMG file and use the click and drag option as shown:
 

docs/topics/UserInterface.adoc

@@ -48,4 +48,41 @@ image::compact_mode_comparison.png[]
 
 === Keyboard Shortcuts
 include::KeyboardShortcuts.adoc[tag=content, leveloffset=+1]
+
+// tag::advanced[]
+=== Command-Line Options
+You can use the following command line options to tailor the application to your preferences:
+
+----
+Usage: keepassxc.exe [options] [filename(s)]
+KeePassXC - cross-platform password manager
+
+Options:
+  -?, -h, --help               Displays help on commandline options.
+  --help-all                   Displays help including Qt specific options.
+  -v, --version                Displays version information.
+  --config <config>            path to a custom config file
+  --localconfig <localconfig>  path to a custom local config file
+  --keyfile <keyfile>          key file of the database
+  --pw-stdin                   read password of the database from stdin
+  --debug-info                 Displays debugging information.
+
+Arguments:
+  filename(s)                  filenames of the password databases to open (*.kdbx)
+----
+
+Additionally, the following environment variables may be useful when running the application:
+
+[grid=rows, frame=none, width=75%]
+|===
+|Env Var                        | Description
+
+|KPXC_CONFIG                    | Override default path to roaming configuration file
+|KPXC_CONFIG_LOCAL              | Override default path to local configuration file
+|SSH_AUTH_SOCKET                | Path of the unix file socket that the agent uses for communication with other processes (SSH Agent)
+|QT_SCALE_FACTOR [numeric]      | Defines a global scale factor for the whole application, including point-sized fonts.
+|QT_SCREEN_SCALE_FACTORS [list] | Specifies scale factors for each screen. See https://doc.qt.io/qt-5/highdpi.html#high-dpi-support-in-qt
+|QT_SCALE_FACTOR_ROUNDING_POLICY | Control device pixel ratio rounding to the nearest integer. See https://doc.qt.io/qt-5/highdpi.html#high-dpi-support-in-qt
+|===
+// end::advanced[]
 // end::content[]

src/core/Config.cpp

@@ -22,6 +22,7 @@
 #include <QCoreApplication>
 #include <QDir>
 #include <QHash>
+#include <QProcessEnvironment>
 #include <QSettings>
 #include <QSize>
 #include <QStandardPaths>
@@ -418,49 +419,17 @@ void Config::migrate()
     sync();
 }
 
-Config::Config(const QString& fileName, QObject* parent)
+Config::Config(const QString& configFileName, const QString& localConfigFileName, QObject* parent)
     : QObject(parent)
 {
-    init(fileName);
+    init(configFileName, localConfigFileName);
 }
 
 Config::Config(QObject* parent)
     : QObject(parent)
 {
-    // Check if we are running in portable mode, if so store the config files local to the app
+    auto configFiles = defaultConfigFiles();
-    auto portablePath = QCoreApplication::applicationDirPath().append("/%1");
+    init(configFiles.first, configFiles.second);
-    if (QFile::exists(portablePath.arg(".portable"))) {
-        init(portablePath.arg("config/keepassxc.ini"), portablePath.arg("config/keepassxc_local.ini"));
-        return;
-    }
-
-    QString configPath;
-    QString localConfigPath;
-
-#if defined(Q_OS_WIN)
-    configPath = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
-    localConfigPath = QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation);
-#elif defined(Q_OS_MACOS)
-    configPath = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
-    localConfigPath = QStandardPaths::writableLocation(QStandardPaths::CacheLocation);
-#else
-    // On case-sensitive Operating Systems, force use of lowercase app directories
-    configPath = QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation) + "/keepassxc";
-    localConfigPath = QStandardPaths::writableLocation(QStandardPaths::GenericCacheLocation) + "/keepassxc";
-#endif
-
-    configPath += "/keepassxc";
-    localConfigPath += "/keepassxc";
-
-#ifdef QT_DEBUG
-    configPath += "_debug";
-    localConfigPath += "_debug";
-#endif
-
-    configPath += ".ini";
-    localConfigPath += ".ini";
-
-    init(QDir::toNativeSeparators(configPath), QDir::toNativeSeparators(localConfigPath));
 }
 
 Config::~Config()
@@ -488,6 +457,45 @@ void Config::init(const QString& configFileName, const QString& localConfigFileN
     connect(qApp, &QCoreApplication::aboutToQuit, this, &Config::sync);
 }
 
+QPair<QString, QString> Config::defaultConfigFiles()
+{
+    // Check if we are running in portable mode, if so store the config files local to the app
+    auto portablePath = QCoreApplication::applicationDirPath().append("/%1");
+    if (QFile::exists(portablePath.arg(".portable"))) {
+        return {portablePath.arg("config/keepassxc.ini"), portablePath.arg("config/keepassxc_local.ini")};
+    }
+
+    QString configPath;
+    QString localConfigPath;
+
+#if defined(Q_OS_WIN)
+    configPath = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
+    localConfigPath = QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation);
+#elif defined(Q_OS_MACOS)
+    configPath = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
+    localConfigPath = QStandardPaths::writableLocation(QStandardPaths::CacheLocation);
+#else
+    // On case-sensitive Operating Systems, force use of lowercase app directories
+    configPath = QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation) + "/keepassxc";
+    localConfigPath = QStandardPaths::writableLocation(QStandardPaths::GenericCacheLocation) + "/keepassxc";
+#endif
+
+    QString suffix;
+#ifdef QT_DEBUG
+    suffix = "_debug";
+#endif
+
+    configPath += QString("/keepassxc%1.ini").arg(suffix);
+    localConfigPath += QString("/keepassxc%1.ini").arg(suffix);
+
+    // Allow overriding the default location with env vars
+    const auto& env = QProcessEnvironment::systemEnvironment();
+    configPath = env.value("KPXC_CONFIG", configPath);
+    localConfigPath = env.value("KPXC_CONFIG_LOCAL", localConfigPath);
+
+    return {QDir::toNativeSeparators(configPath), QDir::toNativeSeparators(localConfigPath)};
+}
+
 Config* Config::instance()
 {
     if (!m_instance) {
@@ -497,12 +505,16 @@ Config* Config::instance()
     return m_instance;
 }
 
-void Config::createConfigFromFile(const QString& file)
+void Config::createConfigFromFile(const QString& configFileName, const QString& localConfigFileName)
 {
     if (m_instance) {
         delete m_instance;
     }
-    m_instance = new Config(file, qApp);
+
+    auto defaultFiles = defaultConfigFiles();
+    m_instance = new Config(configFileName.isEmpty() ? defaultFiles.first : configFileName,
+                            localConfigFileName.isEmpty() ? defaultFiles.second : localConfigFileName,
+                            qApp);
 }
 
 void Config::createTempFileInstance()
@@ -514,7 +526,7 @@ void Config::createTempFileInstance()
     bool openResult = tmpFile->open();
     Q_ASSERT(openResult);
     Q_UNUSED(openResult);
-    m_instance = new Config(tmpFile->fileName(), qApp);
+    m_instance = new Config(tmpFile->fileName(), "", qApp);
     tmpFile->setParent(m_instance);
 }
 

src/core/Config.h

@@ -198,17 +198,18 @@ public:
     void resetToDefaults();
 
     static Config* instance();
-    static void createConfigFromFile(const QString& file);
+    static void createConfigFromFile(const QString& configFileName, const QString& localConfigFileName = {});
     static void createTempFileInstance();
 
 signals:
     void changed(ConfigKey key);
 
 private:
-    Config(const QString& fileName, QObject* parent = nullptr);
+    Config(const QString& configFileName, const QString& localConfigFileName, QObject* parent);
     explicit Config(QObject* parent);
-    void init(const QString& configFileName, const QString& localConfigFileName = "");
+    void init(const QString& configFileName, const QString& localConfigFileName);
     void migrate();
+    static QPair<QString, QString> defaultConfigFiles();
 
     static QPointer<Config> m_instance;
 

src/gui/MainWindow.cpp

@@ -1269,6 +1269,8 @@ bool MainWindow::saveLastDatabases()
 void MainWindow::updateTrayIcon()
 {
     if (isTrayIconEnabled()) {
+        QApplication::setQuitOnLastWindowClosed(false);
+
         if (!m_trayIcon) {
             m_trayIcon = new QSystemTrayIcon(this);
             auto* menu = new QMenu(this);
@@ -1307,6 +1309,8 @@ void MainWindow::updateTrayIcon()
             m_trayIcon->setIcon(resources()->trayIconLocked());
         }
     } else {
+        QApplication::setQuitOnLastWindowClosed(true);
+
         if (m_trayIcon) {
             m_trayIcon->hide();
             delete m_trayIcon;

src/main.cpp

@@ -56,51 +56,47 @@ int main(int argc, char** argv)
     QGuiApplication::setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
 #endif
 
-    Application app(argc, argv);
-    Application::setApplicationName("KeePassXC");
-    Application::setApplicationVersion(KEEPASSXC_VERSION);
-    app.setProperty("KPXC_QUALIFIED_APPNAME", "org.keepassxc.KeePassXC");
-    app.applyTheme();
-#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
-    QGuiApplication::setDesktopFileName(app.property("KPXC_QUALIFIED_APPNAME").toString() + QStringLiteral(".desktop"));
-#endif
-
-    // don't set organizationName as that changes the return value of
-    // QStandardPaths::writableLocation(QDesktopServices::DataLocation)
-    Bootstrap::bootstrapApplication();
-
     QCommandLineParser parser;
     parser.setApplicationDescription(QObject::tr("KeePassXC - cross-platform password manager"));
     parser.addPositionalArgument(
-        "filename", QObject::tr("filenames of the password databases to open (*.kdbx)"), "[filename(s)]");
+        "filename(s)", QObject::tr("filenames of the password databases to open (*.kdbx)"), "[filename(s)]");
 
     QCommandLineOption configOption("config", QObject::tr("path to a custom config file"), "config");
+    QCommandLineOption localConfigOption(
+        "localconfig", QObject::tr("path to a custom local config file"), "localconfig");
     QCommandLineOption keyfileOption("keyfile", QObject::tr("key file of the database"), "keyfile");
     QCommandLineOption pwstdinOption("pw-stdin", QObject::tr("read password of the database from stdin"));
-    // This is needed under Windows where clients send --parent-window parameter with Native Messaging connect method
-    QCommandLineOption parentWindowOption(QStringList() << "pw"
-                                                        << "parent-window",
-                                          QObject::tr("Parent window handle"),
-                                          "handle");
 
     QCommandLineOption helpOption = parser.addHelpOption();
     QCommandLineOption versionOption = parser.addVersionOption();
     QCommandLineOption debugInfoOption(QStringList() << "debug-info", QObject::tr("Displays debugging information."));
     parser.addOption(configOption);
+    parser.addOption(localConfigOption);
     parser.addOption(keyfileOption);
     parser.addOption(pwstdinOption);
-    parser.addOption(parentWindowOption);
     parser.addOption(debugInfoOption);
 
+    Application app(argc, argv);
+    // don't set organizationName as that changes the return value of
+    // QStandardPaths::writableLocation(QDesktopServices::DataLocation)
+    Application::setApplicationName("KeePassXC");
+    Application::setApplicationVersion(KEEPASSXC_VERSION);
+    app.setProperty("KPXC_QUALIFIED_APPNAME", "org.keepassxc.KeePassXC");
+
     parser.process(app);
 
-    // Don't try and do anything with the application if we're only showing the help / version
+    // Exit early if we're only showing the help / version
     if (parser.isSet(versionOption) || parser.isSet(helpOption)) {
         return EXIT_SUCCESS;
     }
 
-    const QStringList fileNames = parser.positionalArguments();
+    // Process config file options early
+    if (parser.isSet(configOption) || parser.isSet(localConfigOption)) {
+        Config::createConfigFromFile(parser.value(configOption), parser.value(localConfigOption));
+    }
 
+    // Process single instance and early exit if already running
+    const QStringList fileNames = parser.positionalArguments();
     if (app.isAlreadyRunning()) {
         if (!fileNames.isEmpty()) {
             app.sendFileNamesToRunningInstance(fileNames);
@@ -109,7 +105,14 @@ int main(int argc, char** argv)
         return EXIT_SUCCESS;
     }
 
-    QApplication::setQuitOnLastWindowClosed(false);
+    // Apply the configured theme before creating any GUI elements
+    app.applyTheme();
+
+#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
+    QGuiApplication::setDesktopFileName(app.property("KPXC_QUALIFIED_APPNAME").toString() + QStringLiteral(".desktop"));
+#endif
+
+    Bootstrap::bootstrapApplication();
 
     if (!Crypto::init()) {
         QString error = QObject::tr("Fatal error while testing the cryptographic functions.");
@@ -128,10 +131,6 @@ int main(int argc, char** argv)
         return EXIT_SUCCESS;
     }
 
-    if (parser.isSet(configOption)) {
-        Config::createConfigFromFile(parser.value(configOption));
-    }
-
     MainWindow mainWindow;
     QObject::connect(&app, SIGNAL(anotherInstanceStarted()), &mainWindow, SLOT(bringToFront()));
     QObject::connect(&app, SIGNAL(applicationActivated()), &mainWindow, SLOT(bringToFront()));