FEAT(client): Allow specifying config file via commandline switch

This adds the switch -c/--config to the mumble client. If -c is
followed by a filename, this file will be read instead of the
standard config. A new config option database= has been added to
the 'General' section of the ini file. This can be used to specify
a different database which is necessary to run multiple completely
separate Mumble instances at the same time.

Additionaly the (undocumented) function to merge another ini file
by providing it as a parameter has been removed as it was
conflicting with the added functionality.

FIXES #3953

src/mumble/Database.cpp

@@ -40,11 +40,10 @@ static bool execQueryAndLogFailure(QSqlQuery &query, const QString &queryString)
 }
 
 
-Database::Database(const QString &dbname) {
-	db = QSqlDatabase::addDatabase(QLatin1String("QSQLITE"), dbname);
+bool Database::findOrCreateDatabase()
+{
 	QSettings qs;
 	QStringList datapaths;
-	int i;
 
 	datapaths << g.qdBasePath.absolutePath();
 	datapaths << QStandardPaths::writableLocation(QStandardPaths::DataLocation);
@@ -55,42 +54,65 @@ Database::Database(const QString &dbname) {
 	datapaths << QDir::currentPath();
 	datapaths << qApp->applicationDirPath();
 	datapaths << qs.value(QLatin1String("InstPath")).toString();
-	bool found = false;
+	datapaths.removeAll(QLatin1String(""));
+	datapaths.removeDuplicates();
 
-	for (i = 0; (i < datapaths.size()) && ! found; i++) {
-		if (!datapaths[i].isEmpty()) {
-			// Try the legacy path first, and use it if it exists.
-			// If it doesn't, use the new, non-hidden version.
-			QFile legacyDatabaseFile(datapaths[i] + QLatin1String("/.mumble.sqlite"));
-			if (legacyDatabaseFile.exists()) {
-				db.setDatabaseName(legacyDatabaseFile.fileName());
-				found = db.open();
+	// Try to find an existing database
+	foreach(const QString &datapath, datapaths) {
+		// Try the legacy path first, and use it if it exists.
+		// If it doesn't, use the new, non-hidden version.
+		QFile legacyDatabaseFile(datapath + QLatin1String("/.mumble.sqlite"));
+		if (legacyDatabaseFile.exists()) {
+			db.setDatabaseName(legacyDatabaseFile.fileName());
+			if (db.open()) {
+				return true;
 			}
-			if (found) {
-				break;
-			}
-			QFile databaseFile(datapaths[i] + QLatin1String("/mumble.sqlite"));
-			if (databaseFile.exists()) {
-				db.setDatabaseName(databaseFile.fileName());
-				found = db.open();
+		}
+		QFile databaseFile(datapath + QLatin1String("/mumble.sqlite"));
+		if (databaseFile.exists()) {
+			db.setDatabaseName(databaseFile.fileName());
+			if (db.open()) {
+				return true;
 			}
 		}
 	}
 
-	if (! found) {
-		for (i = 0; (i < datapaths.size()) && ! found; i++) {
-			if (!datapaths[i].isEmpty()) {
-				QDir::root().mkpath(datapaths[i]);
-				QFile f(datapaths[i] + QLatin1String("/mumble.sqlite"));
-				db.setDatabaseName(f.fileName());
-				found = db.open();
+	// There is no existing database, so we create one
+	foreach(const QString &datapath, datapaths) {
+		QDir::root().mkpath(datapath);
+		QFile f(datapath + QLatin1String("/mumble.sqlite"));
+		db.setDatabaseName(f.fileName());
+		if (db.open()) {
+			return true;
+		}
+	}
+	return false;
+}
+
+Database::Database(const QString &dbname) {
+	db = QSqlDatabase::addDatabase(QLatin1String("QSQLITE"), dbname);
+	if (!g.s.qsDatabaseLocation.isEmpty()) {
+		QFile configuredLocation(g.s.qsDatabaseLocation);
+		if (configuredLocation.exists()) {
+			db.setDatabaseName(g.s.qsDatabaseLocation);
+			db.open();
+		} else {
+			int result = QMessageBox::critical(nullptr, QLatin1String("Mumble"), tr("The database file '%1' set in the configuration file does not exist. Do you want to create a new database file at this location?").arg(g.s.qsDatabaseLocation), QMessageBox::Yes | QMessageBox::No);
+			if (result == QMessageBox::Yes) {
+				db.setDatabaseName(g.s.qsDatabaseLocation);
+				db.open();
+			} else {
+				qFatal("Database: File not found");
 			}
 		}
 	}
-
-	if (! found) {
-		QMessageBox::critical(nullptr, QLatin1String("Mumble"), tr("Mumble failed to initialize a database in any\nof the possible locations."), QMessageBox::Ok | QMessageBox::Default, QMessageBox::NoButton);
-		qFatal("Database: Failed initialization");
+	if (!db.isOpen()) {
+		if (findOrCreateDatabase()) {
+			g.s.qsDatabaseLocation = db.databaseName();
+		} else {
+			QMessageBox::critical(nullptr, QLatin1String("Mumble"), tr("Mumble failed to initialize a database in any of the possible locations."), QMessageBox::Ok | QMessageBox::Default, QMessageBox::NoButton);
+			qFatal("Database: Failed initialization");
+		}
 	}
 
 	QFileInfo fi(db.databaseName());

src/mumble/Database.h

@@ -25,6 +25,10 @@ class Database : public QObject {
 		Q_DISABLE_COPY(Database)
 
 		QSqlDatabase db;
+		/// This function is called when no database location is configured
+		/// in the config file. It tries to find an existing database file and
+		/// creates a new one if none was found.
+		bool findOrCreateDatabase();
 	public:
 		Database(const QString &dbname);
 		~Database() Q_DECL_OVERRIDE;

src/mumble/Global.cpp

@@ -65,7 +65,7 @@ static void migrateDataDir() {
 }
 #endif // Q_OS_WIN
 
-Global::Global() {
+Global::Global(const QString &qsConfigPath) {
 	mw = 0;
 	db = 0;
 	p = 0;
@@ -119,29 +119,37 @@ Global::Global() {
 	bDebugDumpInput = false;
 	bDebugPrintQueue = false;
 
-	QStringList qsl;
-	qsl << QCoreApplication::instance()->applicationDirPath();
-	qsl << QStandardPaths::writableLocation(QStandardPaths::DataLocation);
-
 #if defined(Q_OS_WIN)
 	QString appdata;
 	wchar_t appData[MAX_PATH];
-	if (SUCCEEDED(SHGetFolderPath(nullptr, CSIDL_APPDATA, nullptr, SHGFP_TYPE_CURRENT, appData))) {
-		appdata = QDir::fromNativeSeparators(QString::fromWCharArray(appData));
-
-		if (!appdata.isEmpty()) {
-			appdata.append(QLatin1String("/Mumble"));
-			qsl << appdata;
-		}
-	}
 #endif
 
-	foreach(const QString &dir, qsl) {
-		QFile inifile(QString::fromLatin1("%1/mumble.ini").arg(dir));
-		if (inifile.exists() && inifile.permissions().testFlag(QFile::WriteUser)) {
-			qdBasePath.setPath(dir);
-			qs = new QSettings(inifile.fileName(), QSettings::IniFormat);
-			break;
+	if (!qsConfigPath.isEmpty()) {
+		QFile inifile(qsConfigPath);
+		qs = new QSettings(inifile.fileName(), QSettings::IniFormat);
+	} else {
+		QStringList qsl;
+		qsl << QCoreApplication::instance()->applicationDirPath();
+		qsl << QStandardPaths::writableLocation(QStandardPaths::DataLocation);
+
+#if defined(Q_OS_WIN)
+		if (SUCCEEDED(SHGetFolderPath(nullptr, CSIDL_APPDATA, nullptr, SHGFP_TYPE_CURRENT, appData))) {
+			appdata = QDir::fromNativeSeparators(QString::fromWCharArray(appData));
+
+			if (!appdata.isEmpty()) {
+				appdata.append(QLatin1String("/Mumble"));
+				qsl << appdata;
+			}
+		}
+#endif
+
+		foreach(const QString &dir, qsl) {
+			QFile inifile(QString::fromLatin1("%1/mumble.ini").arg(dir));
+			if (inifile.exists() && inifile.permissions().testFlag(QFile::WriteUser)) {
+				qdBasePath.setPath(dir);
+				qs = new QSettings(inifile.fileName(), QSettings::IniFormat);
+				break;
+			}
 		}
 	}
 

src/mumble/Global.h

@@ -108,7 +108,7 @@ public:
 	bool bHappyEaster;
 	static const char ccHappyEaster[];
 
-	Global();
+	Global(const QString &qsConfigPath = QString());
 	~Global();
 };
 

src/mumble/Settings.cpp

@@ -674,6 +674,8 @@ void Settings::load(QSettings* settings_ptr) {
 	// Config updates
 	SAVELOAD(uiUpdateCounter, "lastupdate");
 
+	SAVELOAD(qsDatabaseLocation, "databaselocation");
+
 	SAVELOAD(bMute, "audio/mute");
 	SAVELOAD(bDeaf, "audio/deaf");
 	LOADENUM(atTransmit, "audio/transmit");
@@ -1031,6 +1033,8 @@ void Settings::save() {
 	// Config updates
 	SAVELOAD(uiUpdateCounter, "lastupdate");
 
+	SAVELOAD(qsDatabaseLocation, "databaselocation");
+
 	SAVELOAD(bMute, "audio/mute");
 	SAVELOAD(bDeaf, "audio/deaf");
 	SAVELOAD(atTransmit, "audio/transmit");

src/mumble/Settings.h

@@ -430,6 +430,9 @@ struct Settings {
 	// Config updates
 	unsigned int uiUpdateCounter;
 
+	/// Path to SQLite-DB
+	QString qsDatabaseLocation;
+
 	// Nonsaved
 	LoopMode lmLoopMode;
 	float dPacketLoss;

src/mumble/main.cpp

@@ -125,7 +125,26 @@ int main(int argc, char **argv) {
 	}
 #endif
 
-	Global::g_global_struct = new Global();
+	// This argument has to be parsed first, since it's value is needed to create the global struct,
+	// which other switches are modifying. If it is parsed first, the order of the arguments does not matter.
+	QStringList args = a.arguments();
+	const int index = std::max(args.lastIndexOf(QLatin1String("-c")), args.lastIndexOf(QLatin1String("--config")));
+	if (index >= 0) {
+		if (index + 1 < args.count()) {
+			QFile inifile(args.at(index + 1));
+			if (inifile.exists() && inifile.permissions().testFlag(QFile::WriteUser)) {
+				Global::g_global_struct = new Global(args.at(index + 1));
+			} else {
+				printf("%s", qPrintable(MainWindow::tr("Configuration file %1 does not exist or is not writable.\n").arg(args.at(index + 1))));
+				return 1;
+			}
+		} else {
+			qCritical("Missing argument for --config!");
+			return 1;
+		}
+	} else {
+		Global::g_global_struct = new Global();
+	}
 
 #if QT_VERSION < QT_VERSION_CHECK(5,10,0)
 	// For Qt >= 5.10 we use QRandomNumberGenerator that is seeded automatically
@@ -143,8 +162,8 @@ int main(int argc, char **argv) {
 	bool bRpcMode = false;
 	QString rpcCommand;
 	QUrl url;
+
 	if (a.arguments().count() > 1) {
-		QStringList args = a.arguments();
 		for (int i = 1; i < args.count(); ++i) {
 			if (args.at(i) == QLatin1String("-h") || args.at(i) == QLatin1String("--help")
 #if defined(Q_OS_WIN)
@@ -165,6 +184,10 @@ int main(int argc, char **argv) {
 					"  -h, --help    Show this help text and exit.\n"
 					"  -m, --multiple\n"
 					"                Allow multiple instances of the client to be started.\n"
+					"  -c, --config\n"
+					"                Specify an alternative configuration file.\n"
+					"                If you use this to run multiple instances of Mumble at once,\n"
+					"                make sure to set an alternative 'database' value in the config.\n"
 					"  -n, --noidentity\n"
 					"                Suppress loading of identity files (i.e., certificates.)\n"
 					"  -jn, --jackname <arg>\n"