diff --git a/declarative/declarativessudeviceinfo.cpp b/declarative/declarativessudeviceinfo.cpp
index 23c49f5..1c61fb3 100644
--- a/declarative/declarativessudeviceinfo.cpp
+++ b/declarative/declarativessudeviceinfo.cpp
@@ -26,7 +26,7 @@ QString DeclarativeSsuDeviceInfo::deviceModel()
     return info.deviceModel();
 }
 
-QString DeclarativeSsuDeviceInfo::displayName(const int type)
+QString DeclarativeSsuDeviceInfo::displayName(int type)
 {
     return info.displayName(type);
 }
diff --git a/declarative/declarativessudeviceinfo.h b/declarative/declarativessudeviceinfo.h
index 631f5e4..ed2e776 100644
--- a/declarative/declarativessudeviceinfo.h
+++ b/declarative/declarativessudeviceinfo.h
@@ -32,16 +32,19 @@ class DeclarativeSsuDeviceInfo : public QObject
      * multithreaded environment, unless you like funny results.
      */
     Q_INVOKABLE QString deviceFamily();
+
     /**
      * Try to find the device variant for the system this is running on.
      * If the device is not a variant it will return an empty string. If
      * fallback is set to true it return the device model in this case.
      */
     Q_INVOKABLE QString deviceVariant(bool fallback = false);
+
     /**
      * Try to find out ond what kind of system this is running
      */
     Q_INVOKABLE QString deviceModel();
+
     /**
      * Return a string suitable for display in dialogs, ...
      *
@@ -52,7 +55,7 @@ class DeclarativeSsuDeviceInfo : public QObject
      * If no manufacturer is found UNKNOWN is returned.
      * For an invalid type an empty string is returned.
      */
-    Q_INVOKABLE QString displayName(const int type);
+    Q_INVOKABLE QString displayName(int type);
 
 private:
     SsuDeviceInfo info;
diff --git a/libssu/sandbox.cpp b/libssu/sandbox.cpp
index 75e86a1..8e5a0c9 100644
--- a/libssu/sandbox.cpp
+++ b/libssu/sandbox.cpp
@@ -79,7 +79,7 @@ Sandbox::~Sandbox()
     }
 
     if (!m_tempDir.isEmpty() && QFileInfo(m_tempDir).exists()) {
-        if (QProcess::execute("rm", QStringList() << "-rf" << m_tempDir) != 0) {
+        if (!QDir(m_tempDir).removeRecursively()) {
             qWarning("%s: Failed to remove temporary directory", Q_FUNC_INFO);
         }
     }
@@ -276,7 +276,7 @@ bool Sandbox::prepare()
 
 QString Sandbox::createTmpDir(const QString &nameTemplate)
 {
-    static const int REASONABLE_REPEAT_COUNT = 10;
+    const int REASONABLE_REPEAT_COUNT = 10;
 
     for (int i = 0; i < REASONABLE_REPEAT_COUNT; ++i) {
         QString path;
diff --git a/libssu/ssu.cpp b/libssu/ssu.cpp
index 82975ef..80c65a3 100644
--- a/libssu/ssu.cpp
+++ b/libssu/ssu.cpp
@@ -37,7 +37,8 @@ static void restoreUid()
     }
 }
 
-Ssu::Ssu(): QObject()
+Ssu::Ssu()
+    : QObject()
 {
     errorFlag = false;
     pendingRequests = 0;
@@ -75,13 +76,13 @@ Ssu::Ssu(): QObject()
 
 // FIXME, the whole credentials stuff needs reworking
 // should probably be part of repo handling instead of core configuration
-QPair<QString, QString> Ssu::credentials(QString scope)
+QPair<QString, QString> Ssu::credentials(const QString &scope)
 {
     SsuCoreConfig *settings = SsuCoreConfig::instance();
     return settings->credentials(scope);
 }
 
-QString Ssu::credentialsScope(QString repoName, bool rndRepo)
+QString Ssu::credentialsScope(const QString &repoName, bool rndRepo)
 {
     SsuCoreConfig *settings = SsuCoreConfig::instance();
     SsuSettings repoSettings(SSU_REPO_CONFIGURATION, QSettings::IniFormat);
@@ -124,7 +125,7 @@ QString Ssu::credentialsScope(QString repoName, bool rndRepo)
     return settings->credentialsScope(repoName, rndRepo);
 }
 
-QString Ssu::credentialsUrl(QString scope)
+QString Ssu::credentialsUrl(const QString &scope)
 {
     SsuCoreConfig *settings = SsuCoreConfig::instance();
     return settings->credentialsUrl(scope);
@@ -178,19 +179,19 @@ void Ssu::setDeviceMode(Ssu::DeviceModeFlags mode, enum Ssu::EditMode editMode)
     settings->setDeviceMode(mode, editMode);
 }
 
-void Ssu::setFlavour(QString flavour)
+void Ssu::setFlavour(const QString &flavour)
 {
     SsuCoreConfig *settings = SsuCoreConfig::instance();
     settings->setFlavour(flavour);
 }
 
-void Ssu::setRelease(QString release, bool rnd)
+void Ssu::setRelease(const QString &release, bool rnd)
 {
     SsuCoreConfig *settings = SsuCoreConfig::instance();
     settings->setRelease(release, rnd);
 }
 
-void Ssu::setDomain(QString domain)
+void Ssu::setDomain(const QString &domain)
 {
     SsuCoreConfig *settings = SsuCoreConfig::instance();
     settings->setDomain(domain);
@@ -223,8 +224,9 @@ bool Ssu::registerDevice(QDomDocument *response)
         settings->setValue("registered", false);
         setError("Certificate is invalid");
         return false;
-    } else
+    } else {
         settings->setValue("certificate", certificate.toPem());
+    }
 
     QString privateKeyString = response->elementsByTagName("privateKey").at(0).toElement().text();
     QSslKey privateKey(privateKeyString.toLatin1(), QSsl::Rsa);
@@ -233,8 +235,9 @@ bool Ssu::registerDevice(QDomDocument *response)
         settings->setValue("registered", false);
         setError("Private key is invalid");
         return false;
-    } else
+    } else {
         settings->setValue("privateKey", privateKey.toPem());
+    }
 
     // oldUser is just for reference purposes, in case we want to notify
     // about owner changes for the device
@@ -256,7 +259,7 @@ bool Ssu::registerDevice(QDomDocument *response)
 
 // RND repos have flavour (devel, testing, release), and release (latest, next)
 // Release repos only have release (latest, next, version number)
-QString Ssu::repoUrl(QString repoName, bool rndRepo,
+QString Ssu::repoUrl(const QString &repoName, bool rndRepo,
                      QHash<QString, QString> repoParameters,
                      QHash<QString, QString> parametersOverride)
 {
@@ -289,7 +292,7 @@ void Ssu::requestFinished(QNetworkReply *reply)
 
     /// @TODO: indicate that the device is not registered if there's a 404 on credentials update url
     if (settings->contains("home-url")) {
-        QString homeUrl = settings->value("home-url").toString().arg("");
+        QString homeUrl = settings->value("home-url").toString().arg(QString());
         homeUrl.remove(QRegExp("//+$"));
 
         if (request.url().toString().startsWith(homeUrl, Qt::CaseInsensitive)) {
@@ -353,11 +356,11 @@ void Ssu::requestFinished(QNetworkReply *reply)
     }
 }
 
-void Ssu::sendRegistration(QString usernameDomain, QString password)
+void Ssu::sendRegistration(const QString &usernameDomain, const QString &password)
 {
     errorFlag = false;
 
-    QString ssuCaCertificate, ssuRegisterUrl;
+    QString ssuRegisterUrl;
     QString username, domainName;
 
     SsuLog *ssuLog = SsuLog::instance();
@@ -381,7 +384,7 @@ void Ssu::sendRegistration(QString usernameDomain, QString password)
             setDomain(settings->value("default-rnd-domain").toString());
     }
 
-    ssuCaCertificate = SsuRepoManager::caCertificatePath();
+    QString ssuCaCertificate = SsuRepoManager::caCertificatePath();
     if (ssuCaCertificate.isEmpty()) {
         setError("CA certificate for ssu not set ('_ca-certificate in domain')");
         return;
@@ -393,11 +396,12 @@ void Ssu::sendRegistration(QString usernameDomain, QString password)
             setError("URL for ssu registration not set (config key 'register-url')");
             return;
         }
-    } else
+    } else {
         ssuRegisterUrl = settings->value("register-url").toString();
+    }
 
     QString IMEI = deviceInfo.deviceUid();
-    if (IMEI == "") {
+    if (IMEI.isEmpty()) {
         setError("No valid UID available for your device. For phones: is your modem online?");
         return;
     }
@@ -432,10 +436,8 @@ void Ssu::sendRegistration(QString usernameDomain, QString password)
     ssuLog->print(LOG_DEBUG, QString("Sending request to %1")
                   .arg(request.url().url()));
 
-    QNetworkReply *reply;
-
     pendingRequests++;
-    reply = manager->post(request, form.query(QUrl::FullyEncoded).toStdString().c_str());
+    manager->post(request, form.query(QUrl::FullyEncoded).toStdString().c_str());
     // we could expose downloadProgress() from reply in case we want progress info
 
     QString homeUrl = settings->value("home-url").toString().arg(username);
@@ -482,7 +484,7 @@ bool Ssu::setCredentials(QDomDocument *response)
                 credentialScopes.append(scope);
             }
         } else {
-            setError("");
+            setError(QString());
             return false;
         }
     }
@@ -494,7 +496,7 @@ bool Ssu::setCredentials(QDomDocument *response)
     return true;
 }
 
-void Ssu::setError(QString errorMessage)
+void Ssu::setError(const QString &errorMessage)
 {
     errorFlag = true;
     errorString = errorMessage;
@@ -509,7 +511,7 @@ void Ssu::setError(QString errorMessage)
     emit done();
 }
 
-void Ssu::storeAuthorizedKeys(QByteArray data)
+void Ssu::storeAuthorizedKeys(const QByteArray &data)
 {
     QDir dir;
     SsuLog *ssuLog = SsuLog::instance();
@@ -537,8 +539,9 @@ void Ssu::storeAuthorizedKeys(QByteArray data)
         ssuLog->print(LOG_DEBUG, QString("Dropping to %1/%2 for writing authorized keys")
                       .arg(uid_min)
                       .arg(pw->pw_gid));
-    } else
+    } else {
         return;
+    }
 
     homePath = Sandbox::map(homePath);
 
@@ -549,13 +552,14 @@ void Ssu::storeAuthorizedKeys(QByteArray data)
         return;
     }
 
-    if (!dir.exists(homePath + "/.ssh"))
+    if (!dir.exists(homePath + "/.ssh")) {
         if (!dir.mkdir(homePath + "/.ssh")) {
             ssuLog->print(LOG_DEBUG, QString("Unable to create .ssh in %1")
                           .arg(homePath));
             restoreUid();
             return;
         }
+    }
 
     QFile::setPermissions(homePath + "/.ssh",
                           QFile::ReadOwner | QFile::WriteOwner | QFile::ExeOwner);
@@ -579,7 +583,7 @@ void Ssu::updateCredentials(bool force)
 
     SsuLog *ssuLog = SsuLog::instance();
 
-    if (deviceInfo.deviceUid() == "") {
+    if (deviceInfo.deviceUid().isEmpty()) {
         setError("No valid UID available for your device. For phones: is your modem online?");
         return;
     }
@@ -597,8 +601,9 @@ void Ssu::updateCredentials(bool force)
             setError("URL for credentials update not set (config key 'credentials-url')");
             return;
         }
-    } else
+    } else {
         ssuCredentialsUrl = settings->value("credentials-url").toString();
+    }
 
     if (!isRegistered()) {
         setError("Device is not registered.");
@@ -661,8 +666,9 @@ void Ssu::updateStoreCredentials()
         if (settings->value("ignore-credential-errors").toBool() == true) {
             ssuLog->print(LOG_WARNING, QString("Warning: ignore-credential-errors is set, passing auth errors down to libzypp"));
             ssuLog->print(LOG_WARNING, QString("Store credentials not received. %1").arg(reply.error().message()));
-        } else
+        } else {
             setError(QString("Store credentials not received. %1").arg(reply.error().message()));
+        }
     } else {
         SsuCoreConfig *settings = SsuCoreConfig::instance();
         settings->beginGroup("credentials-store");
diff --git a/libssu/ssu.h b/libssu/ssu.h
index 15c4067..2ad61fd 100644
--- a/libssu/ssu.h
+++ b/libssu/ssu.h
@@ -85,7 +85,7 @@ class Ssu: public QObject
      * Find a username/password pair for the given scope
      * @return a QPair with username and password, or an empty QPair if scope is invalid
      */
-    QPair<QString, QString> credentials(QString scope);
+    QPair<QString, QString> credentials(const QString &scope);
     /**
      * Get the scope for a repository, taking into account different scopes for
      * release and RnD repositories
@@ -95,11 +95,11 @@ class Ssu: public QObject
      *
      * @return a string containing the scope; it can be used to look up login credentials using  credentials()
      */
-    QString credentialsScope(QString repoName, bool rndRepo = false);
+    QString credentialsScope(const QString &repoName, bool rndRepo = false);
     /**
      * Return the URL for which credentials scope is valid
      */
-    QString credentialsUrl(QString scope);
+    QString credentialsUrl(const QString &scope);
     /**
      * Returns if the last operation was successful
      * @retval true last operation was successful
@@ -116,7 +116,7 @@ class Ssu: public QObject
      * Resolve a repository url
      * @return the repository URL on success, an empty string on error
      */
-    QString repoUrl(QString repoName, bool rndRepo = false,
+    QString repoUrl(const QString &repoName, bool rndRepo = false,
                     QHash<QString, QString> repoParameters = QHash<QString, QString>(),
                     QHash<QString, QString> parametersOverride = QHash<QString, QString>());
     /**
@@ -146,11 +146,11 @@ class Ssu: public QObject
     /// See SsuCoreConfig::setDeviceMode
     Q_INVOKABLE void setDeviceMode(DeviceModeFlags mode, enum EditMode editMode = Replace);
     /// See SsuCoreConfig::setFlavour
-    Q_INVOKABLE void setFlavour(QString flavour);
+    Q_INVOKABLE void setFlavour(const QString &flavour);
     /// See SsuCoreConfig::setRelease
-    Q_INVOKABLE void setRelease(QString release, bool rnd = false);
+    Q_INVOKABLE void setRelease(const QString &release, bool rnd = false);
     /// See SsuCoreConfig::setDomain
-    Q_INVOKABLE void setDomain(QString domain);
+    Q_INVOKABLE void setDomain(const QString &domain);
     /// See SsuCoreConfig::useSslVerify
     Q_INVOKABLE bool useSslVerify();
 
@@ -162,7 +162,7 @@ class Ssu: public QObject
     bool registerDevice(QDomDocument *response);
     bool setCredentials(QDomDocument *response);
     bool verifyResponse(QDomDocument *response);
-    void storeAuthorizedKeys(QByteArray data);
+    void storeAuthorizedKeys(const QByteArray &data);
 
 private slots:
     void requestFinished(QNetworkReply *reply);
@@ -170,7 +170,7 @@ private slots:
      * Set errorString returned by lastError to errorMessage, set
      * errorFlag returned by error() to true, and emit done()
      */
-    void setError(QString errorMessage);
+    void setError(const QString &errorMessage);
 
 public slots:
     /**
@@ -182,7 +182,7 @@ public slots:
      * error() to check if an error occured, and use lastError() to retrieve the last
      * error message.
      */
-    void sendRegistration(QString username, QString password);
+    void sendRegistration(const QString &username, const QString &password);
     /**
      * Try to update the RND repository credentials. The device needs to be registered
      * for this to work. updateCredentials remembers the time of the last credentials
diff --git a/libssu/ssucoreconfig.cpp b/libssu/ssucoreconfig.cpp
index 153af12..cd1c353 100644
--- a/libssu/ssucoreconfig.cpp
+++ b/libssu/ssucoreconfig.cpp
@@ -25,7 +25,7 @@ SsuCoreConfig *SsuCoreConfig::instance()
     return ssuCoreConfig;
 }
 
-QPair<QString, QString> SsuCoreConfig::credentials(QString scope)
+QPair<QString, QString> SsuCoreConfig::credentials(const QString &scope)
 {
     QPair<QString, QString> ret;
     beginGroup("credentials-" + scope);
@@ -35,7 +35,7 @@ QPair<QString, QString> SsuCoreConfig::credentials(QString scope)
     return ret;
 }
 
-QString SsuCoreConfig::credentialsScope(QString repoName, bool rndRepo)
+QString SsuCoreConfig::credentialsScope(const QString &repoName, bool rndRepo)
 {
     Q_UNUSED(repoName)
     Q_UNUSED(rndRepo)
@@ -46,7 +46,7 @@ QString SsuCoreConfig::credentialsScope(QString repoName, bool rndRepo)
         return "your-configuration-is-broken-and-does-not-contain-credentials-scope";
 }
 
-QString SsuCoreConfig::credentialsUrl(QString scope)
+QString SsuCoreConfig::credentialsUrl(const QString &scope)
 {
     if (contains("credentials-url-" + scope))
         return value("credentials-url-" + scope).toString();
@@ -77,8 +77,9 @@ QString SsuCoreConfig::domain(bool pretty)
             return value("domain").toString().replace(":", "-");
         else
             return value("domain").toString();
-    } else
-        return "";
+    } else {
+        return QString();
+    }
 }
 
 bool SsuCoreConfig::isRegistered()
@@ -111,14 +112,15 @@ void SsuCoreConfig::setDeviceMode(Ssu::DeviceModeFlags mode, enum Ssu::EditMode
         oldMode |= mode;
     } else if ((editMode & Ssu::Remove) == Ssu::Remove) {
         oldMode &= ~mode;
-    } else
+    } else {
         oldMode = mode;
+    }
 
     setValue("deviceMode", oldMode);
     sync();
 }
 
-void SsuCoreConfig::setFlavour(QString flavour)
+void SsuCoreConfig::setFlavour(const QString &flavour)
 {
     setValue("flavour", flavour);
     // flavour is RnD only, so enable RnD mode
@@ -126,7 +128,7 @@ void SsuCoreConfig::setFlavour(QString flavour)
     sync();
 }
 
-void SsuCoreConfig::setRelease(QString release, bool rnd)
+void SsuCoreConfig::setRelease(const QString &release, bool rnd)
 {
     if (rnd) {
         setValue("rndRelease", release);
@@ -139,11 +141,11 @@ void SsuCoreConfig::setRelease(QString release, bool rnd)
     sync();
 }
 
-void SsuCoreConfig::setDomain(QString domain)
+void SsuCoreConfig::setDomain(const QString &domain)
 {
     // - in domain messes with default section autodetection,
     // so change it to :
-    setValue("domain", domain.replace("-", ":"));
+    setValue("domain", QString(domain).replace("-", ":"));
     sync();
 }
 
diff --git a/libssu/ssucoreconfig_p.h b/libssu/ssucoreconfig_p.h
index 1b92a23..e2f238d 100644
--- a/libssu/ssucoreconfig_p.h
+++ b/libssu/ssucoreconfig_p.h
@@ -34,7 +34,7 @@ class SsuCoreConfig: public SsuSettings
      * Find a username/password pair for the given scope
      * @return a QPair with username and password, or an empty QPair if scope is invalid
      */
-    QPair<QString, QString> credentials(QString scope);
+    QPair<QString, QString> credentials(const QString &scope);
     /**
      * Get the scope for a repository, taking into account different scopes for
      * release and RnD repositories
@@ -44,11 +44,11 @@ class SsuCoreConfig: public SsuSettings
      *
      * @return a string containing the scope; it can be used to look up login credentials using  credentials()
      */
-    QString credentialsScope(QString repoName, bool rndRepo = false);
+    QString credentialsScope(const QString &repoName, bool rndRepo = false);
     /**
      * Return the URL for which credentials scope is valid
      */
-    QString credentialsUrl(QString scope);
+    QString credentialsUrl(const QString &scope);
     /**
      * Get the current flavour when RnD repositories are used
      * @return current flavour (usually something like testing, release, ..)
@@ -87,15 +87,15 @@ class SsuCoreConfig: public SsuSettings
     /**
      * Set the flavour used when resolving RND repositories
      */
-    Q_INVOKABLE void setFlavour(QString flavour);
+    Q_INVOKABLE void setFlavour(const QString &flavour);
     /**
      * Set the release version string for either a release, or a RnD snapshot
      */
-    Q_INVOKABLE void setRelease(QString release, bool rnd = false);
+    Q_INVOKABLE void setRelease(const QString &release, bool rnd = false);
     /**
      * Set the domain string (usually something like nemo, jolla, ..)
      */
-    Q_INVOKABLE void setDomain(QString domain);
+    Q_INVOKABLE void setDomain(const QString &domain);
     /**
      * Return configuration settings regarding ssl verification
      * @retval true SSL verification must be used; that's the default if not configured
diff --git a/libssu/ssudeviceinfo.cpp b/libssu/ssudeviceinfo.cpp
index 64ef858..a02b182 100644
--- a/libssu/ssudeviceinfo.cpp
+++ b/libssu/ssudeviceinfo.cpp
@@ -23,7 +23,8 @@
 
 #include "../constants.h"
 
-SsuDeviceInfo::SsuDeviceInfo(QString model): QObject()
+SsuDeviceInfo::SsuDeviceInfo(const QString &model)
+    : QObject()
 {
     boardMappings = new SsuSettings(SSU_BOARD_MAPPING_CONFIGURATION, SSU_BOARD_MAPPING_CONFIGURATION_DIR);
     if (!model.isEmpty())
@@ -101,9 +102,9 @@ QString SsuDeviceInfo::adaptationVariables(const QString &adaptationName, QHash<
 
 void SsuDeviceInfo::clearCache()
 {
-    cachedFamily = "";
-    cachedModel = "";
-    cachedVariant = "";
+    cachedFamily.clear();
+    cachedModel.clear();
+    cachedVariant.clear();
 }
 
 bool SsuDeviceInfo::contains(const QString &model)
@@ -148,13 +149,11 @@ QString SsuDeviceInfo::deviceVariant(bool fallback)
     if (!cachedVariant.isEmpty())
         return cachedVariant;
 
-    cachedVariant = "";
-
     if (boardMappings->contains("variants/" + deviceModel())) {
         cachedVariant = boardMappings->value("variants/" + deviceModel()).toString();
     }
 
-    if (cachedVariant == "" && fallback)
+    if (cachedVariant.isEmpty() && fallback)
         return deviceModel();
 
     return cachedVariant;
@@ -162,19 +161,16 @@ QString SsuDeviceInfo::deviceVariant(bool fallback)
 
 QString SsuDeviceInfo::deviceModel()
 {
-    QDir dir;
-    QFile procCpuinfo;
-    QStringList keys;
-
     if (!cachedModel.isEmpty())
         return cachedModel;
 
     boardMappings->beginGroup("file.exists");
-    keys = boardMappings->allKeys();
+    QStringList keys = boardMappings->allKeys();
 
     // check if the device can be identified by testing for a file
     foreach (const QString &key, keys) {
         QString value = boardMappings->value(key).toString();
+        QDir dir;
         if (dir.exists(Sandbox::map(value))) {
             cachedModel = key;
             break;
@@ -184,6 +180,7 @@ QString SsuDeviceInfo::deviceModel()
     if (!cachedModel.isEmpty()) return cachedModel;
 
     // check if the device can be identified by a string in /proc/cpuinfo
+    QFile procCpuinfo;
     procCpuinfo.setFileName(Sandbox::map("/proc/cpuinfo"));
     procCpuinfo.open(QIODevice::ReadOnly | QIODevice::Text);
     if (procCpuinfo.isOpen()) {
@@ -328,7 +325,7 @@ QString SsuDeviceInfo::deviceUid()
     }
 
     ssuLog->print(LOG_CRIT, "Could not read fallback UID - returning empty string");
-    return "";
+    return QString();
 }
 
 QStringList SsuDeviceInfo::disabledRepos()
@@ -343,13 +340,12 @@ QStringList SsuDeviceInfo::disabledRepos()
     return result;
 }
 
-QString SsuDeviceInfo::displayName(const int type)
+QString SsuDeviceInfo::displayName(int type)
 {
     QString model = deviceModel();
     QString variant = deviceVariant(false);
     QString value, key;
 
-
     switch (type) {
     case Ssu::DeviceManufacturer:
         key = "/deviceManufacturer";
@@ -361,7 +357,7 @@ QString SsuDeviceInfo::displayName(const int type)
         key = "/deviceDesignation";
         break;
     default:
-        return "";
+        return QString();
     }
 
     /*
@@ -374,7 +370,7 @@ QString SsuDeviceInfo::displayName(const int type)
 
     if (boardMappings->contains(model + key))
         value = boardMappings->value(model + key).toString();
-    else if (variant != "" && boardMappings->contains(variant + key))
+    else if (!variant.isEmpty() && boardMappings->contains(variant + key))
         value = boardMappings->value(variant + key).toString();
     else if (boardMappings->contains(key))
         value = boardMappings->value(key).toString();
@@ -433,33 +429,35 @@ QStringList SsuDeviceInfo::repos(bool rnd, int filter)
     return result;
 }
 
-QVariant SsuDeviceInfo::variable(QString section, const QString &key)
+QVariant SsuDeviceInfo::variable(const QString &section, const QString &key)
 {
     /// @todo compat-setting as ssudeviceinfo guaranteed to prepend sections with var-;
     ///       SsuVariables does not have this guarantee. Remove from here as well.
-    if (!section.startsWith("var-"))
-        section = "var-" + section;
+    QString varSection(section);
+    if (!varSection.startsWith("var-"))
+        varSection = "var-" + varSection;
 
-    return SsuVariables::variable(boardMappings, section, key);
+    return SsuVariables::variable(boardMappings, varSection, key);
 }
 
-void SsuDeviceInfo::variableSection(QString section, QHash<QString, QString> *storageHash)
+void SsuDeviceInfo::variableSection(const QString &section, QHash<QString, QString> *storageHash)
 {
-    if (!section.startsWith("var-"))
-        section = "var-" + section;
+    QString varSection(section);
+    if (!varSection.startsWith("var-"))
+        varSection = "var-" + varSection;
 
-    SsuVariables::variableSection(boardMappings, section, storageHash);
+    SsuVariables::variableSection(boardMappings, varSection, storageHash);
 }
 
-void SsuDeviceInfo::setDeviceModel(QString model)
+void SsuDeviceInfo::setDeviceModel(const QString &model)
 {
-    if (model == "")
-        cachedModel = "";
+    if (model.isEmpty())
+        cachedModel.clear();
     else
         cachedModel = model;
 
-    cachedFamily = "";
-    cachedVariant = "";
+    cachedFamily.clear();
+    cachedVariant.clear();
 }
 
 QVariant SsuDeviceInfo::value(const QString &key, const QVariant &value)
diff --git a/libssu/ssudeviceinfo.h b/libssu/ssudeviceinfo.h
index 21ea161..8b3ff7a 100644
--- a/libssu/ssudeviceinfo.h
+++ b/libssu/ssudeviceinfo.h
@@ -22,7 +22,7 @@ class SsuDeviceInfo: public QObject
     /**
      * Initialize with device to override autodetection
      */
-    SsuDeviceInfo(QString model = "");
+    SsuDeviceInfo(const QString &model = QString());
 
     virtual ~SsuDeviceInfo();
 
@@ -30,43 +30,51 @@ class SsuDeviceInfo: public QObject
      * Return the list of adaptations used for the set model
      */
     QStringList adaptationRepos();
+
     /**
      * Resolve adaptation-specific variables for adaptationName, and store them in storageHash
      * Returns "adaptation" if a valid adaptation was found, adaptationName otherwise
      */
     QString adaptationVariables(const QString &adaptationName, QHash<QString, QString> *storageHash);
+
     /**
      * Check if a given model is available in the deviceinfo database, either directly,
      * or as variant. If no model is provided as argument the autodetected or previously
      * set model is used.
      */
-    bool contains(const QString &model = "");
+    bool contains(const QString &model = QString());
+
     /**
      * Try to find the device family for the system this is running on. This function
      * temporarily changes the detected model, and therefore should not be used in a
      * multithreaded environment, unless you like funny results.
      */
     Q_INVOKABLE QString deviceFamily();
+
     /**
      * Try to find the device variant for the system this is running on.
      * If the device is not a variant it will return an empty string. If
      * fallback is set to true it return the device model in this case.
      */
     Q_INVOKABLE QString deviceVariant(bool fallback = false);
+
     /**
      * Try to find out ond what kind of system this is running
      */
     Q_INVOKABLE QString deviceModel();
+
     /**
      * Calculate the device ID used in ssu requests
      * @return The first imei from oFono ModemManager API, if available, or WLAN mac address, or device uid fallback code similar to QDeviceInfo::uniqueDeviceID()
      */
     Q_INVOKABLE QString deviceUid();
+
     /**
      * Return the list of repositories explicitely disabled for this device
      * This does not include repositories only disabled in the user configuration.
      */
     QStringList disabledRepos();
+
     /**
      * Return a string suitable for display in dialogs, ...
      *
@@ -77,7 +85,8 @@ class SsuDeviceInfo: public QObject
      * If no manufacturer is found UNKNOWN is returned.
      * For an invalid type an empty string is returned.
      */
-    Q_INVOKABLE QString displayName(const int type);
+    Q_INVOKABLE QString displayName(int type);
+
     /**
      * Return the complete list of repositories configured for a device.
      * Depending on the filter options, all repostories (user and board),
@@ -85,22 +94,26 @@ class SsuDeviceInfo: public QObject
      * Disabled repositories are excluded depending on filter settings.
      */
     QStringList repos(bool rnd = false, int filter = Ssu::NoFilter);
+
     /**
      * Override device model autodetection
      */
-    Q_INVOKABLE void setDeviceModel(QString model = "");
+    Q_INVOKABLE void setDeviceModel(const QString &model = QString());
+
     /**
      * Return a variable from the given variable section. 'var'- is automatically
      * prepended to the section name if not specified already. Recursive search
      * through several variable sections (specified in the section) is supported,
      * returned will be the first occurence of the variable.
      */
-    QVariant variable(QString section, const QString &key);
+    QVariant variable(const QString &section, const QString &key);
+
     /**
      * Return the requested variable section. 'var-' is automatically
      * prepended to the section name if not specified already.
      */
-    void variableSection(QString section, QHash<QString, QString> *storageHash);
+    void variableSection(const QString &section, QHash<QString, QString> *storageHash);
+
     /**
      * Return a value from an adaptation section. Returns an empty string
      * or a given default value if key does not exist.
@@ -111,7 +124,6 @@ class SsuDeviceInfo: public QObject
      */
     QVariant value(const QString &key, const QVariant &value = QVariant());
 
-
 private:
     SsuSettings *boardMappings;
     QString cachedFamily, cachedModel, cachedVariant;
diff --git a/libssu/ssufeaturemanager.cpp b/libssu/ssufeaturemanager.cpp
index 42baee5..6121aa7 100644
--- a/libssu/ssufeaturemanager.cpp
+++ b/libssu/ssufeaturemanager.cpp
@@ -18,7 +18,8 @@
 
 #include "../constants.h"
 
-SsuFeatureManager::SsuFeatureManager(): QObject()
+SsuFeatureManager::SsuFeatureManager()
+    : QObject()
 {
     featureSettings = new SsuSettings(SSU_FEATURE_CONFIGURATION, SSU_FEATURE_CONFIGURATION_DIR);
 }
@@ -57,7 +58,7 @@ QStringList SsuFeatureManager::repos(bool rndRepo, int filter)
     return r;
 }
 
-QString SsuFeatureManager::url(QString repo, bool rndRepo)
+QString SsuFeatureManager::url(const QString &repo, bool rndRepo)
 {
     QString repoHeader = QString("repositories-%1/")
                          .arg(rndRepo ? "rnd" : "release");
@@ -67,5 +68,5 @@ QString SsuFeatureManager::url(QString repo, bool rndRepo)
     else if (featureSettings->contains("repositories/" + repo))
         return featureSettings->value("repositories/" + repo).toString();
 
-    return "";
+    return QString();
 }
diff --git a/libssu/ssufeaturemanager.h b/libssu/ssufeaturemanager.h
index c9e4544..8495b1f 100644
--- a/libssu/ssufeaturemanager.h
+++ b/libssu/ssufeaturemanager.h
@@ -22,7 +22,7 @@ class SsuFeatureManager: public QObject
 public:
     SsuFeatureManager();
     QStringList repos(bool rndRepo, int filter = Ssu::NoFilter);
-    QString url(QString repo, bool rndRepo);
+    QString url(const QString &repo, bool rndRepo);
 
 private:
     SsuSettings *featureSettings;
diff --git a/libssu/ssufeaturemodel.cpp b/libssu/ssufeaturemodel.cpp
index d46aad9..bf302af 100644
--- a/libssu/ssufeaturemodel.cpp
+++ b/libssu/ssufeaturemodel.cpp
@@ -51,7 +51,7 @@ class SsuFeatureModelPrivate
                     if (keys.contains("version")) {
                         feature.insert("version", settings.value("version").toString());
                     } else {
-                        feature.insert("version", QString(""));
+                        feature.insert("version", QString());
                     }
                     features.append(feature);
                 }
diff --git a/libssu/ssulog.cpp b/libssu/ssulog.cpp
index 64b395c..bc8bd09 100644
--- a/libssu/ssulog.cpp
+++ b/libssu/ssulog.cpp
@@ -24,11 +24,8 @@ SsuLog *SsuLog::instance()
     return ssuLog;
 }
 
-void SsuLog::print(int priority, QString message)
+void SsuLog::print(int priority, const QString &message)
 {
-    QByteArray ba = message.toUtf8();
-    const char *ca = ba.constData();
-
     // directly go through qsettings here to avoid recursive invocation
     // of coreconfig / ssulog
     if (ssuLogLevel == -1) {
@@ -45,7 +42,10 @@ void SsuLog::print(int priority, QString message)
     if (priority > ssuLogLevel)
         return;
 
-    if (sd_journal_print(priority, "ssu: %s", ca) < 0 && fallbackLogPath != "") {
+    QByteArray ba = message.toUtf8();
+    const char *ca = ba.constData();
+
+    if (sd_journal_print(priority, "ssu: %s", ca) < 0 && !fallbackLogPath.isEmpty()) {
         QFile logfile;
         QTextStream logstream;
         logfile.setFileName(fallbackLogPath);
diff --git a/libssu/ssulog_p.h b/libssu/ssulog_p.h
index 250ba6b..c78193d 100644
--- a/libssu/ssulog_p.h
+++ b/libssu/ssulog_p.h
@@ -20,7 +20,7 @@ class SsuLog
     /**
      * Print a message to systemds journal, or to a text log file, if a fallback is defined
      */
-    void print(int priority, QString message);
+    void print(int priority, const QString &message);
 
 private:
     SsuLog() {}
diff --git a/libssu/ssurepomanager.cpp b/libssu/ssurepomanager.cpp
index 4774d8b..9b246ae 100644
--- a/libssu/ssurepomanager.cpp
+++ b/libssu/ssurepomanager.cpp
@@ -21,12 +21,12 @@
 
 #include "../constants.h"
 
-SsuRepoManager::SsuRepoManager(): QObject()
+SsuRepoManager::SsuRepoManager()
+    : QObject()
 {
-
 }
 
-int SsuRepoManager::add(QString repo, QString repoUrl)
+int SsuRepoManager::add(const QString &repo, const QString &repoUrl)
 {
     SsuCoreConfig *ssuSettings = SsuCoreConfig::instance();
 
@@ -38,7 +38,7 @@ int SsuRepoManager::add(QString repo, QString repoUrl)
     if ((ssuSettings->deviceMode() & Ssu::AppInstallMode) == Ssu::AppInstallMode)
         return -1;
 
-    if (repoUrl == "") {
+    if (repoUrl.isEmpty()) {
         // just enable a repository which has URL in repos.ini
         QStringList enabledRepos;
         if (ssuSettings->contains("enabled-repos"))
@@ -47,22 +47,21 @@ int SsuRepoManager::add(QString repo, QString repoUrl)
         enabledRepos.append(repo);
         enabledRepos.removeDuplicates();
         ssuSettings->setValue("enabled-repos", enabledRepos);
-    } else
+    } else {
         ssuSettings->setValue("repository-urls/" + repo, repoUrl);
+    }
 
     ssuSettings->sync();
     return 0;
 }
 
-QString SsuRepoManager::caCertificatePath(QString domain)
+QString SsuRepoManager::caCertificatePath(const QString &domain)
 {
     SsuCoreConfig *settings = SsuCoreConfig::instance();
     SsuSettings repoSettings(SSU_REPO_CONFIGURATION, QSettings::IniFormat);
 
-    if (domain.isEmpty())
-        domain = settings->domain();
-
-    QString ca = SsuVariables::variable(&repoSettings, domain + "-domain",
+    QString ca = SsuVariables::variable(&repoSettings,
+                                        (domain.isEmpty() ? settings->domain() : domain) + "-domain",
                                         "_ca-certificate").toString();
     if (!ca.isEmpty())
         return ca;
@@ -71,10 +70,10 @@ QString SsuRepoManager::caCertificatePath(QString domain)
     if (settings->contains("ca-certificate"))
         return settings->value("ca-certificate").toString();
 
-    return "";
+    return QString();
 }
 
-int SsuRepoManager::disable(QString repo)
+int SsuRepoManager::disable(const QString &repo)
 {
     SsuCoreConfig *ssuSettings = SsuCoreConfig::instance();
     QStringList disabledRepos;
@@ -91,7 +90,7 @@ int SsuRepoManager::disable(QString repo)
     return 0;
 }
 
-int SsuRepoManager::enable(QString repo)
+int SsuRepoManager::enable(const QString &repo)
 {
     SsuCoreConfig *ssuSettings = SsuCoreConfig::instance();
     QStringList disabledRepos;
@@ -108,7 +107,7 @@ int SsuRepoManager::enable(QString repo)
     return 0;
 }
 
-int SsuRepoManager::remove(QString repo)
+int SsuRepoManager::remove(const QString &repo)
 {
     SsuCoreConfig *ssuSettings = SsuCoreConfig::instance();
 
@@ -190,8 +189,7 @@ QStringList SsuRepoManager::repos(bool rnd, SsuDeviceInfo &deviceInfo, int filte
         appInstallMode = true;
     }
 
-    if (filter == Ssu::NoFilter ||
-            filter == Ssu::UserFilter) {
+    if (filter == Ssu::NoFilter || filter == Ssu::UserFilter) {
         // user defined repositories, or ones overriding URLs for default ones
         // -> in update mode we need to check for each of those if it already
         //    exists. If it exists, keep it, if it does not, disable it
@@ -242,23 +240,19 @@ void SsuRepoManager::update()
     // - delete all non-ssu managed repositories (missing ssu_ prefix)
     // - create list of ssu-repositories for current adaptation
     // - go through ssu_* repositories, delete all which are not in the list; write others
-
-    SsuDeviceInfo deviceInfo;
-    QStringList ssuFilters;
-
     SsuCoreConfig *ssuSettings = SsuCoreConfig::instance();
     int deviceMode = ssuSettings->deviceMode();
 
     SsuLog *ssuLog = SsuLog::instance();
 
-    // if device is misconfigured, always assume release mode
-    bool rndMode = false;
-
     if ((deviceMode & Ssu::DisableRepoManager) == Ssu::DisableRepoManager) {
         ssuLog->print(LOG_INFO, "Repo management requested, but not enabled (option 'deviceMode')");
         return;
     }
 
+    // if device is misconfigured, always assume release mode
+    bool rndMode = false;
+
     if ((deviceMode & Ssu::RndMode) == Ssu::RndMode)
         rndMode = true;
 
@@ -280,10 +274,11 @@ void SsuRepoManager::update()
     }
 
     // ... delete all ssu-managed repositories not valid for this device ...
+    QStringList ssuFilters;
     ssuFilters.append("ssu_*");
     QDirIterator it(Sandbox::map(ZYPP_REPO_PATH), ssuFilters);
     while (it.hasNext()) {
-        QString f = it.next();
+        it.next();
 
         QStringList parts = it.fileName().split("_");
         // repo file structure is ssu_<reponame>_<rnd|release>.repo -> splits to 3 parts
@@ -291,8 +286,9 @@ void SsuRepoManager::update()
             if (!repositoryList.contains(parts.at(1)) ||
                     parts.at(2) != (rndMode ? "rnd.repo" : "release.repo" ))
                 QFile(it.filePath()).remove();
-        } else
+        } else {
             QFile(it.filePath()).remove();
+        }
     }
 
     // ... and create all repositories required for this device
@@ -311,7 +307,7 @@ void SsuRepoManager::update()
                                .arg(repo)
                                .arg(rndMode ? "rnd" : "release");
 
-        if (url(repoName, rndMode) == "") {
+        if (url(repoName, rndMode).isEmpty()) {
             // TODO, repositories should only be disabled if they're not required
             //       for this machine. For required repositories error is better
             QTextStream qerr(stderr);
@@ -391,15 +387,10 @@ QStringList SsuRepoManager::repoVariables(QHash<QString, QString> *storageHash,
 
 // RND repos have flavour (devel, testing, release), and release (latest, next)
 // Release repos only have release (latest, next, version number)
-QString SsuRepoManager::url(QString repoName, bool rndRepo,
+QString SsuRepoManager::url(const QString &repoName, bool rndRepo,
                             QHash<QString, QString> repoParameters,
                             QHash<QString, QString> parametersOverride)
 {
-    QString r;
-    QStringList configSections;
-    SsuVariables var;
-    SsuCoreConfig *settings = SsuCoreConfig::instance();
-    SsuSettings repoSettings(SSU_REPO_CONFIGURATION, QSettings::IniFormat);
     SsuDeviceInfo deviceInfo;
 
     // set debugSplit for incorrectly configured debuginfo repositories (debugSplit
@@ -408,8 +399,7 @@ QString SsuRepoManager::url(QString repoName, bool rndRepo,
     if (repoName.endsWith("-debuginfo") && !repoParameters.contains("debugSplit"))
         repoParameters.insert("debugSplit", "debug");
 
-    configSections = repoVariables(&repoParameters, rndRepo);
-
+    QStringList configSections = repoVariables(&repoParameters, rndRepo);
 
     // Override device model (and therefore all the family, ... stuff)
     if (parametersOverride.contains("model"))
@@ -418,19 +408,22 @@ QString SsuRepoManager::url(QString repoName, bool rndRepo,
     repoParameters.insert("deviceFamily", deviceInfo.deviceFamily());
     repoParameters.insert("deviceModel", deviceInfo.deviceModel());
 
-    repoName = deviceInfo.adaptationVariables(repoName, &repoParameters);
-
+    QString adaptationRepoName = deviceInfo.adaptationVariables(repoName, &repoParameters);
 
+    SsuCoreConfig *settings = SsuCoreConfig::instance();
     QString domain;
+
     if (parametersOverride.contains("domain")) {
         domain = parametersOverride.value("domain");
         domain.replace("-", ":");
-    } else
+    } else {
         domain = settings->domain();
+    }
 
     // variableSection does autodetection for the domain default section
-    var.variableSection(&repoSettings,
-                        domain + "-domain", &repoParameters);
+    SsuSettings repoSettings(SSU_REPO_CONFIGURATION, QSettings::IniFormat);
+    SsuVariables var;
+    var.variableSection(&repoSettings, domain + "-domain", &repoParameters);
 
     // override arbitrary variables, mostly useful for generating mic URLs
     QHash<QString, QString>::const_iterator i = parametersOverride.constBegin();
@@ -445,16 +438,17 @@ QString SsuRepoManager::url(QString repoName, bool rndRepo,
     // 3. URLs from repos.ini
 
     SsuFeatureManager featureManager;
+    QString r;
 
-    if (settings->contains("repository-urls/" + repoName))
-        r = settings->value("repository-urls/" + repoName).toString();
-    else if (featureManager.url(repoName, rndRepo) != "")
-        r = featureManager.url(repoName, rndRepo);
-    else {
+    if (settings->contains("repository-urls/" + adaptationRepoName)) {
+        r = settings->value("repository-urls/" + adaptationRepoName).toString();
+    } else if (!featureManager.url(adaptationRepoName, rndRepo).isEmpty()) {
+        r = featureManager.url(adaptationRepoName, rndRepo);
+    } else {
         foreach (const QString &section, configSections) {
             repoSettings.beginGroup(section);
-            if (repoSettings.contains(repoName)) {
-                r = repoSettings.value(repoName).toString();
+            if (repoSettings.contains(adaptationRepoName)) {
+                r = repoSettings.value(adaptationRepoName).toString();
                 repoSettings.endGroup();
                 break;
             }
diff --git a/libssu/ssurepomanager.h b/libssu/ssurepomanager.h
index 064fe0e..5ef448d 100644
--- a/libssu/ssurepomanager.h
+++ b/libssu/ssurepomanager.h
@@ -29,7 +29,7 @@ class SsuRepoManager: public QObject
      *
      * If the device is in UpdateMode this function does nothing.
      */
-    int add(QString repo, QString repoUrl = "");
+    int add(const QString &repo, const QString &repoUrl = QString());
     /**
      * Return the path to the CA certificate to be used for the given domain,
      * or default domain, if omitted
@@ -38,7 +38,7 @@ class SsuRepoManager: public QObject
      * @retval -1 Repository not added because device is in update mode
      * @retval -2 Repository not added because third party repositories are disabled
      */
-    static QString caCertificatePath(QString domain = "");
+    static QString caCertificatePath(const QString &domain = QString());
     /**
      * Disable a repository
      *
@@ -46,7 +46,7 @@ class SsuRepoManager: public QObject
      * @retval -1 Request ignored because device is in update mode
      * @retval -2 Request ignored because 3rd party repositories are disabled
      */
-    int disable(QString repo);
+    int disable(const QString &repo);
     /**
      * Enable a repository, given it's not disabled by board configuration
      *
@@ -54,7 +54,7 @@ class SsuRepoManager: public QObject
      * @retval -1 Request ignored because device is in update mode
      * @retval -2 Request ignored because 3rd party repositories are disabled
      */
-    int enable(QString repo);
+    int enable(const QString &repo);
     /**
      * Remove a repository
      *
@@ -62,7 +62,7 @@ class SsuRepoManager: public QObject
      * @retval -1 Request ignored because device is in update mode
      * @retval -2 Request ignored because 3rd party repositories are disabled
      */
-    int remove(QString repo);
+    int remove(const QString &repo);
     /**
      * Collect the list of repositories from different submodules
      */
@@ -94,7 +94,7 @@ class SsuRepoManager: public QObject
      * Resolve a repository url
      * @return the repository URL on success, an empty string on error
      */
-    QString url(QString repoName, bool rndRepo = false,
+    QString url(const QString &repoName, bool rndRepo = false,
                 QHash<QString, QString> repoParameters = QHash<QString, QString>(),
                 QHash<QString, QString> parametersOverride = QHash<QString, QString>());
 
diff --git a/libssu/ssusettings.cpp b/libssu/ssusettings.cpp
index 602fcf3..da8ad4c 100644
--- a/libssu/ssusettings.cpp
+++ b/libssu/ssusettings.cpp
@@ -14,26 +14,25 @@
 #include "ssusettings_p.h"
 #include "ssulog_p.h"
 
-SsuSettings::SsuSettings(): QSettings()
+SsuSettings::SsuSettings()
+    : QSettings()
 {
-
 }
 
-SsuSettings::SsuSettings(const QString &fileName, Format format, QObject *parent):
-    QSettings(Sandbox::map(fileName), format, parent)
+SsuSettings::SsuSettings(const QString &fileName, Format format, QObject *parent)
+    : QSettings(Sandbox::map(fileName), format, parent)
 {
-
 }
 
-SsuSettings::SsuSettings(const QString &fileName, Format format, const QString &defaultFileName, QObject *parent):
-    QSettings(Sandbox::map(fileName), format, parent)
+SsuSettings::SsuSettings(const QString &fileName, Format format, const QString &defaultFileName, QObject *parent)
+    : QSettings(Sandbox::map(fileName), format, parent)
 {
     defaultSettingsFile = Sandbox::map(defaultFileName);
     upgrade();
 }
 
-SsuSettings::SsuSettings(const QString &fileName, const QString &settingsDirectory, QObject *parent):
-    QSettings(Sandbox::map(fileName), QSettings::IniFormat, parent)
+SsuSettings::SsuSettings(const QString &fileName, const QString &settingsDirectory, QObject *parent)
+    : QSettings(Sandbox::map(fileName), QSettings::IniFormat, parent)
 {
     settingsd = Sandbox::map(settingsDirectory);
     merge();
@@ -41,7 +40,7 @@ SsuSettings::SsuSettings(const QString &fileName, const QString &settingsDirecto
 
 void SsuSettings::merge(bool keepOld)
 {
-    if (settingsd == "")
+    if (settingsd.isEmpty())
         return;
 
     bool skipMerge = true;
@@ -112,14 +111,14 @@ void SsuSettings::merge(QSettings *masterSettings, const QStringList &settingsFi
  */
 void SsuSettings::upgrade()
 {
+    if (defaultSettingsFile.isEmpty())
+        return;
+
     int configVersion = 0;
     int defaultConfigVersion = 0;
 
     SsuLog *ssuLog = SsuLog::instance();
 
-    if (defaultSettingsFile == "")
-        return;
-
     QSettings defaultSettings(defaultSettingsFile, QSettings::IniFormat);
 
     if (contains("configVersion"))
@@ -133,13 +132,13 @@ void SsuSettings::upgrade()
                       .arg(defaultConfigVersion));
 
         for (int i = configVersion + 1; i <= defaultConfigVersion; i++) {
-            QStringList defaultKeys;
             QString currentSection = QString("%1/").arg(i);
 
             ssuLog->print(LOG_DEBUG, QString("Processing configuration version %1").arg(i));
             defaultSettings.beginGroup(currentSection);
-            defaultKeys = defaultSettings.allKeys();
+            QStringList defaultKeys = defaultSettings.allKeys();
             defaultSettings.endGroup();
+
             foreach (const QString &key, defaultKeys) {
                 // Default keys support both commands and new keys
                 if (key.compare("cmd-remove", Qt::CaseSensitive) == 0) {
diff --git a/libssu/ssuvariables.cpp b/libssu/ssuvariables.cpp
index 8a14666..1b763c7 100644
--- a/libssu/ssuvariables.cpp
+++ b/libssu/ssuvariables.cpp
@@ -14,12 +14,12 @@
 
 #include "../constants.h"
 
-SsuVariables::SsuVariables(): QObject()
+SsuVariables::SsuVariables()
+    : QObject()
 {
-
 }
 
-QString SsuVariables::defaultSection(SsuSettings *settings, QString section)
+QString SsuVariables::defaultSection(SsuSettings *settings, const QString &section)
 {
     QStringList parts = section.split("-");
 
@@ -33,10 +33,10 @@ QString SsuVariables::defaultSection(SsuSettings *settings, QString section)
     if (settings->childGroups().contains(key))
         return key;
     else
-        return "";
+        return QString();
 }
 
-QString SsuVariables::resolveString(QString pattern, QHash<QString, QString> *variables, int recursionDepth)
+QString SsuVariables::resolveString(const QString &pattern, QHash<QString, QString> *variables, int recursionDepth)
 {
     if (recursionDepth >= SSU_MAX_RECURSION) {
         return "maximum-recursion-level-reached";
@@ -46,13 +46,15 @@ QString SsuVariables::resolveString(QString pattern, QHash<QString, QString> *va
     regex.setMinimal(true);
 
     int pos = 0;
-    while ((pos = regex.indexIn(pattern, pos)) != -1) {
+    QString result(pattern);
+
+    while ((pos = regex.indexIn(result, pos)) != -1) {
         QString match = regex.cap(0);
 
         if (match.contains(":")) {
             // variable is special, resolve before replacing
             QString variable = resolveVariable(match, variables);
-            pattern.replace(match, variable);
+            result.replace(match, variable);
             pos += variable.length();
         } else {
             // look up variable name in hashmap, and replace it with stored value,
@@ -61,37 +63,39 @@ QString SsuVariables::resolveString(QString pattern, QHash<QString, QString> *va
             variableName.remove(0, 2);
             variableName.chop(1);
             if (variables->contains(variableName)) {
-                pattern.replace(match, variables->value(variableName));
+                result.replace(match, variables->value(variableName));
                 pos += variables->value(variableName).length();
-            } else
-                pattern.replace(match, "");
+            } else {
+                result.replace(match, "");
+            }
         }
     }
 
     // check if string still contains variables, and recurse
-    if (regex.indexIn(pattern, 0) != -1)
-        pattern = resolveString(pattern, variables, recursionDepth + 1);
+    if (regex.indexIn(result, 0) != -1)
+        result = resolveString(result, variables, recursionDepth + 1);
 
-    return pattern;
+    return result;
 }
 
-QString SsuVariables::resolveVariable(QString variable, QHash<QString, QString> *variables)
+QString SsuVariables::resolveVariable(const QString &variable, QHash<QString, QString> *variables)
 {
-    QString variableValue = "";
+    QString variableValue;
+    QString filteredVariable(variable);
 
-    if (variable.endsWith(")"))
-        variable.chop(1);
-    if (variable.startsWith("%("))
-        variable.remove(0, 2);
+    if (filteredVariable.endsWith(")"))
+        filteredVariable.chop(1);
+    if (filteredVariable.startsWith("%("))
+        filteredVariable.remove(0, 2);
 
     // hunt for your colon
-    int magic = variable.indexOf(":");
+    int magic = filteredVariable.indexOf(":");
 
     // seems you misplaced your colon
-    if (magic == -1) return variable;
+    if (magic == -1) return filteredVariable;
 
-    QStringRef variableName(&variable, 0, magic);
-    QStringRef variableSub(&variable, magic + 2, variable.length() - magic - 2);
+    QStringRef variableName(&filteredVariable, 0, magic);
+    QStringRef variableSub(&filteredVariable, magic + 2, filteredVariable.length() - magic - 2);
 
     // Fill in variable value for later tests, if it exists
     if (variables->contains(variableName.toString()))
@@ -99,18 +103,18 @@ QString SsuVariables::resolveVariable(QString variable, QHash<QString, QString>
 
     // find the operator who's after your colon
     QChar op;
-    if (variable.length() > magic + 1)
-        op = variable.at(magic + 1);
+    if (filteredVariable.length() > magic + 1)
+        op = filteredVariable.at(magic + 1);
 
     switch (op.toLatin1()) {
     case '-':
         // substitute default value if variable is empty
-        if (variableValue == "")
+        if (variableValue.isEmpty())
             return variableSub.toString();
         break;
     case '+':
         // substitute default value if variable is not empty
-        if (variableValue != "")
+        if (!variableValue.isEmpty())
             return variableSub.toString();
         break;
     case '=': {
@@ -143,7 +147,7 @@ SsuSettings *SsuVariables::settings()
 }
 
 /// @todo add override capability with an override-section in ssu.ini
-QVariant SsuVariables::variable(QString section, const QString &key)
+QVariant SsuVariables::variable(const QString &section, const QString &key)
 {
     if (m_settings != NULL)
         return variable(m_settings, section, key);
@@ -151,11 +155,9 @@ QVariant SsuVariables::variable(QString section, const QString &key)
         return QVariant();
 }
 
-QVariant SsuVariables::variable(SsuSettings *settings, QString section, const QString &key)
+QVariant SsuVariables::variable(SsuSettings *settings, const QString &section, const QString &key)
 {
-    QVariant value;
-
-    value = readVariable(settings, section, key, 0);
+    QVariant value = readVariable(settings, section, key, 0);
 
     // first check if the value is defined in the main section, and fall back
     // to default sections
@@ -168,19 +170,18 @@ QVariant SsuVariables::variable(SsuSettings *settings, QString section, const QS
     return value;
 }
 
-void SsuVariables::variableSection(QString section, QHash<QString, QString> *storageHash)
+void SsuVariables::variableSection(const QString &section, QHash<QString, QString> *storageHash)
 {
     if (m_settings != NULL)
         variableSection(m_settings, section, storageHash);
 }
 
-void SsuVariables::variableSection(SsuSettings *settings, QString section, QHash<QString, QString> *storageHash)
+void SsuVariables::variableSection(SsuSettings *settings, const QString &section, QHash<QString, QString> *storageHash)
 {
-
     QString dSection = defaultSection(settings, section);
-    if (dSection.isEmpty())
+    if (dSection.isEmpty()) {
         readSection(settings, section, storageHash, 0);
-    else {
+    } else {
         readSection(settings, dSection, storageHash, 0);
         readSection(settings, section, storageHash, 0, false);
     }
@@ -190,7 +191,7 @@ void SsuVariables::variableSection(SsuSettings *settings, QString section, QHash
 // variables which exist in more than one section will get overwritten when discovered
 // again
 // the section itself gets evaluated at the end, again having a chance to overwrite variables
-void SsuVariables::readSection(SsuSettings *settings, QString section,
+void SsuVariables::readSection(SsuSettings *settings, const QString &section,
                                QHash<QString, QString> *storageHash, int recursionDepth,
                                bool logOverride)
 {
@@ -250,7 +251,7 @@ void SsuVariables::readSection(SsuSettings *settings, QString section,
     settings->endGroup();
 }
 
-QVariant SsuVariables::readVariable(SsuSettings *settings, QString section, const QString &key,
+QVariant SsuVariables::readVariable(SsuSettings *settings, const QString &section, const QString &key,
                                     int recursionDepth, bool logOverride)
 {
     Q_UNUSED(logOverride)
diff --git a/libssu/ssuvariables_p.h b/libssu/ssuvariables_p.h
index 5a9c92e..7f68d6e 100644
--- a/libssu/ssuvariables_p.h
+++ b/libssu/ssuvariables_p.h
@@ -26,15 +26,15 @@ class SsuVariables: public QObject
      * the first token (or second token for "var-" sections) replaced with
      * "default". You should therefore avoid "-" in section names.
      */
-    static QString defaultSection(SsuSettings *settings, QString section);
+    static QString defaultSection(SsuSettings *settings, const QString &section);
     /**
      * Resolve a whole string, containing several variables. Variables inside variables are allowed
      */
-    static QString resolveString(QString pattern, QHash<QString, QString> *variables, int recursionDepth = 0);
+    static QString resolveString(const QString &pattern, QHash<QString, QString> *variables, int recursionDepth = 0);
     /**
      * Resolve variables; variable can be passed as %(var) or var
      */
-    static QString resolveVariable(QString variable, QHash<QString, QString> *variables);
+    static QString resolveVariable(const QString &variable, QHash<QString, QString> *variables);
     /**
      * Set the settings object to use
      */
@@ -49,8 +49,8 @@ class SsuVariables: public QObject
      * through several variable sections (specified in the section) is supported,
      * returned will be the last occurence of the variable.
      */
-    QVariant variable(QString section, const QString &key);
-    static QVariant variable(SsuSettings *settings, QString section, const QString &key);
+    QVariant variable(const QString &section, const QString &key);
+    static QVariant variable(SsuSettings *settings, const QString &section, const QString &key);
     /**
      * Return the requested variable section, recursively looking up all variable
      * sections referenced inside with the 'variable' keyword. 'var-' is automatically
@@ -64,15 +64,15 @@ class SsuVariables: public QObject
      * This function tries to identify a default configuration section, and merges
      * the default section with the requested section.
      */
-    void variableSection(QString section, QHash<QString, QString> *storageHash);
-    static void variableSection(SsuSettings *settings, QString section,
+    void variableSection(const QString &section, QHash<QString, QString> *storageHash);
+    static void variableSection(SsuSettings *settings, const QString &section,
                                 QHash<QString, QString> *storageHash);
 
 private:
-    static void readSection(SsuSettings *settings, QString section,
+    static void readSection(SsuSettings *settings, const QString &section,
                             QHash<QString, QString> *storageHash, int recursionDepth,
                             bool logOverride = true);
-    static QVariant readVariable(SsuSettings *settings, QString section, const QString &key,
+    static QVariant readVariable(SsuSettings *settings, const QString &section, const QString &key,
                                  int recursionDepth, bool logOverride = true);
     SsuSettings *m_settings;
 };
diff --git a/ssucli/ssucli.cpp b/ssucli/ssucli.cpp
index bce565d..23cf14e 100644
--- a/ssucli/ssucli.cpp
+++ b/ssucli/ssucli.cpp
@@ -19,7 +19,8 @@
 
 #include "ssucli.h"
 
-SsuCli::SsuCli(): QObject()
+SsuCli::SsuCli()
+    : QObject()
 {
     connect(this, SIGNAL(done()),
             QCoreApplication::instance(), SLOT(quit()), Qt::DirectConnection);
@@ -171,7 +172,6 @@ void SsuCli::optMode(QStringList opt)
 void SsuCli::optModel(QStringList opt)
 {
     QTextStream qout(stdout);
-    QTextStream qerr(stderr);
     SsuDeviceInfo deviceInfo;
 
     if (opt.count() == 3 && opt.at(2) == "-s") {
@@ -186,7 +186,6 @@ void SsuCli::optModel(QStringList opt)
 void SsuCli::optModifyRepo(enum Actions action, QStringList opt)
 {
     SsuRepoManager repoManager;
-    QTextStream qout(stdout);
     QTextStream qerr(stderr);
 
     if (opt.count() == 3) {
@@ -341,7 +340,7 @@ void SsuCli::optRepos(QStringList opt)
     SsuRepoManager repoManager;
     SsuDeviceInfo deviceInfo;
     QHash<QString, QString> repoParameters, repoOverride;
-    QString device = "";
+    QString device;
     bool rndRepo = false;
     int micMode = 0, flagStart = 0;
 
@@ -398,7 +397,7 @@ void SsuCli::optRepos(QStringList opt)
             rndRepo = false;
     }
 
-    if (device != "") {
+    if (!device.isEmpty()) {
         deviceInfo.setDeviceModel(device);
         repoOverride.insert("model", device);
     }
@@ -414,8 +413,9 @@ void SsuCli::optRepos(QStringList opt)
             if (repo.endsWith("-debuginfo")) {
                 repoName = repo.left(repo.size() - 10);
                 repoParameters.insert("debugSplit", "debug");
-            } else if (repoParameters.value("debugSplit") == "debug")
+            } else if (repoParameters.value("debugSplit") == "debug") {
                 repoParameters.remove("debugSplit");
+            }
 
             QString repoUrl = ssu.repoUrl(repoName, rndRepo, repoParameters, repoOverride);
             qout << "repo --name=" << repo << "-"
@@ -427,9 +427,9 @@ void SsuCli::optRepos(QStringList opt)
         return;
     }
 
-    if (device.isEmpty())
+    if (device.isEmpty()) {
         repos = repoManager.repos(rndRepo, deviceInfo, Ssu::BoardFilterUserBlacklist);
-    else {
+    } else {
         qout << "Printing repository configuration for '" << device << "'" << endl << endl;
         repos = repoManager.repos(rndRepo, deviceInfo, Ssu::BoardFilter);
     }
@@ -459,7 +459,7 @@ void SsuCli::optRepos(QStringList opt)
         }
 
         if (i == 0) {
-            if (device != "") {
+            if (!device.isEmpty()) {
                 repos.clear();
                 continue;
             }
@@ -473,7 +473,7 @@ void SsuCli::optRepos(QStringList opt)
                 qout << endl << "Disabled repositories (global): " << endl;
         } else if (i == 2) {
             repos.clear();
-            if (device != "")
+            if (!device.isEmpty())
                 continue;
             if (ssuSettings->contains("disabled-repos"))
                 repos.append(ssuSettings->value("disabled-repos").toStringList());
@@ -553,7 +553,7 @@ void SsuCli::optStatus(QStringList opt)
     qout << "Device model: " << deviceInfo.displayName(Ssu::DeviceModel) << " ("
          << deviceInfo.deviceModel() << " / "
          << deviceInfo.displayName(Ssu::DeviceDesignation) << ")" << endl;
-    if (deviceInfo.deviceVariant() != "")
+    if (!deviceInfo.deviceVariant().isEmpty())
         qout << "Device variant: " << deviceInfo.deviceVariant() << endl;
     qout << "Device UID: " << deviceUid << endl;
     if ((ssu.deviceMode() & Ssu::RndMode) == Ssu::RndMode)
@@ -602,7 +602,6 @@ void SsuCli::optUpdateRepos(QStringList opt)
 
 void SsuCli::run()
 {
-    QTextStream qout(stdout);
     QTextStream qerr(stderr);
 
     QStringList arguments = QCoreApplication::arguments();
@@ -684,18 +683,15 @@ void SsuCli::run()
         usage();
 }
 
-void SsuCli::uidWarning(QString message)
+void SsuCli::uidWarning()
 {
-    if (message.isEmpty())
-        message = "Run 'ssu ur' as root to recreate repository files";
-
     if (geteuid() != 0) {
         QTextStream qout(stderr);
-        qout << "You're not root. " << message << endl;
+        qout << "You're not root. Run 'ssu ur' as root to recreate repository files" << endl;
     }
 }
 
-void SsuCli::usage(QString message)
+void SsuCli::usage(const QString &message)
 {
     QTextStream qout(stderr);
     qout << "\nUsage: ssu <command> [-command-options] [arguments]" << endl
diff --git a/ssucli/ssucli.h b/ssucli/ssucli.h
index d9de605..924557a 100644
--- a/ssucli/ssucli.h
+++ b/ssucli/ssucli.h
@@ -32,8 +32,8 @@ public slots:
     SsuProxy *ssuProxy;
     QSettings settings;
     int state;
-    void usage(QString message = "");
-    void uidWarning(QString message = "");
+    void usage(const QString &message = QString());
+    void uidWarning();
     void optDomain(QStringList opt);
     void optFlavour(QStringList opt);
     void optMode(QStringList opt);
@@ -47,10 +47,10 @@ public slots:
     void optUpdateRepos(QStringList opt);
 
     enum Actions {
-        Remove  = 0,
-        Add     = 1,
-        Disable = 2,
-        Enable  = 3,
+        Remove,
+        Add,
+        Disable,
+        Enable
     };
 
     void optModifyRepo(enum Actions action, QStringList opt);
diff --git a/ssuconfperm/ssuconfperm.c b/ssuconfperm/ssuconfperm.c
index 1442d36..c751e41 100644
--- a/ssuconfperm/ssuconfperm.c
+++ b/ssuconfperm/ssuconfperm.c
@@ -14,11 +14,12 @@
 
 #include "../constants.h"
 
-int main(int argc, char **argv){
-  struct stat sb;
+int main(int argc, char **argv)
+{
+    struct stat sb;
 
-  if (!stat(SSU_CONFIGURATION, &sb)){
-    chown(SSU_CONFIGURATION, 0, SSU_GROUP_ID);
-    chmod(SSU_CONFIGURATION, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH);
-  }
+    if (!stat(SSU_CONFIGURATION, &sb)){
+        chown(SSU_CONFIGURATION, 0, SSU_GROUP_ID);
+        chmod(SSU_CONFIGURATION, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH);
+    }
 }
diff --git a/ssud/ssud.cpp b/ssud/ssud.cpp
index fc9d8fa..1e410a6 100644
--- a/ssud/ssud.cpp
+++ b/ssud/ssud.cpp
@@ -16,7 +16,8 @@
 const char *Ssud::SERVICE_NAME = "org.nemo.ssu";
 const char *Ssud::OBJECT_PATH = "/org/nemo/ssu";
 
-Ssud::Ssud(QObject *parent): QObject(parent)
+Ssud::Ssud(QObject *parent)
+    : QObject(parent)
 {
     QDBusConnection connection = QDBusConnection::systemBus();
     if (!connection.registerObject(OBJECT_PATH, this)) {
diff --git a/ssuks/ssukickstarter.cpp b/ssuks/ssukickstarter.cpp
index 08b1f92..37fee75 100644
--- a/ssuks/ssukickstarter.cpp
+++ b/ssuks/ssukickstarter.cpp
@@ -64,13 +64,13 @@ QStringList SsuKickstarter::commandSection(const QString &section, const QString
                           .arg(SSU_DATA_DIR)
                           .arg(section)));
 
-    if (dir.exists(replaceSpaces(deviceModel.toLower())))
+    if (dir.exists(replaceSpaces(deviceModel.toLower()))) {
         commandFile = replaceSpaces(deviceModel.toLower());
-    else if (dir.exists(replaceSpaces(deviceInfo.deviceVariant(true).toLower())))
+    } else if (dir.exists(replaceSpaces(deviceInfo.deviceVariant(true).toLower()))) {
         commandFile = replaceSpaces(deviceInfo.deviceVariant(true).toLower());
-    else if (dir.exists("default"))
+    } else if (dir.exists("default")) {
         commandFile = "default";
-    else {
+    } else {
         if (description.isEmpty())
             result.append("## No suitable configuration found in " + dir.path());
         else
@@ -112,7 +112,7 @@ QStringList SsuKickstarter::repos()
     foreach (const QString &repo, repos) {
         QString repoUrl = ssu.repoUrl(repo, rndMode, QHash<QString, QString>(), repoOverride);
 
-        if (repoUrl == "") {
+        if (repoUrl.isEmpty()) {
             qerr << "Repository " << repo << " does not have an URL, ignoring" << endl;
             continue;
         }
@@ -124,26 +124,27 @@ QStringList SsuKickstarter::repos()
                           .arg(repo)
                           .arg(replaceSpaces(deviceModel))
                           .arg((rndMode ? repoOverride.value("rndRelease")
-                                : repoOverride.value("release")))
+                                        : repoOverride.value("release")))
                           .arg((rndMode ? "-" + repoOverride.value("flavourName")
-                                : ""))
+                                        : QString()))
                           .arg(repoUrl)
                          );
-        } else
+        } else {
             result.append(QString("repo --name=%1-%2%3 --baseurl=%4")
                           .arg(repo)
                           .arg((rndMode ? repoOverride.value("rndRelease")
-                                : repoOverride.value("release")))
+                                        : repoOverride.value("release")))
                           .arg((rndMode ? "-" + repoOverride.value("flavourName")
-                                : ""))
+                                        : QString()))
                           .arg(repoUrl)
                          );
+        }
     }
 
     return result;
 }
 
-QStringList SsuKickstarter::packagesSection(QString name)
+QStringList SsuKickstarter::packagesSection(const QString &name)
 {
     QStringList result;
 
@@ -166,7 +167,7 @@ QStringList SsuKickstarter::packagesSection(QString name)
 }
 
 // we intentionally don't support device-specific post scriptlets
-QStringList SsuKickstarter::scriptletSection(QString name, int flags)
+QStringList SsuKickstarter::scriptletSection(const QString &name, int flags)
 {
     QStringList result;
     QString path;
@@ -226,14 +227,9 @@ void SsuKickstarter::setRepoParameters(QHash<QString, QString> parameters)
         deviceModel = repoOverride.value("model");
 }
 
-bool SsuKickstarter::write(QString kickstart)
+bool SsuKickstarter::write(const QString &kickstart)
 {
-    QFile ks;
-    QTextStream kout;
     QTextStream qerr(stderr);
-    SsuDeviceInfo deviceInfo(deviceModel);
-    SsuRepoManager repoManager;
-    SsuVariables var;
     QStringList commandSections;
 
     // initialize with default 'part' for compatibility, as partitions
@@ -252,9 +248,11 @@ bool SsuKickstarter::write(QString kickstart)
     QHash<QString, QString> defaults;
     // get generic repo variables; domain and adaptation specific bits are not interesting
     // in the kickstart
+    SsuRepoManager repoManager;
     repoManager.repoVariables(&defaults, rndMode);
 
     // overwrite with kickstart defaults
+    SsuDeviceInfo deviceInfo(deviceModel);
     deviceInfo.variableSection("kickstart-defaults", &defaults);
     if (deviceInfo.variable("kickstart-defaults", "commandSections")
             .canConvert(QMetaType::QStringList)) {
@@ -308,7 +306,11 @@ bool SsuKickstarter::write(QString kickstart)
     QString outputDir = repoOverride.value("outputdir");
     if (!outputDir.isEmpty()) outputDir.append("/");
 
+    QFile ks;
+
     if (kickstart.isEmpty()) {
+        SsuVariables var;
+
         if (repoOverride.contains("filename")) {
             QString fileName = QString("%1%2")
                                .arg(outputDir)
@@ -321,9 +323,9 @@ bool SsuKickstarter::write(QString kickstart)
             qerr << "No filename specified, and no default filename configured" << endl;
             return false;
         }
-    } else if (kickstart == "-")
+    } else if (kickstart == "-") {
         opened = ks.open(stdout, QIODevice::WriteOnly);
-    else {
+    } else {
         ks.setFileName(outputDir + kickstart);
         opened = ks.open(QIODevice::WriteOnly);
     }
@@ -331,8 +333,9 @@ bool SsuKickstarter::write(QString kickstart)
     if (!opened) {
         qerr << "Unable to write output file " << ks.fileName() << ": " << ks.errorString() << endl;
         return false;
-    } else if (!ks.fileName().isEmpty())
+    } else if (!ks.fileName().isEmpty()) {
         qerr << "Writing kickstart to " << ks.fileName() << endl;
+    }
 
     QString displayName = QString("# DisplayName: %1 %2/%3 (%4) %5")
                           .arg(repoOverride.value("brand"))
@@ -365,6 +368,7 @@ bool SsuKickstarter::write(QString kickstart)
     QString kickstartType = QString("# KickstartType: %1")
                             .arg((rndMode ? "rnd" : "release"));
 
+    QTextStream kout;
     kout.setDevice(&ks);
     kout << displayName << endl;
     kout << kickstartType << endl;
diff --git a/ssuks/ssukickstarter.h b/ssuks/ssukickstarter.h
index 8233303..09bfde9 100644
--- a/ssuks/ssukickstarter.h
+++ b/ssuks/ssukickstarter.h
@@ -20,7 +20,7 @@ class SsuKickstarter
 public:
     SsuKickstarter();
     void setRepoParameters(QHash<QString, QString> parameters);
-    bool write(QString kickstart = "");
+    bool write(const QString &kickstart = QString());
 
     enum ScriptletFlags {
         /// Chroot is not useful, but helps in making the code more readable
@@ -36,11 +36,11 @@ class SsuKickstarter
     QString deviceModel;
     QStringList commands();
     /// read a command section from file system
-    QStringList commandSection(const QString &section, const QString &description = "");
-    QStringList packagesSection(QString name);
+    QStringList commandSection(const QString &section, const QString &description = QString());
+    QStringList packagesSection(const QString &name);
     QString replaceSpaces(const QString &value);
     QStringList repos();
-    QStringList scriptletSection(QString name, int flags = Chroot);
+    QStringList scriptletSection(const QString &name, int flags = Chroot);
 };
 
 #endif
diff --git a/ssuurlresolver/ssuurlresolver.cpp b/ssuurlresolver/ssuurlresolver.cpp
index 7b77283..e2f55f8 100644
--- a/ssuurlresolver/ssuurlresolver.cpp
+++ b/ssuurlresolver/ssuurlresolver.cpp
@@ -16,14 +16,15 @@
 #include "libssu/sandbox_p.h"
 #include "libssu/ssulog_p.h"
 
-SsuUrlResolver::SsuUrlResolver(): QObject()
+SsuUrlResolver::SsuUrlResolver()
+    : QObject()
 {
     QObject::connect(this, SIGNAL(done()),
                      QCoreApplication::instance(), SLOT(quit()),
                      Qt::QueuedConnection);
 }
 
-void SsuUrlResolver::error(QString message)
+void SsuUrlResolver::error(const QString &message)
 {
     SsuLog *ssuLog = SsuLog::instance();
     ssuLog->print(LOG_WARNING, message);
@@ -34,7 +35,7 @@ void SsuUrlResolver::error(QString message)
     QCoreApplication::exit(1);
 }
 
-bool SsuUrlResolver::writeZyppCredentialsIfNeeded(QString credentialsScope)
+bool SsuUrlResolver::writeZyppCredentialsIfNeeded(const QString &credentialsScope)
 {
     QString filePath = Sandbox::map("/etc/zypp/credentials.d/" + credentialsScope);
     QFileInfo credentialsFileInfo(filePath);
@@ -52,7 +53,7 @@ bool SsuUrlResolver::writeZyppCredentialsIfNeeded(QString credentialsScope)
     QPair<QString, QString> credentials = ssu.credentials(credentialsScope);
     SsuLog *ssuLog = SsuLog::instance();
 
-    if (credentials.first == "" || credentials.second == "") {
+    if (credentials.first.isEmpty() || credentials.second.isEmpty()) {
         ssuLog->print(LOG_WARNING, "Returned credentials are empty, skip writing");
         return false;
     }
@@ -74,7 +75,7 @@ bool SsuUrlResolver::writeZyppCredentialsIfNeeded(QString credentialsScope)
 void SsuUrlResolver::run()
 {
     QHash<QString, QString> repoParameters;
-    QString resolvedUrl, repo;
+    QString repo;
     bool isRnd = false;
     SsuLog *ssuLog = SsuLog::instance();
 
@@ -130,11 +131,12 @@ void SsuUrlResolver::run()
         if (ssu.error()) {
             error(ssu.lastError());
         }
-    } else
+    } else {
         ssuLog->print(LOG_DEBUG, "Device not registered -- skipping credential update");
+    }
 
     // resolve base url
-    resolvedUrl = ssu.repoUrl(repo, isRnd, repoParameters);
+    QString resolvedUrl = ssu.repoUrl(repo, isRnd, repoParameters);
 
     QString credentialsScope = ssu.credentialsScope(repo, isRnd);
     // only do credentials magic on secure connections
@@ -155,8 +157,9 @@ void SsuUrlResolver::run()
         }
         headerList.append(QString("credentials=%1").arg(credentialsScope));
         writeZyppCredentialsIfNeeded(credentialsScope);
-    } else
+    } else {
         ssuLog->print(LOG_DEBUG, QString("Skipping credential for %1 with scope %2").arg(repo).arg(credentialsScope));
+    }
 
     if (!headerList.isEmpty() && !resolvedUrl.isEmpty()) {
         QUrl url(resolvedUrl);
diff --git a/ssuurlresolver/ssuurlresolver.h b/ssuurlresolver/ssuurlresolver.h
index c904664..fee5f96 100644
--- a/ssuurlresolver/ssuurlresolver.h
+++ b/ssuurlresolver/ssuurlresolver.h
@@ -58,9 +58,8 @@ class SsuUrlResolver: public QObject
 
 private:
     Ssu ssu;
-    void error(QString message);
-    void printJournal(int priority, QString message);
-    bool writeZyppCredentialsIfNeeded(QString credentialsScope);
+    void error(const QString &message);
+    bool writeZyppCredentialsIfNeeded(const QString &credentialsScope);
 
 public slots:
     void run();