diff --git a/src/config/preferences-generator.py b/src/config/preferences-generator.py
index bc868a9a..cabdc8f8 100644
--- a/src/config/preferences-generator.py
+++ b/src/config/preferences-generator.py
@@ -1,504 +1,504 @@
 ###########################################################################
 #   Copyright (C) 2019 by Thomas Fischer <fischer@unix-ag.uni-kl.de>      #
 #                                                                         #
 #   This script is free software; you can redistribute it and/or modify   #
 #   it under the terms of the GNU General Public License as published by  #
 #   the Free Software Foundation; either version 2 of the License, or     #
 #   (at your option) any later version.                                   #
 #                                                                         #
 #   This script is distributed in the hope that it will be useful,        #
 #   but WITHOUT ANY WARRANTY; without even the implied warranty of        #
 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         #
 #   GNU General Public License for more details.                          #
 #                                                                         #
 #   You should have received a copy of the GNU General Public License     #
 #   along with this script; if not, see <https://www.gnu.org/licenses/>.  #
 ###########################################################################
 
 import sys
 import json
 import datetime
 
 
 def print_copyright_header(outputdevice=sys.stdout):
     """Print the default copyright statement to the output device."""
 
     print("""/***************************************************************************
  *   Copyright (C) 2004-{year} by Thomas Fischer <fischer@unix-ag.uni-kl.de> *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 2 of the License, or     *
  *   (at your option) any later version.                                   *
  *                                                                         *
  *   This program is distributed in the hope that it will be useful,       *
  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  *   GNU General Public License for more details.                          *
  *                                                                         *
  *   You should have received a copy of the GNU General Public License     *
  *   along with this program; if not, see <https://www.gnu.org/licenses/>. *
  ***************************************************************************/"""
           .format(year=datetime.date.today().year), file=outputdevice)
     print(file=outputdevice)
     print("""/// This file has been automatically generated using the script 'preferences-generator.py'
 /// based on configuration data from file 'preferences.json'. If there are any problems or
 /// bugs, you need to fix those two files and re-generated both 'preferences.h' and
 /// 'preferences.cpp'. Manual changes in this file will be overwritten the next time the
 /// script will be run. You have been warned.""", file=outputdevice)
     print(file=outputdevice)
 
 
 def needsReference(type):
     """Check if given Qt/C++ data type should be passed by reference rather than by value."""
     return type in ["QString", "QStringList"] \
         or type.startswith(('QPair<', 'QVector<', 'QSet<', 'QList<', 'QLinkedList<', 'QMap<', 'QVector<', 'QHash<'))
 
 
 def print_header(headerincludes, implementationincludes, enums, settings, outputdevice=sys.stdout):
     """Print the header file for the Preferences ('preferences.h')."""
 
     print_copyright_header(outputdevice)
 
     # Include guard definition
     print("#ifndef KBIBTEX_CONFIG_PREFERENCES_H", file=outputdevice)
     print("#define KBIBTEX_CONFIG_PREFERENCES_H", file=outputdevice)
     print(file=outputdevice)
 
     # Include other headers as necessary
     for includeline in headerincludes:
         if len(includeline) == 0:
             print(file=outputdevice)
         elif includeline[0] == '#':
             print(includeline, file=outputdevice)
         else:
             print("#include", includeline, file=outputdevice)
     if headerincludes:
         print(file=outputdevice)
     print('#ifdef HAVE_KF5', file=outputdevice)
     print('#include "kbibtexconfig_export.h"', file=outputdevice)
     print('#endif // HAVE_KF5', file=outputdevice)
     print(file=outputdevice)
 
     print("class KBIBTEXCONFIG_EXPORT Preferences {", file=outputdevice)
     print("public:", file=outputdevice)
     print("    static Preferences &instance();", file=outputdevice)
     print("    ~Preferences();", file=outputdevice)
     print(file=outputdevice)
 
     for enum in sorted(enums):
         print("    enum " + enum + " {", end="", file=outputdevice)
         first = True
         for enumvaluepair in enums[enum]:
             if not first:
                 print(",", end="", file=outputdevice)
             print(" ", end="", file=outputdevice)
             if isinstance(enumvaluepair, list):
                 print(enumvaluepair[0], end="", file=outputdevice)
                 if len(enumvaluepair) >= 2 and enumvaluepair[1] != None:
                     print(
                         " = " + str(enumvaluepair[1]), end="", file=outputdevice)
             elif isinstance(enumvaluepair, str):
                 print(enumvaluepair, end="", file=outputdevice)
             first = False
         print(" };", file=outputdevice)
     if enums:
         print(file=outputdevice)
 
     for setting in settings:
         stem = setting['stem']
         type = setting['type']
         lowercasestart = stem[0].lower() + stem[1:]
         print(file=outputdevice)
         print("    /// ***", stem, "of type", type, "***", file=outputdevice)
         print(file=outputdevice)
         if 'predefined' in setting:
             for predefined in setting['predefined']:
                 print("    static const " + type + " " +
                       lowercasestart + predefined[0] + ";", file=outputdevice)
         print("    static const " +
               type + " default" + stem + ";", file=outputdevice)
         if 'availabletype' in setting:
             print("    static const " +
                   setting['availabletype'] + " available" + stem + "s;", file=outputdevice)
         print(("    const " if needsReference(type) else "    ") + type + (" &" if needsReference(type) else " ") +
               lowercasestart + "();", file=outputdevice)
         print('#ifdef HAVE_KF5', file=outputdevice)
         print('    /*!', file=outputdevice)
         print('     * @return true if this setting has been changed, i.e. the new value was different from the old value; false otherwise or under error conditions', file=outputdevice)
         print('     */', file=outputdevice)
         print("    bool set" + stem + "(const " +
               type + (" &" if needsReference(type) else " ") + lowercasestart + ");", file=outputdevice)
         print('#endif // HAVE_KF5', file=outputdevice)
         print("", file=outputdevice)
 
     print("private:", file=outputdevice)
     print("    Q_DISABLE_COPY(Preferences)", file=outputdevice)
     print(file=outputdevice)
     print("    explicit Preferences();", file=outputdevice)
     print(file=outputdevice)
     print("    class Private;", file=outputdevice)
     print("    Private *const d;", file=outputdevice)
     print("};", file=outputdevice)
     print(file=outputdevice)
     print("#endif // KBIBTEX_CONFIG_PREFERENCES_H", file=outputdevice)
 
 
 def print_implementation(headerincludes, implementationincludes, enums, settings, outputdevice=sys.stdout):
     """Print the implementatiom file for the Preferences ('preferences.cpp')."""
 
     print_copyright_header(outputdevice)
 
     # Include headers that will always be necessary
     print('#include <Preferences>', file=outputdevice)
     print(file=outputdevice)
     print('#include <QCoreApplication>', file=outputdevice)
     print('#ifdef HAVE_KF5', file=outputdevice)
     print('#include <KLocalizedString>', file=outputdevice)
     print('#include <KSharedConfig>', file=outputdevice)
     print('#include <KConfigWatcher>', file=outputdevice)
     print('#include <KConfigGroup>', file=outputdevice)
     print('#else // HAVE_KF5', file=outputdevice)
     print('#define i18n(text) QStringLiteral(text)', file=outputdevice)
     print('#define i18nc(comment,text) QStringLiteral(text)', file=outputdevice)
     print('#endif // HAVE_KF5', file=outputdevice)
     print(file=outputdevice)
     print('#ifdef HAVE_KF5', file=outputdevice)
     print('#include <NotificationHub>', file=outputdevice)
     print('#endif // HAVE_KF5', file=outputdevice)
     print(file=outputdevice)
     # Include other headers as necessary
     for includeline in implementationincludes:
         if len(includeline) == 0:
             print(file=outputdevice)
         elif includeline[0] == '#':
             print(includeline, file=outputdevice)
         else:
             print("#include", includeline, file=outputdevice)
     if implementationincludes:
         print(file=outputdevice)
     print('class Preferences::Private', file=outputdevice)
     print('{', file=outputdevice)
     print('public:', file=outputdevice)
     print('#ifdef HAVE_KF5', file=outputdevice)
     print('    KSharedConfigPtr config;', file=outputdevice)
     print('    KConfigWatcher::Ptr watcher;', file=outputdevice)
     print(file=outputdevice)
     for setting in settings:
         stem = setting['stem']
         type = setting['type']
         if type in enums:
             type = "Preferences::" + type
         print('    bool dirtyFlag' + stem + ';', file=outputdevice)
         print('    ' + type + ' cached' + stem + ';', file=outputdevice)
     print('#endif // HAVE_KF5', file=outputdevice)
 
     # Constructor for Preferences::Private
     print(file=outputdevice)
     print('    Private(Preferences *)', file=outputdevice)
     print('    {', file=outputdevice)
     print('#ifdef HAVE_KF5', file=outputdevice)
     print('        config = KSharedConfig::openConfig(QStringLiteral("kbibtexrc"));', file=outputdevice)
     print('        watcher = KConfigWatcher::create(config);', file=outputdevice)
     for setting in settings:
         stem = setting['stem']
         print('        dirtyFlag' + stem + ' = true;', file=outputdevice)
         print('        cached' + stem + ' = Preferences::default' +
               stem + ';', file=outputdevice)
     print('#endif // HAVE_KF5', file=outputdevice)
     print('    }', file=outputdevice)
 
     print(file=outputdevice)
     print('#ifdef HAVE_KF5', file=outputdevice)
     first = True
     for setting in settings:
         stem = setting['stem']
         type = setting['type']
         if type in enums:
             type = "Preferences::" + type
         if first:
             first = False
         else:
             print(file=outputdevice)
         print('    inline bool validateValueFor' + stem + '(const ' + type +
               (" &" if needsReference(type) else " ") + "valueToBeChecked) {", file=outputdevice)
         if 'validationcode' in setting:
             if isinstance(setting['validationcode'], list):
                 for line in setting['validationcode']:
                     print('        ' + line, file=outputdevice)
                 if not setting['validationcode'][-1].startswith("return "):
                     print('        return false;', file=outputdevice)
             elif isinstance(setting['validationcode'], str):
                 print('        ' +
                       setting['validationcode'], file=outputdevice)
         elif 'availabletype' in setting and setting['availabletype'].startswith('QVector<QPair<' + type + ","):
             print('        for (' + setting['availabletype'] + '::ConstIterator it = Preferences::available' + stem +
                   's.constBegin(); it != Preferences::available' + stem + 's.constEnd(); ++it)', file=outputdevice)
             print(
                 '            if (it->first == valueToBeChecked) return true;', file=outputdevice)
             print('        return false;', file=outputdevice)
         elif 'availabletype' in setting and setting['availabletype'] == "QStringList":
             print('        return Preferences::available' + stem +
                   's.contains(valueToBeChecked);', file=outputdevice)
         else:
             print('        Q_UNUSED(valueToBeChecked)', file=outputdevice)
             print('        return true;', file=outputdevice)
         print('    }', file=outputdevice)
 
         if 'readEntry' in setting:
             print(file=outputdevice)
             print('    ' + type + ' readEntry' + stem +
                   '(const KConfigGroup &configGroup, const QString &key) const', file=outputdevice)
             print('    {', file=outputdevice)
             if isinstance(setting['readEntry'], list):
                 for line in setting['readEntry']:
                     print('        ' + line, file=outputdevice)
             elif isinstance(setting['readEntry'], str):
                 print('        ' + setting['readEntry'], file=outputdevice)
             print('    }', file=outputdevice)
 
         if 'writeEntry' in setting:
             print(file=outputdevice)
             print('    void writeEntry' + stem + '(KConfigGroup &configGroup, const QString &key, const ' +
                   type + (" &" if needsReference(type) else " ") + 'valueToBeWritten)', file=outputdevice)
             print('    {', file=outputdevice)
             if isinstance(setting['writeEntry'], list):
                 for line in setting['writeEntry']:
                     print('        ' + line, file=outputdevice)
             elif isinstance(setting['writeEntry'], str):
                 print('        ' + setting['writeEntry'], file=outputdevice)
             print('    }', file=outputdevice)
     print('#endif // HAVE_KF5', file=outputdevice)
     print('};', file=outputdevice)
 
     # Singleton function Preferences::instance()
     print(file=outputdevice)
     print('Preferences &Preferences::instance()', file=outputdevice)
     print('{', file=outputdevice)
     print('    static Preferences singleton;', file=outputdevice)
     print('    return singleton;', file=outputdevice)
     print('}', file=outputdevice)
     print(file=outputdevice)
     # Constructor for class Preferences
     print('Preferences::Preferences()', file=outputdevice)
     print('        : d(new Preferences::Private(this))', file=outputdevice)
     print('{', file=outputdevice)
     print('#ifdef HAVE_KF5', file=outputdevice)
     print(
         '    QObject::connect(d->watcher.data(), &KConfigWatcher::configChanged, QCoreApplication::instance(), [this](const KConfigGroup &group, const QByteArrayList &names) {', file=outputdevice)
     print('        QSet<int> eventsToPublish;', file=outputdevice)
     for setting in settings:
         stem = setting['stem']
         configgroup = setting['configgroup'] if 'configgroup' in setting else 'General'
         print('        if (group.name() == QStringLiteral("' + configgroup +
               '") && names.contains("' + stem + '")) {', file=outputdevice)
         print('            /// Configuration setting ' + stem +
               ' got changed by another Preferences instance";', file=outputdevice)
         print('            d->dirtyFlag' +
               stem + ' = true;', file=outputdevice)
         if 'notificationevent' in setting:
             print('            eventsToPublish.insert(' +
                   setting['notificationevent'] + ');', file=outputdevice)
         print('        }', file=outputdevice)
     print(file=outputdevice)
     print('        for (const int eventId : eventsToPublish)', file=outputdevice)
     print('            NotificationHub::publishEvent(eventId);', file=outputdevice)
     print('    });', file=outputdevice)
     print('#endif // HAVE_KF5', file=outputdevice)
     print('}', file=outputdevice)
     print(file=outputdevice)
     # Destructor for Preferences
     print('Preferences::~Preferences()', file=outputdevice)
     print('{', file=outputdevice)
     print('    delete d;', file=outputdevice)
     print('}', file=outputdevice)
 
     for setting in settings:
         stem = setting['stem']
         configgroup = setting['configgroup'] if 'configgroup' in setting else 'General'
-        type = type = setting['type']
+        type = setting['type']
         typeInConfig = "int" if type in enums.keys() else type
         if 'podtype' in setting:
             typeInConfig = setting['podtype']
         if type in enums:
             type = "Preferences::" + type
         lowercasestart = stem[0].lower() + stem[1:]
 
         print(file=outputdevice)
 
         if 'predefined' in setting:
             for predefined in setting['predefined']:
                 print('const ' + type + ' Preferences::' + lowercasestart +
                       predefined[0] + " = " + predefined[1] + ";", file=outputdevice)
 
         if 'available' in setting:
             available = setting['available']
             print('const ' + setting['availabletype'] + ' Preferences::available' + stem +
                   ('s ' if available.startswith("{") else "s = ") + available + ";", file=outputdevice)
 
         default = "nullptr"
         if 'default' in setting:
             default = setting['default']
             if 'predefined' in setting and default in [pair[0] for pair in setting['predefined']]:
                 default = "Preferences::" + lowercasestart + default
         elif 'availabletype' in setting:
             if setting['availabletype'].startswith("QVector<QPair<"):
                 default = 'Preferences::available' + stem + 's.front().first'
             elif setting['availabletype'] == "QStringList":
                 default = 'Preferences::available' + stem + 's.front()'
         print('const ' + type + ' Preferences::default' + stem +
               (' ' if default.startswith("{") else " = ") + default + ";", file=outputdevice)
 
         print(file=outputdevice)
 
         print(("const " if needsReference(type) else "") + type + (" &" if needsReference(type) else " ") +
               "Preferences::" + lowercasestart + "()", file=outputdevice)
         print("{", file=outputdevice)
         print('#ifdef HAVE_KF5', file=outputdevice)
         print('    if (d->dirtyFlag' + stem + ') {', file=outputdevice)
         print('        d->config->reparseConfiguration();', file=outputdevice)
         print('        static const KConfigGroup configGroup(d->config, QStringLiteral("' +
               configgroup + '"));', file=outputdevice)
         print('        const ' + type +
               ' valueFromConfig = ', end="", file=outputdevice)
         if 'readEntry' in setting:
             print('d->readEntry' + stem + '(configGroup, QStringLiteral("' +
                   stem + '"));', file=outputdevice)
         else:
             if typeInConfig != type:
                 print('static_cast<' + type + '>(', end="", file=outputdevice)
             print('configGroup.readEntry(QStringLiteral("' +
                   stem + '"), ', end="", file=outputdevice)
             if typeInConfig != type:
                 print('static_cast<' + typeInConfig +
                       '>(', end="", file=outputdevice)
             print('Preferences::default' + stem, end="", file=outputdevice)
             if typeInConfig != type:
                 print(')', end="", file=outputdevice)
             print(')', end="", file=outputdevice)
             if typeInConfig != type:
                 print(')', end="", file=outputdevice)
             print(';', file=outputdevice)
         print('        if (d->validateValueFor' + stem +
               '(valueFromConfig)) {', file=outputdevice)
         print('            d->cached' + stem +
               ' = valueFromConfig;', file=outputdevice)
         print('            d->dirtyFlag' +
               stem + ' = false;', file=outputdevice)
         print('        } else {', file=outputdevice)
         print('            /// Configuration file setting for ' + stem +
               ' has an invalid value, using default as fallback', file=outputdevice)
         print('            set' + stem +
               '(Preferences::default' + stem + ');', file=outputdevice)
         print('        }', file=outputdevice)
         print('    }', file=outputdevice)
         print('    return d->cached' + stem + ";", file=outputdevice)
         print('#else // HAVE_KF5', file=outputdevice)
         print('    return default' + stem + ";", file=outputdevice)
         print('#endif // HAVE_KF5', file=outputdevice)
         print("}", file=outputdevice)
 
         print(file=outputdevice)
 
         print('#ifdef HAVE_KF5', file=outputdevice)
         print("bool Preferences::set" + stem + '(const ' + type +
               (" &" if needsReference(type) else " ") + 'newValue)', file=outputdevice)
         print("{", file=outputdevice)
 
         if 'sanitizecode' in setting:
             newValueVariable = 'sanitizedNewValue'
             if isinstance(setting['sanitizecode'], str):
                 print('    ' + setting['sanitizecode'], file=outputdevice)
             elif isinstance(setting['sanitizecode'], list):
                 for line in setting['sanitizecode']:
                     print('    ' + line, file=outputdevice)
             else:
                 newValueVariable = 'newValue'
         elif 'availabletype' in setting and setting['availabletype'] == 'QStringList':
             newValueVariable = 'sanitizedNewValue'
             print('    ' + type + ' sanitizedNewValue = newValue;',
                   file=outputdevice)
             print('    const ' + type +
                   ' lowerSanitizedNewValue = sanitizedNewValue.toLower();', file=outputdevice)
             print('    for (const QString &known' + stem +
                   ' : available' + stem + 's)', file=outputdevice)
             print('        if (known' + stem +
                   '.toLower() == lowerSanitizedNewValue) {', file=outputdevice)
             print('            sanitizedNewValue = known' +
                   stem + ';', file=outputdevice)
             print('            break;', file=outputdevice)
             print('        }', file=outputdevice)
         else:
             newValueVariable = 'newValue'
 
         print('    if (!d->validateValueFor' + stem +
               '(' + newValueVariable + ')) return false;', file=outputdevice)
         print('    d->dirtyFlag' + stem + ' = false;', file=outputdevice)
         print('    d->cached' + stem + ' = ' +
               newValueVariable + ';', file=outputdevice)
         print('    static KConfigGroup configGroup(d->config, QStringLiteral("' +
               configgroup + '"));', file=outputdevice)
         print('    const ' + type + ' valueFromConfig = ',
               end="", file=outputdevice)
         if 'readEntry' in setting:
             print('d->readEntry' + stem + '(configGroup, QStringLiteral("' +
                   stem + '"));', file=outputdevice)
         else:
             if typeInConfig != type:
                 print('static_cast<' + type + '>(', end="", file=outputdevice)
             print('configGroup.readEntry(QStringLiteral("' +
                   stem + '"), ', end="", file=outputdevice)
             if typeInConfig != type:
                 print('static_cast<' + typeInConfig +
                       '>(', end="", file=outputdevice)
             print('Preferences::default' + stem, end="", file=outputdevice)
             if typeInConfig != type:
                 print(')', end="", file=outputdevice)
             print(')', end="", file=outputdevice)
             if typeInConfig != type:
                 print(')', end="", file=outputdevice)
             print(';', file=outputdevice)
         print('    if (valueFromConfig == ' + newValueVariable +
               ') return false;', file=outputdevice)
         if 'writeEntry' in setting:
             print('    d->writeEntry' + stem + '(configGroup, QStringLiteral("' +
                   stem + '"), ' + newValueVariable + ');', file=outputdevice)
         else:
             print('    configGroup.writeEntry(QStringLiteral("' +
                   stem + '"), ', end="", file=outputdevice)
             if typeInConfig != type:
                 print('static_cast<' + typeInConfig +
                       '>(', end="", file=outputdevice)
             print(newValueVariable, end="", file=outputdevice)
             if typeInConfig != type:
                 print(')', end="", file=outputdevice)
             print(', KConfig::Notify);', file=outputdevice)
         print('    d->config->sync();', file=outputdevice)
         # NotificationHub::publishEvent(notificationEventId);
         print('    return true;', file=outputdevice)
         print("}", file=outputdevice)
         print('#endif // HAVE_KF5', file=outputdevice)
 
 
 jsondata = {}
 with open("preferences.json") as jsonfile:
     jsondata = json.load(jsonfile)
 headerincludes = jsondata['headerincludes'] \
     if 'headerincludes' in jsondata else {}
 implementationincludes = jsondata['implementationincludes'] \
     if 'implementationincludes' in jsondata else {}
 enums = jsondata['enums'] \
     if 'enums' in jsondata else {}
 settings = jsondata['settings'] \
     if 'settings' in jsondata else {}
 
 for setting in settings:
     if 'headerincludes' in setting:
         headerincludes.extend(setting['headerincludes'])
 
 with open("/tmp/preferences.h", "w") as headerfile:
     print_header(headerincludes, implementationincludes,
                  enums, settings, outputdevice=headerfile)
 with open("/tmp/preferences.cpp", "w") as implementationfile:
     print_implementation(headerincludes, implementationincludes,
                          enums, settings, outputdevice=implementationfile)