diff --git a/src/librssguard/core/feeddownloader.cpp b/src/librssguard/core/feeddownloader.cpp
index 5424fa59b..932a3ad89 100644
--- a/src/librssguard/core/feeddownloader.cpp
+++ b/src/librssguard/core/feeddownloader.cpp
@@ -226,7 +226,7 @@ void FeedDownloader::updateOneFeed(Feed* feed) {
       }
 
       // Process changed labels.
-      for (Label* lbl : msg_backup.m_assignedLabels) {
+      for (Label* lbl : qAsConst(msg_backup.m_assignedLabels)) {
         if (!msg_orig->m_assignedLabels.contains(lbl)) {
           // Label is not there anymore, it was deassigned.
           lbl->deassignFromMessage(*msg_orig);
@@ -238,7 +238,7 @@ void FeedDownloader::updateOneFeed(Feed* feed) {
         }
       }
 
-      for (Label* lbl : msg_orig->m_assignedLabels) {
+      for (Label* lbl : qAsConst(msg_orig->m_assignedLabels)) {
         if (!msg_backup.m_assignedLabels.contains(lbl)) {
           // Label is in new message, but is not in old message, it
           // was newly assigned.
diff --git a/src/librssguard/core/feedsmodel.cpp b/src/librssguard/core/feedsmodel.cpp
index 789eac837..25a5ea41c 100644
--- a/src/librssguard/core/feedsmodel.cpp
+++ b/src/librssguard/core/feedsmodel.cpp
@@ -3,9 +3,9 @@
 #include "core/feedsmodel.h"
 
 #include "3rd-party/boolinq/boolinq.h"
+#include "database/databasefactory.h"
 #include "definitions/definitions.h"
 #include "gui/dialogs/formmain.h"
-#include "database/databasefactory.h"
 #include "miscellaneous/feedreader.h"
 #include "miscellaneous/iconfactory.h"
 #include "miscellaneous/textfactory.h"
@@ -292,8 +292,9 @@ void FeedsModel::reassignNodeToNewParent(RootItem* original_node, RootItem* new_
 
 QList<ServiceRoot*>FeedsModel::serviceRoots() const {
   QList<ServiceRoot*> roots;
+  auto ch = m_rootItem->childItems();
 
-  for (RootItem* root : m_rootItem->childItems()) {
+  for (RootItem* root : qAsConst(ch)) {
     if (root->kind() == RootItem::Kind::ServiceRoot) {
       roots.append(root->toServiceRoot());
     }
@@ -304,8 +305,9 @@ QList<ServiceRoot*>FeedsModel::serviceRoots() const {
 
 QList<Feed*>FeedsModel::feedsForScheduledUpdate(bool auto_update_now) {
   QList<Feed*>feeds_for_update;
+  auto stf = m_rootItem->getSubTreeFeeds();
 
-  for (Feed* feed : m_rootItem->getSubTreeFeeds()) {
+  for (Feed* feed : qAsConst(stf)) {
     switch (feed->autoUpdateType()) {
       case Feed::AutoUpdateType::DontAutoUpdate:
 
@@ -489,8 +491,9 @@ bool FeedsModel::addServiceAccount(ServiceRoot* root, bool freshly_activated) {
 
 bool FeedsModel::restoreAllBins() {
   bool result = true;
+  auto srts = serviceRoots();
 
-  for (ServiceRoot* root : serviceRoots()) {
+  for (ServiceRoot* root : qAsConst(srts)) {
     RecycleBin* bin_of_root = root->recycleBin();
 
     if (bin_of_root != nullptr) {
@@ -503,8 +506,9 @@ bool FeedsModel::restoreAllBins() {
 
 bool FeedsModel::emptyAllBins() {
   bool result = true;
+  auto srts = serviceRoots();
 
-  for (ServiceRoot* root : serviceRoots()) {
+  for (ServiceRoot* root : qAsConst(srts)) {
     RecycleBin* bin_of_root = root->recycleBin();
 
     if (bin_of_root != nullptr) {
@@ -516,8 +520,10 @@ bool FeedsModel::emptyAllBins() {
 }
 
 void FeedsModel::loadActivatedServiceAccounts() {
+  auto serv = qApp->feedReader()->feedServices();
+
   // Iterate all globally available feed "service plugins".
-  for (const ServiceEntryPoint* entry_point : qApp->feedReader()->feedServices()) {
+  for (const ServiceEntryPoint* entry_point : qAsConst(serv)) {
     // Load all stored root nodes from the entry point and add those to the model.
     QList<ServiceRoot*> roots = entry_point->initializeSubtree();
 
@@ -534,7 +540,9 @@ void FeedsModel::loadActivatedServiceAccounts() {
 }
 
 void FeedsModel::stopServiceAccounts() {
-  for (ServiceRoot* account : serviceRoots()) {
+  auto serv = serviceRoots();
+
+  for (ServiceRoot* account : qAsConst(serv)) {
     account->stop();
   }
 }
diff --git a/src/librssguard/core/message.cpp b/src/librssguard/core/message.cpp
index 66da7a477..078da16ba 100644
--- a/src/librssguard/core/message.cpp
+++ b/src/librssguard/core/message.cpp
@@ -20,13 +20,14 @@ Enclosure::Enclosure(QString url, QString mime) : m_url(std::move(url)), m_mimeT
 
 QList<Enclosure> Enclosures::decodeEnclosuresFromString(const QString& enclosures_data) {
   QList<Enclosure> enclosures;
-
-  for (const QString& single_enclosure : enclosures_data.split(ENCLOSURES_OUTER_SEPARATOR,
+  auto enc = enclosures_data.split(ENCLOSURES_OUTER_SEPARATOR,
 #if QT_VERSION >= 0x050F00 // Qt >= 5.15.0
-                                                               Qt::SplitBehaviorFlags::SkipEmptyParts)) {
+                                   Qt::SplitBehaviorFlags::SkipEmptyParts);
 #else
-                                                               QString::SplitBehavior::SkipEmptyParts)) {
+                                   QString::SplitBehavior::SkipEmptyParts);
 #endif
+
+  for (const QString& single_enclosure : qAsConst(enc)) {
     Enclosure enclosure;
 
     if (single_enclosure.contains(ECNLOSURES_INNER_SEPARATOR)) {
diff --git a/src/librssguard/core/messageobject.cpp b/src/librssguard/core/messageobject.cpp
index f999c9fb2..0f3b19ee2 100755
--- a/src/librssguard/core/messageobject.cpp
+++ b/src/librssguard/core/messageobject.cpp
@@ -22,7 +22,7 @@ bool MessageObject::isDuplicateWithAttribute(MessageObject::DuplicationAttribute
   // Check database according to duplication attribute_check.
   QSqlQuery q(*m_db);
   QStringList where_clauses;
-  QList<QPair<QString, QVariant>> bind_values;
+  QVector<QPair<QString, QVariant>> bind_values;
 
   // Now we construct the query according to parameter.
   if ((attribute_check& DuplicationAttributeCheck::SameTitle) == DuplicationAttributeCheck::SameTitle) {
diff --git a/src/librssguard/core/messageobject.h b/src/librssguard/core/messageobject.h
index 7cf18c6a4..36ea5e543 100755
--- a/src/librssguard/core/messageobject.h
+++ b/src/librssguard/core/messageobject.h
@@ -70,7 +70,7 @@ class MessageObject : public QObject {
     // Check if message is duplicate with another messages in DB.
     // Parameter "attribute_check" is DuplicationAttributeCheck enum
     // value casted to int.
-    Q_INVOKABLE bool isDuplicateWithAttribute(DuplicationAttributeCheck attribute_check) const;
+    Q_INVOKABLE bool isDuplicateWithAttribute(MessageObject::DuplicationAttributeCheck attribute_check) const;
 
     // Adds given label to list of assigned labels to this message.
     // Returns true if label was assigned now or if the message already has it assigned.
diff --git a/src/librssguard/database/databasefactory.cpp b/src/librssguard/database/databasefactory.cpp
index 3d358606a..8e7b505e8 100644
--- a/src/librssguard/database/databasefactory.cpp
+++ b/src/librssguard/database/databasefactory.cpp
@@ -48,7 +48,7 @@ void DatabaseFactory::determineDriver() {
   if (m_dbDriver->driverType() != DatabaseDriver::DriverType::SQLite) {
     // Try to setup connection and fallback to SQLite.
     try {
-      m_dbDriver->connection(metaObject()->className());
+      m_dbDriver->connection(QSL("DatabaseFactory"));
     }
     catch (const ApplicationException& ex) {
       qCriticalNN << LOGSEC_DB
diff --git a/src/librssguard/database/databasequeries.cpp b/src/librssguard/database/databasequeries.cpp
index 513117a4b..4dc8d3a95 100755
--- a/src/librssguard/database/databasequeries.cpp
+++ b/src/librssguard/database/databasequeries.cpp
@@ -598,8 +598,6 @@ int DatabaseQueries::getMessageCountsForLabel(const QSqlDatabase& db, Label* lab
     return q.value(0).toInt();
   }
   else {
-    auto aa = q.lastError().text();
-
     if (ok != nullptr) {
       *ok = false;
     }
@@ -877,8 +875,6 @@ QList<Message> DatabaseQueries::getUndeletedMessagesForAccount(const QSqlDatabas
     }
   }
   else {
-    auto aa = q.lastError().text();
-
     if (ok != nullptr) {
       *ok = false;
     }
@@ -1268,7 +1264,7 @@ bool DatabaseQueries::deleteAccount(const QSqlDatabase& db, int account_id) {
           << QSL("DELETE FROM Labels WHERE account_id = :account_id;")
           << QSL("DELETE FROM Accounts WHERE id = :account_id;");
 
-  for (const QString& q : queries) {
+  for (const QString& q : qAsConst(queries)) {
     query.prepare(q);
     query.bindValue(QSL(":account_id"), account_id);
 
@@ -1483,8 +1479,6 @@ bool DatabaseQueries::purgeLeftoverLabelAssignments(const QSqlDatabase& db, int
   }
 
   if (!succ) {
-    auto xx = q.lastError().text();
-
     qWarningNN << LOGSEC_DB
                << "Removing of leftover label assignments failed: '"
                << q.lastError().text()
@@ -1509,11 +1503,10 @@ bool DatabaseQueries::purgeLabelsAndLabelAssignments(const QSqlDatabase& db, int
 }
 
 bool DatabaseQueries::storeAccountTree(const QSqlDatabase& db, RootItem* tree_root, int account_id) {
-  QSqlQuery query_category(db);
-  QSqlQuery query_feed(db);
-
   // Iterate all children.
-  for (RootItem* child : tree_root->getSubTree()) {
+  auto str = tree_root->getSubTree();
+
+  for (RootItem* child : qAsConst(str)) {
     if (child->kind() == RootItem::Kind::Category) {
       createOverwriteCategory(db, child->toCategory(), account_id, child->parent()->id());
     }
@@ -1522,7 +1515,9 @@ bool DatabaseQueries::storeAccountTree(const QSqlDatabase& db, RootItem* tree_ro
     }
     else if (child->kind() == RootItem::Kind::Labels) {
       // Add all labels.
-      for (RootItem* lbl : child->childItems()) {
+      auto ch = child->childItems();
+
+      for (RootItem* lbl : qAsConst(ch)) {
         Label* label = lbl->toLabel();
 
         if (!createLabel(db, label, account_id)) {
@@ -1733,8 +1728,6 @@ void DatabaseQueries::createOverwriteFeed(const QSqlDatabase& db, Feed* feed, in
   q.bindValue(QSL(":custom_data"), serialized_custom_data);
 
   if (!q.exec()) {
-    auto xx = q.lastError().text();
-
     throw ApplicationException(q.lastError().text());
   }
 }
diff --git a/src/librssguard/dynamic-shortcuts/dynamicshortcutswidget.cpp b/src/librssguard/dynamic-shortcuts/dynamicshortcutswidget.cpp
index e234ecb92..eeb895161 100644
--- a/src/librssguard/dynamic-shortcuts/dynamicshortcutswidget.cpp
+++ b/src/librssguard/dynamic-shortcuts/dynamicshortcutswidget.cpp
@@ -41,7 +41,7 @@ bool DynamicShortcutsWidget::areShortcutsUnique() const {
 }
 
 void DynamicShortcutsWidget::updateShortcuts() {
-  for (const ActionBinding& binding : m_actionBindings) {
+  for (const ActionBinding& binding : qAsConst(m_actionBindings)) {
     binding.first->setShortcut(binding.second->shortcut());
   }
 }
diff --git a/src/librssguard/gui/dialogs/formaddaccount.cpp b/src/librssguard/gui/dialogs/formaddaccount.cpp
index 4143e612c..e3a55940e 100644
--- a/src/librssguard/gui/dialogs/formaddaccount.cpp
+++ b/src/librssguard/gui/dialogs/formaddaccount.cpp
@@ -58,7 +58,7 @@ ServiceEntryPoint* FormAddAccount::selectedEntryPoint() const {
 }
 
 void FormAddAccount::loadEntryPoints() {
-  for (const ServiceEntryPoint* entry_point : m_entryPoints) {
+  for (const ServiceEntryPoint* entry_point : qAsConst(m_entryPoints)) {
     QListWidgetItem* item = new QListWidgetItem(entry_point->icon(), entry_point->name(), m_ui->m_listEntryPoints);
 
     item->setToolTip(entry_point->description());
diff --git a/src/librssguard/gui/dialogs/formmain.cpp b/src/librssguard/gui/dialogs/formmain.cpp
index 6ee51a0df..bb1552b07 100755
--- a/src/librssguard/gui/dialogs/formmain.cpp
+++ b/src/librssguard/gui/dialogs/formmain.cpp
@@ -2,6 +2,7 @@
 
 #include "gui/dialogs/formmain.h"
 
+#include "database/databasefactory.h"
 #include "definitions/definitions.h"
 #include "gui/dialogs/formabout.h"
 #include "gui/dialogs/formaddaccount.h"
@@ -22,7 +23,6 @@
 #include "gui/systemtrayicon.h"
 #include "gui/tabbar.h"
 #include "miscellaneous/application.h"
-#include "database/databasefactory.h"
 #include "miscellaneous/feedreader.h"
 #include "miscellaneous/iconfactory.h"
 #include "miscellaneous/mutex.h"
@@ -257,7 +257,9 @@ void FormMain::updateAddItemMenu() {
   // NOTE: Clear here deletes items from memory but only those OWNED by the menu.
   m_ui->m_menuAddItem->clear();
 
-  for (ServiceRoot* activated_root : qApp->feedReader()->feedsModel()->serviceRoots()) {
+  auto srts = qApp->feedReader()->feedsModel()->serviceRoots();
+
+  for (ServiceRoot* activated_root : qAsConst(srts)) {
     QMenu* root_menu = new QMenu(activated_root->title(), m_ui->m_menuAddItem);
 
     root_menu->setIcon(activated_root->icon());
@@ -312,7 +314,9 @@ void FormMain::updateAddItemMenu() {
 void FormMain::updateRecycleBinMenu() {
   m_ui->m_menuRecycleBin->clear();
 
-  for (const ServiceRoot* activated_root : qApp->feedReader()->feedsModel()->serviceRoots()) {
+  auto srts = qApp->feedReader()->feedsModel()->serviceRoots();
+
+  for (const ServiceRoot* activated_root : qAsConst(srts)) {
     QMenu* root_menu = new QMenu(activated_root->title(), m_ui->m_menuRecycleBin);
 
     root_menu->setIcon(activated_root->icon());
@@ -354,7 +358,9 @@ void FormMain::updateRecycleBinMenu() {
 void FormMain::updateAccountsMenu() {
   m_ui->m_menuAccounts->clear();
 
-  for (ServiceRoot* activated_root : qApp->feedReader()->feedsModel()->serviceRoots()) {
+  auto srts = qApp->feedReader()->feedsModel()->serviceRoots();
+
+  for (ServiceRoot* activated_root : srts) {
     QMenu* root_menu = new QMenu(activated_root->title(), m_ui->m_menuAccounts);
 
     root_menu->setIcon(activated_root->icon());
diff --git a/src/librssguard/gui/dialogs/formmessagefiltersmanager.cpp b/src/librssguard/gui/dialogs/formmessagefiltersmanager.cpp
index f6a4add5e..b50c92aae 100644
--- a/src/librssguard/gui/dialogs/formmessagefiltersmanager.cpp
+++ b/src/librssguard/gui/dialogs/formmessagefiltersmanager.cpp
@@ -9,11 +9,11 @@
 #include "3rd-party/boolinq/boolinq.h"
 #include "core/messagefilter.h"
 #include "core/messagesforfiltersmodel.h"
+#include "database/databasequeries.h"
 #include "exceptions/filteringexception.h"
 #include "gui/guiutilities.h"
 #include "gui/messagebox.h"
 #include "miscellaneous/application.h"
-#include "database/databasequeries.h"
 #include "miscellaneous/feedreader.h"
 #include "miscellaneous/iconfactory.h"
 #include "network-web/webfactory.h"
@@ -157,7 +157,9 @@ void FormMessageFiltersManager::removeSelectedFilter() {
 }
 
 void FormMessageFiltersManager::loadFilters() {
-  for (auto* fltr : m_reader->messageFilters()) {
+  auto flt = m_reader->messageFilters();
+
+  for (auto* fltr : qAsConst(flt)) {
     auto* it = new QListWidgetItem(fltr->name(), m_ui.m_listFilters);
 
     it->setData(Qt::ItemDataRole::UserRole, QVariant::fromValue<MessageFilter*>(fltr));
@@ -344,7 +346,7 @@ void FormMessageFiltersManager::processCheckedFeeds() {
         }
 
         // Process changed labels.
-        for (Label* lbl : msg_backup.m_assignedLabels) {
+        for (Label* lbl : qAsConst(msg_backup.m_assignedLabels)) {
           if (!msg->m_assignedLabels.contains(lbl)) {
             // Label is not there anymore, it was deassigned.
             lbl->deassignFromMessage(*msg);
@@ -356,7 +358,7 @@ void FormMessageFiltersManager::processCheckedFeeds() {
           }
         }
 
-        for (Label* lbl : msg->m_assignedLabels) {
+        for (Label* lbl : qAsConst(msg->m_assignedLabels)) {
           if (!msg_backup.m_assignedLabels.contains(lbl)) {
             // Label is in new message, but is not in old message, it
             // was newly assigned.
@@ -428,8 +430,9 @@ void FormMessageFiltersManager::loadFilterFeedAssignments(MessageFilter* filter,
   }
 
   m_loadingFilter = true;
+  auto stf = account->getSubTreeFeeds();
 
-  for (auto* feed : account->getSubTreeFeeds()) {
+  for (auto* feed : qAsConst(stf)) {
     if (feed->messageFilters().contains(filter)) {
       m_feedsModel->sourceModel()->setItemChecked(feed, Qt::CheckState::Checked);
     }
@@ -503,10 +506,8 @@ void FormMessageFiltersManager::showFilter(MessageFilter* filter) {
 }
 
 void FormMessageFiltersManager::loadAccounts() {
-  for (auto* acc : m_accounts) {
-    m_ui.m_cmbAccounts->addItem(acc->icon(),
-                                acc->title(),
-                                QVariant::fromValue(acc));
+  for (auto* acc : qAsConst(m_accounts)) {
+    m_ui.m_cmbAccounts->addItem(acc->icon(), acc->title(), QVariant::fromValue(acc));
   }
 }
 
diff --git a/src/librssguard/gui/dialogs/formsettings.cpp b/src/librssguard/gui/dialogs/formsettings.cpp
index 67cd04ad3..dcd7e4d22 100644
--- a/src/librssguard/gui/dialogs/formsettings.cpp
+++ b/src/librssguard/gui/dialogs/formsettings.cpp
@@ -56,7 +56,7 @@ void FormSettings::applySettings() {
   m_settings.checkSettings();
   QStringList panels_for_restart;
 
-  for (SettingsPanel* panel : m_panels) {
+  for (SettingsPanel* panel : qAsConst(m_panels)) {
     if (panel->isDirty()) {
       panel->saveSettings();
     }
@@ -94,7 +94,7 @@ void FormSettings::applySettings() {
 void FormSettings::cancelSettings() {
   QStringList changed_panels;
 
-  for (SettingsPanel* panel : m_panels) {
+  for (SettingsPanel* panel : qAsConst(m_panels)) {
     if (panel->isDirty()) {
       changed_panels.append(panel->title().toLower());
     }
diff --git a/src/librssguard/gui/dialogs/formupdate.cpp b/src/librssguard/gui/dialogs/formupdate.cpp
index b9f20d2d1..fea894a93 100644
--- a/src/librssguard/gui/dialogs/formupdate.cpp
+++ b/src/librssguard/gui/dialogs/formupdate.cpp
@@ -148,7 +148,7 @@ void FormUpdate::saveUpdateFile(const QByteArray& file_contents) {
 void FormUpdate::loadAvailableFiles() {
   m_ui.m_listFiles->clear();
 
-  for (const UpdateUrl& url : m_updateInfo.m_urls) {
+  for (const UpdateUrl& url : qAsConst(m_updateInfo.m_urls)) {
     if (SystemFactory::supportedUpdateFiles().match(url.m_name).hasMatch()) {
       QListWidgetItem* item = new QListWidgetItem(url.m_name + tr(" (size ") + url.m_size + QSL(")"));
 
diff --git a/src/librssguard/gui/discoverfeedsbutton.cpp b/src/librssguard/gui/discoverfeedsbutton.cpp
index 74764ccd7..a7dc064f2 100644
--- a/src/librssguard/gui/discoverfeedsbutton.cpp
+++ b/src/librssguard/gui/discoverfeedsbutton.cpp
@@ -60,12 +60,13 @@ void DiscoverFeedsButton::linkTriggered(QAction* action) {
 
 void DiscoverFeedsButton::fillMenu() {
   menu()->clear();
+  auto srts = qApp->feedReader()->feedsModel()->serviceRoots();
 
-  for (const ServiceRoot* root : qApp->feedReader()->feedsModel()->serviceRoots()) {
+  for (const ServiceRoot* root : qAsConst(srts)) {
     if (root->supportsFeedAdding()) {
       QMenu* root_menu = menu()->addMenu(root->icon(), root->title());
 
-      for (const QString& url : m_addresses) {
+      for (const QString& url : qAsConst(m_addresses)) {
         QAction* url_action = root_menu->addAction(root->icon(), url);
 
         url_action->setProperty("url", url);
diff --git a/src/librssguard/gui/feedsview.cpp b/src/librssguard/gui/feedsview.cpp
index 510b4feb5..3af9fd0ec 100755
--- a/src/librssguard/gui/feedsview.cpp
+++ b/src/librssguard/gui/feedsview.cpp
@@ -717,7 +717,7 @@ void FeedsView::selectionChanged(const QItemSelection& selected, const QItemSele
 
   if (!selectedIndexes().isEmpty() &&
       qApp->settings()->value(GROUP(Feeds), SETTING(Feeds::AutoExpandOnSelection)).toBool()) {
-    expand(selectedIndexes().first());
+    expand(selectedIndexes().constFirst());
   }
 }
 
diff --git a/src/librssguard/gui/labelsmenu.cpp b/src/librssguard/gui/labelsmenu.cpp
index 8c955798a..7fda03e49 100644
--- a/src/librssguard/gui/labelsmenu.cpp
+++ b/src/librssguard/gui/labelsmenu.cpp
@@ -3,8 +3,8 @@
 #include "gui/labelsmenu.h"
 
 #include "3rd-party/boolinq/boolinq.h"
-#include "miscellaneous/application.h"
 #include "database/databasequeries.h"
+#include "miscellaneous/application.h"
 #include "miscellaneous/iconfactory.h"
 
 #include <QCheckBox>
@@ -22,7 +22,7 @@ LabelsMenu::LabelsMenu(const QList<Message>& messages, const QList<Label*>& labe
     addAction(act_not_labels);
   }
   else {
-    QSqlDatabase db = qApp->database()->driver()->connection(metaObject()->className());
+    QSqlDatabase db = qApp->database()->driver()->connection(QSL("LabelsMenu"));
 
     for (Label* label: boolinq::from(labels).orderBy([](const Label* label) {
       return label->title().toLower();
@@ -73,13 +73,13 @@ void LabelsMenu::changeLabelAssignment(Qt::CheckState state) {
   if (origin != nullptr) {
     if (state == Qt::CheckState::Checked) {
       // Assign this label to selected messages.
-      for (const auto& msg : m_messages) {
+      for (const auto& msg : qAsConst(m_messages)) {
         origin->label()->assignToMessage(msg);
       }
     }
     else if (state == Qt::CheckState::Unchecked) {
       // Remove label from selected messages.
-      for (const auto& msg : m_messages) {
+      for (const auto& msg : qAsConst(m_messages)) {
         origin->label()->deassignFromMessage(msg);
       }
     }
@@ -140,7 +140,7 @@ void LabelAction::updateActionForState() {
       break;
 
     case Qt::CheckState::PartiallyChecked:
-      highlight = QColor("#ff8c00");
+      highlight = QColor(100, 50, 0);
       break;
 
     case Qt::CheckState::Unchecked:
diff --git a/src/librssguard/gui/messagepreviewer.cpp b/src/librssguard/gui/messagepreviewer.cpp
index 7d085dcb0..950ee67d1 100755
--- a/src/librssguard/gui/messagepreviewer.cpp
+++ b/src/librssguard/gui/messagepreviewer.cpp
@@ -231,8 +231,9 @@ void MessagePreviewer::updateLabels(bool only_clear) {
   if (m_root.data() != nullptr && !m_root.data()->getParentServiceRoot()->labelsNode()->labels().isEmpty()) {
     m_separator = m_toolBar->addSeparator();
     QSqlDatabase database = qApp->database()->driver()->connection(metaObject()->className());
+    auto lbls = m_root.data()->getParentServiceRoot()->labelsNode()->labels();
 
-    for (auto* label : m_root.data()->getParentServiceRoot()->labelsNode()->labels()) {
+    for (auto* label : lbls) {
       LabelButton* btn_label = new LabelButton(this);
 
       btn_label->setLabel(label);
diff --git a/src/librssguard/gui/messagesview.cpp b/src/librssguard/gui/messagesview.cpp
index 01851c67a..6a14f71c0 100644
--- a/src/librssguard/gui/messagesview.cpp
+++ b/src/librssguard/gui/messagesview.cpp
@@ -209,10 +209,11 @@ void MessagesView::initializeContextMenu() {
   // External tools.
   QFileIconProvider icon_provider;
   QMenu* menu_ext_tools = new QMenu(tr("Open with external tool"), m_contextMenu);
+  auto tools = ExternalTool::toolsFromSettings();
 
   menu_ext_tools->setIcon(qApp->icons()->fromTheme(QSL("document-open")));
 
-  for (const ExternalTool& tool : ExternalTool::toolsFromSettings()) {
+  for (const ExternalTool& tool : qAsConst(tools)) {
     QAction* act_tool = new QAction(QFileInfo(tool.executable()).fileName(), menu_ext_tools);
 
     act_tool->setIcon(icon_provider.icon(tool.executable()));
@@ -375,7 +376,9 @@ void MessagesView::switchShowUnreadOnly(bool set_new_value, bool show_unread_onl
 }
 
 void MessagesView::openSelectedSourceMessagesExternally() {
-  for (const QModelIndex& index : selectionModel()->selectedRows()) {
+  auto rws = selectionModel()->selectedRows();
+
+  for (const QModelIndex& index : qAsConst(rws)) {
     QString link = m_sourceModel->messageAt(m_proxyModel->mapToSource(index).row())
                    .m_url
                    .replace(QRegularExpression("[\\t\\n]"), QString());
@@ -397,8 +400,9 @@ void MessagesView::openSelectedSourceMessagesExternally() {
 
 void MessagesView::openSelectedMessagesInternally() {
   QList<Message> messages;
+  auto rws = selectionModel()->selectedRows();
 
-  for (const QModelIndex& index : selectionModel()->selectedRows()) {
+  for (const QModelIndex& index : qAsConst(rws)) {
     messages << m_sourceModel->messageAt(m_proxyModel->mapToSource(index).row());
   }
 
@@ -591,8 +595,9 @@ void MessagesView::openSelectedMessagesWithExternalTool() {
 
   if (sndr != nullptr) {
     auto tool = sndr->data().value<ExternalTool>();
+    auto rws = selectionModel()->selectedRows();
 
-    for (const QModelIndex& index : selectionModel()->selectedRows()) {
+    for (const QModelIndex& index : qAsConst(rws)) {
       const QString link = m_sourceModel->messageAt(m_proxyModel->mapToSource(index).row())
                            .m_url
                            .replace(QRegularExpression("[\\t\\n]"), QString());
diff --git a/src/librssguard/gui/settings/settingsfeedsmessages.cpp b/src/librssguard/gui/settings/settingsfeedsmessages.cpp
index 09c66d53c..550d4aef4 100644
--- a/src/librssguard/gui/settings/settingsfeedsmessages.cpp
+++ b/src/librssguard/gui/settings/settingsfeedsmessages.cpp
@@ -92,8 +92,9 @@ void SettingsFeedsMessages::initializeMessageDateFormats() {
   QStringList best_formats;
   const QDateTime current_dt = QDateTime::currentDateTime();
   const QLocale current_locale = qApp->localization()->loadedLocale();
+  auto installed_languages = qApp->localization()->installedLanguages();
 
-  for (const Language& lang : qApp->localization()->installedLanguages()) {
+  for (const Language& lang : qAsConst(installed_languages)) {
     QLocale locale(lang.m_code);
 
     best_formats << locale.dateTimeFormat(QLocale::LongFormat)
@@ -103,7 +104,7 @@ void SettingsFeedsMessages::initializeMessageDateFormats() {
 
   best_formats.removeDuplicates();
 
-  for (const QString& format : best_formats) {
+  for (const QString& format : qAsConst(best_formats)) {
     m_ui->m_cmbMessagesDateTimeFormat->addItem(current_locale.toString(current_dt, format), format);
   }
 }