fix #465

src/librssguard/database/databasequeries.cpp

@@ -1524,7 +1524,10 @@ bool DatabaseQueries::deleteAccount(const QSqlDatabase& db, int account_id) {
   return true;
 }
 
-bool DatabaseQueries::deleteAccountData(const QSqlDatabase& db, int account_id, bool delete_messages_too) {
+bool DatabaseQueries::deleteAccountData(const QSqlDatabase& db,
+                                        int account_id,
+                                        bool delete_messages_too,
+                                        bool delete_labels_too) {
   bool result = true;
   QSqlQuery q(db);
 
@@ -1545,15 +1548,16 @@ bool DatabaseQueries::deleteAccountData(const QSqlDatabase& db, int account_id,
   result &= q.exec();
 
   if (delete_messages_too) {
-    // If we delete message, make sure to delete message/label assignments too.
     q.prepare(QSL("DELETE FROM LabelsInMessages WHERE account_id = :account_id;"));
     q.bindValue(QSL(":account_id"), account_id);
     result &= q.exec();
   }
 
-  q.prepare(QSL("DELETE FROM Labels WHERE account_id = :account_id;"));
+  if (delete_labels_too) {
-  q.bindValue(QSL(":account_id"), account_id);
+    q.prepare(QSL("DELETE FROM Labels WHERE account_id = :account_id;"));
-  result &= q.exec();
+    q.bindValue(QSL(":account_id"), account_id);
+    result &= q.exec();
+  }
 
   return result;
 }

src/librssguard/database/databasequeries.h

@@ -116,7 +116,7 @@ class DatabaseQueries {
     static QPair<int, int> updateMessages(QSqlDatabase db, const QList<Message>& messages,
                                           Feed* feed, bool force_update, bool* ok = nullptr);
     static bool deleteAccount(const QSqlDatabase& db, int account_id);
-    static bool deleteAccountData(const QSqlDatabase& db, int account_id, bool delete_messages_too);
+    static bool deleteAccountData(const QSqlDatabase& db, int account_id, bool delete_messages_too, bool delete_labels_too);
     static bool cleanLabelledMessages(const QSqlDatabase& db, bool clean_read_only, Label* label);
     static bool cleanImportantMessages(const QSqlDatabase& db, bool clean_read_only, int account_id);
     static bool cleanUnreadMessages(const QSqlDatabase& db, int account_id);

src/librssguard/services/abstract/serviceroot.cpp

@@ -167,10 +167,10 @@ bool ServiceRoot::canBeDeleted() const {
 
 void ServiceRoot::completelyRemoveAllData() {
   // Purge old data from SQL and clean all model items.
-  cleanAllItemsFromModel();
+  cleanAllItemsFromModel(true);
-  removeOldAccountFromDatabase(true);
+  removeOldAccountFromDatabase(true, true);
   updateCounts(true);
-  itemChanged(QList<RootItem*>() << this);
+  itemChanged({ this });
   requestReloadMessageList(true);
 }
 
@@ -188,13 +188,16 @@ QIcon ServiceRoot::feedIconForMessage(const QString& feed_custom_id) const {
   }
 }
 
-void ServiceRoot::removeOldAccountFromDatabase(bool including_messages) {
+void ServiceRoot::removeOldAccountFromDatabase(bool delete_messages_too, bool delete_labels_too) {
   QSqlDatabase database = qApp->database()->driver()->connection(metaObject()->className());
 
-  DatabaseQueries::deleteAccountData(database, accountId(), including_messages);
+  DatabaseQueries::deleteAccountData(database,
+                                     accountId(),
+                                     delete_messages_too,
+                                     delete_labels_too);
 }
 
-void ServiceRoot::cleanAllItemsFromModel() {
+void ServiceRoot::cleanAllItemsFromModel(bool clean_labels_too) {
   auto chi = childItems();
 
   for (RootItem* top_level_item : qAsConst(chi)) {
@@ -206,7 +209,7 @@ void ServiceRoot::cleanAllItemsFromModel() {
     }
   }
 
-  if (labelsNode() != nullptr) {
+  if (labelsNode() != nullptr && clean_labels_too) {
     auto lbl_chi = labelsNode()->childItems();
 
     for (RootItem* lbl : qAsConst(lbl_chi)) {
@@ -425,8 +428,13 @@ void ServiceRoot::syncIn() {
     auto feed_custom_data = storeCustomFeedsData();
 
     // Remove from feeds model, then from SQL but leave messages intact.
-    cleanAllItemsFromModel();
+    bool uses_remote_labels = (supportedLabelOperations() & LabelOperation::Synchronised) == LabelOperation::Synchronised;
-    removeOldAccountFromDatabase(false);
+
+    // Remove stuff.
+    cleanAllItemsFromModel(uses_remote_labels);
+    removeOldAccountFromDatabase(false, uses_remote_labels);
+
+    // Restore some local settings to feeds etc.
     restoreCustomFeedsData(feed_custom_data, new_tree->getHashedSubTreeFeeds());
 
     // Model is clean, now store new tree into DB and

src/librssguard/services/abstract/serviceroot.h

@@ -33,7 +33,11 @@ class ServiceRoot : public RootItem {
     enum class LabelOperation {
       Adding = 1,
       Editing = 2,
-      Deleting = 4
+      Deleting = 4,
+
+      // NOTE: Service fetches list of labels from remote source
+      // and does not use local offline labels.
+      Synchronised = 8
     };
 
     enum class BagOfMessages {
@@ -226,9 +230,9 @@ class ServiceRoot : public RootItem {
 
     // Removes all messages/categories/feeds which are
     // associated with this account.
-    void removeOldAccountFromDatabase(bool including_messages);
+    void removeOldAccountFromDatabase(bool delete_messages_too, bool delete_labels_too);
     void storeNewFeedTree(RootItem* root);
-    void cleanAllItemsFromModel();
+    void cleanAllItemsFromModel(bool clean_labels_too);
     void appendCommonNodes();
 
     // Removes messages which do not belong to any

src/librssguard/services/feedly/feedlyserviceroot.cpp

@@ -233,7 +233,7 @@ void FeedlyServiceRoot::saveAllCachedData(bool ignore_errors) {
 }
 
 ServiceRoot::LabelOperation FeedlyServiceRoot::supportedLabelOperations() const {
-  return LabelOperation(0);
+  return ServiceRoot::LabelOperation::Synchronised;
 }
 
 void FeedlyServiceRoot::updateTitle() {

src/librssguard/services/greader/greaderserviceroot.cpp

@@ -257,7 +257,7 @@ void GreaderServiceRoot::saveAllCachedData(bool ignore_errors) {
 }
 
 ServiceRoot::LabelOperation GreaderServiceRoot::supportedLabelOperations() const {
-  return LabelOperation(0);
+  return ServiceRoot::LabelOperation::Synchronised;
 }
 
 void GreaderServiceRoot::updateTitleIcon() {

src/librssguard/services/tt-rss/ttrssserviceroot.cpp

@@ -34,7 +34,7 @@ TtRssServiceRoot::~TtRssServiceRoot() {
 }
 
 ServiceRoot::LabelOperation TtRssServiceRoot::supportedLabelOperations() const {
-  return ServiceRoot::LabelOperation(0);
+  return ServiceRoot::LabelOperation::Synchronised;
 }
 
 void TtRssServiceRoot::start(bool freshly_activated) {