[buteo-sync-plugins-social] Prevent purge of deleted Google account c…

…ontacts unless sync succeeds. Contributes to JB#38210

src/google/google-contacts/googletwowaycontactsyncadaptor.cpp

@@ -69,6 +69,7 @@ GoogleTwoWayContactSyncAdaptor::GoogleTwoWayContactSyncAdaptor(QObject *parent)
     : GoogleDataTypeSyncAdaptor(SocialNetworkSyncAdaptor::Contacts, parent)
     , QtContactsSqliteExtensions::TwoWayContactSyncAdapter(QStringLiteral("google"))
     , m_workerObject(new GoogleContactImageDownloader())
+    , m_allowFinalCleanup(false)
 {
     connect(m_workerObject, &AbstractImageDownloader::imageDownloaded,
             this, &GoogleTwoWayContactSyncAdaptor::imageDownloaded);
@@ -824,6 +825,9 @@ void GoogleTwoWayContactSyncAdaptor::finalize(int accountId)
         return;
     }
 
+    // sync was successful, allow cleaning up contacts from removed accounts.
+    m_allowFinalCleanup = true;
+
     // first, ensure we update any avatars required.
     if (m_downloadedContactAvatars[accountId].size()) {
         // find the contacts we need to update from our mutated prev remote list.
@@ -884,6 +888,15 @@ void GoogleTwoWayContactSyncAdaptor::finalize(int accountId)
 
 void GoogleTwoWayContactSyncAdaptor::finalCleanup()
 {
+    // Only perform the cleanup if the sync cycle was successful.
+    // Note: purgeDataForOldAccount() will still be invoked by Buteo
+    // in response to the account being deleted when restoring the
+    // backup, so we cannot avoid the problem of "lost contacts"
+    // completely.  See JB#38210 for more information.
+    if (!m_allowFinalCleanup) {
+        return;
+    }
+
     // Synchronously find any contacts which need to be removed,
     // which were somehow "left behind" by the sync process.
     // Also, determine if any avatars were not synced, and remove those details.

src/google/google-contacts/googletwowaycontactsyncadaptor.h

@@ -117,6 +117,8 @@ private Q_SLOTS:
     QMap<int, int> m_apiRequestsRemaining;
     QMap<int, QMap<QString, QString> > m_queuedAvatarsForDownload; // contact guid -> remote avatar path
     QMap<int, QMap<QString, QString> > m_downloadedContactAvatars; // contact guid -> local file path
+
+    bool m_allowFinalCleanup;
 };
 
 #endif // GOOGLETWOWAYCONTACTSYNCADAPTOR_H