Sync: Fix sync of deletions during 503. #2894

src/libsync/syncengine.cpp

@@ -384,6 +384,7 @@ int SyncEngine::treewalkFile( TREE_WALK_FILE *file, bool remote )
     case CSYNC_STATUS_STORAGE_UNAVAILABLE:
         item._errorString = QLatin1String("Directory temporarily not available on server.");
         item._status = SyncFileItem::SoftError;
+        _temporarilyUnavailablePaths.insert(item._file);
         break;
     default:
         Q_ASSERT("Non handled error-status");
@@ -700,6 +701,7 @@ void SyncEngine::slotDiscoveryJobFinished(int discoveryResult)
     _hasRemoveFile = false;
     bool walkOk = true;
     _seenFiles.clear();
+    _temporarilyUnavailablePaths.clear();
 
     if( csync_walk_local_tree(_csync_ctx, &treewalkLocal, 0) < 0 ) {
         qDebug() << "Error in local treewalk.";
@@ -863,7 +865,7 @@ void SyncEngine::slotFinished()
     _anotherSyncNeeded = _anotherSyncNeeded || _propagator->_anotherSyncNeeded;
 
     // emit the treewalk results.
-    if( ! _journal->postSyncCleanup( _seenFiles ) ) {
+    if( ! _journal->postSyncCleanup( _seenFiles, _temporarilyUnavailablePaths ) ) {
         qDebug() << "Cleaning of synced ";
     }
 

src/libsync/syncengine.h

@@ -159,7 +159,21 @@ private:
     QPointer<DiscoveryMainThread> _discoveryMainThread;
     QSharedPointer <OwncloudPropagator> _propagator;
     QString _lastDeleted; // if the last item was a path and it has been deleted
+
+    // After a sync, only the syncdb entries whose filenames appear in this
+    // set will be kept. See _temporarilyUnavailablePaths.
     QSet<QString> _seenFiles;
+
+    // Some paths might be temporarily unavailable on the server, for
+    // example due to 503 Storage not available. Deleting information
+    // about the files from the database in these cases would lead to
+    // incorrect synchronization.
+    // Therefore all syncdb entries whose filename starts with one of
+    // the paths in this set will be kept.
+    // The specific case that fails otherwise is deleting a local file
+    // while the remote says storage not available.
+    QSet<QString> _temporarilyUnavailablePaths;
+
     QThread _thread;
 
     Progress::Info _progressInfo;

src/libsync/syncjournaldb.cpp

@@ -698,7 +698,8 @@ SyncJournalFileRecord SyncJournalDb::getFileRecord( const QString& filename )
     return rec;
 }
 
-bool SyncJournalDb::postSyncCleanup(const QSet<QString> &items )
+bool SyncJournalDb::postSyncCleanup(const QSet<QString>& filepathsToKeep,
+                                    const QSet<QString>& prefixesToKeep)
 {
     QMutexLocker locker(&_mutex);
 
@@ -719,8 +720,16 @@ bool SyncJournalDb::postSyncCleanup(const QSet<QString> &items )
 
     while(query.next()) {
         const QString file = query.stringValue(1);
-        bool contained = items.contains(file);
-        if( !contained ) {
+        bool keep = filepathsToKeep.contains(file);
+        if( !keep ) {
+            foreach( const QString & prefix, prefixesToKeep ) {
+                if( file.startsWith(prefix) ) {
+                    keep = true;
+                    break;
+                }
+            }
+        }
+        if( !keep ) {
             superfluousItems.append(query.stringValue(0));
         }
     }

src/libsync/syncjournaldb.h

@@ -97,7 +97,8 @@ public:
      */
     void avoidReadFromDbOnNextSync(const QString& fileName);
 
-    bool postSyncCleanup( const QSet<QString>& items );
+    bool postSyncCleanup(const QSet<QString>& filepathsToKeep,
+                         const QSet<QString>& prefixesToKeep);
 
     /* Because sqlite transactions is really slow, we encapsulate everything in big transactions
      * Commit will actually commit the transaction and create a new one.