Lock a file during the completion of its upload

changelog/unreleased/enterprise-5052

@@ -0,0 +1,6 @@
+Bugfix: Don't publish upload if we can't finish the transaction in the client
+
+When a file ges locked during an upload we aborted after the upload finished on the server.
+Resulting in a divergence of the local and remote state which could lead to conflicts.
+
+https://github.com/owncloud/enterprise/issues/5052

src/libsync/propagateupload.cpp

@@ -570,6 +570,10 @@ void PropagateUploadFileCommon::finalize()
     if (quotaIt != propagator()->_folderQuota.end())
         quotaIt.value() -= _item->_size;
 
+
+#ifdef Q_OS_WIN
+    m_fileLock.close();
+#endif
     // Update the database entry
     const auto result = propagator()->updateMetadata(*_item);
     if (!result) {

src/libsync/propagateupload.h

@@ -244,6 +244,10 @@ public slots:
 
     /** Bases headers that need to be sent on the PUT, or in the MOVE for chunking-ng */
     QMap<QByteArray, QByteArray> headers();
+
+#ifdef Q_OS_WIN
+    Utility::Handle m_fileLock;
+#endif
 };
 
 /**

src/libsync/propagateuploadng.cpp

@@ -358,6 +358,19 @@ void PropagateUploadFileNG::doFinalMove()
 
     const QUrl source = Utility::concatUrlPath(chunkUrl(), QStringLiteral("/.file"));
 
+#ifdef Q_OS_WIN
+    // Try to accuire a lock on the file and keep it until we done.
+    // If the file is locked, abort before we perform the move on the server
+    const QString fileName = propagator()->fullLocalPath(_item->_file);
+    const auto lockMode = propagator()->syncOptions().requiredLockMode();
+    m_fileLock = FileSystem::lockFile(fileName, lockMode);
+    if (!m_fileLock) {
+        emit propagator()->seenLockedFile(fileName, lockMode);
+        abortWithError(SyncFileItem::SoftError, tr("%1 the file is currently in use").arg(QDir::toNativeSeparators(fileName)));
+        return;
+    }
+#endif
+
     auto job = new MoveJob(propagator()->account(), source, destination, headers, this);
     _jobs.append(job);
     connect(job, &MoveJob::finishedSignal, this, &PropagateUploadFileNG::slotMoveJobFinished);