only create the file cache entry after the empty file was created...

only create the file cache entry after the empty file was created successfully, otherwise file_exists() call on the initial file_put_content() will indicate that the file already exists

Signed-off-by: Bjoern Schiessle <bjoern@schiessle.org>

lib/private/Files/ObjectStore/ObjectStoreStorage.php

@@ -351,25 +351,24 @@ class ObjectStoreStorage extends \OC\Files\Storage\Common {
 			$stat['mtime'] = $mtime;
 			$this->getCache()->update($stat['fileid'], $stat);
 		} else {
-			$mimeType = \OC::$server->getMimeTypeDetector()->detectPath($path);
-			// create new file
-			$stat = array(
-				'etag' => $this->getETag($path),
-				'mimetype' => $mimeType,
-				'size' => 0,
-				'mtime' => $mtime,
-				'storage_mtime' => $mtime,
-				'permissions' => \OCP\Constants::PERMISSION_ALL - \OCP\Constants::PERMISSION_CREATE,
-			);
-			$fileId = $this->getCache()->put($path, $stat);
 			try {
-				//read an empty file from memory
+				//create a empty file, need to have at least on char to make it
+				// work with all object storage implementations
 				$this->file_put_contents($path, ' ');
+				$mimeType = \OC::$server->getMimeTypeDetector()->detectPath($path);
+				$stat = array(
+					'etag' => $this->getETag($path),
+					'mimetype' => $mimeType,
+					'size' => 0,
+					'mtime' => $mtime,
+					'storage_mtime' => $mtime,
+					'permissions' => \OCP\Constants::PERMISSION_ALL - \OCP\Constants::PERMISSION_CREATE,
+				);
+				$this->getCache()->put($path, $stat);
 			} catch (\Exception $ex) {
-				$this->getCache()->remove($path);
 				$this->logger->logException($ex, [
 					'app' => 'objectstore',
-					'message' => 'Could not create object ' . $this->getURN($fileId) . ' for ' . $path,
+					'message' => 'Could not create object for ' . $path,
 				]);
 				return false;
 			}