Merge pull request #14273 from nextcloud/backport/14210/stable15

[stable15] Fix empty file uploads to S3 (and other streaming storages)

3rdparty

@@ -1 +1 @@
-Subproject commit 4c31d7509c9ab8388429a5c3e671dc3e49f9fe92
+Subproject commit 88f57274c0fa29e05a08351944915b0772a2fc2a

apps/dav/lib/Connector/Sabre/File.php

@@ -36,6 +36,7 @@
 
 namespace OCA\DAV\Connector\Sabre;
 
+use Icewind\Streams\CallbackWrapper;
 use OC\AppFramework\Http\Request;
 use OC\Files\Filesystem;
 use OC\Files\View;
@@ -166,10 +167,26 @@ class File extends Node implements IFile {
 			}
 
 			if ($partStorage->instanceOfStorage(Storage\IWriteStreamStorage::class)) {
-				$count = $partStorage->writeStream($internalPartPath, $data);
+
+				if (!is_resource($data)) {
+					$data = fopen('php://temp', 'r+');
+					fwrite($data, 'foobar');
+					rewind($data);
+				}
+
+				$isEOF = false;
+				$wrappedData = CallbackWrapper::wrap($data, null, null, null, null, function($stream) use (&$isEOF) {
+					$isEOF = feof($stream);
+				});
+
+				$count = $partStorage->writeStream($internalPartPath, $wrappedData);
 				$result = $count > 0;
+
 				if ($result === false) {
-					$result = feof($data);
+					$result = $isEOF;
+					if (is_resource($wrappedData)) {
+						$result = feof($wrappedData);
+					}
 				}
 
 			} else {

lib/private/Files/ObjectStore/S3ObjectTrait.php

@@ -23,8 +23,11 @@
 
 namespace OC\Files\ObjectStore;
 
+use Aws\S3\Exception\S3MultipartUploadException;
 use Aws\S3\MultipartUploader;
+use Aws\S3\ObjectUploader;
 use Aws\S3\S3Client;
+use Icewind\Streams\CallbackWrapper;
 
 const S3_UPLOAD_PART_SIZE = 524288000; // 500MB
 
@@ -73,12 +76,30 @@ trait S3ObjectTrait {
 	 * @since 7.0.0
 	 */
 	function writeObject($urn, $stream) {
-		$uploader = new MultipartUploader($this->getConnection(), $stream, [
+		$count = 0;
+		$countStream = CallbackWrapper::wrap($stream, function ($read) use (&$count) {
+			$count += $read;
+		});
+
+		$uploader = new MultipartUploader($this->getConnection(), $countStream, [
 			'bucket' => $this->bucket,
 			'key' => $urn,
 			'part_size' => S3_UPLOAD_PART_SIZE
 		]);
-		$uploader->upload();
+
+		try {
+			$uploader->upload();
+		} catch (S3MultipartUploadException $e) {
+			// This is an emty file so just touch it then
+			if ($count === 0 && feof($countStream)) {
+				$uploader = new ObjectUploader($this->getConnection(), $this->bucket, $urn, '');
+				$uploader->upload();
+			} else {
+				throw $e;
+			}
+		}
+
+		fclose($countStream);
 	}
 
 	/**