Add a wrapper to determine if a file is EOF

The stream is already closed at this point. Which means feof will always
return false. We have to determine if the stream is EOF in the
preCloseCallback. And pass this info along. Then the logic works as
expected.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

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 +167,15 @@ class File extends Node implements IFile {
 			}
 
 			if ($partStorage->instanceOfStorage(Storage\IWriteStreamStorage::class)) {
-				$count = $partStorage->writeStream($internalPartPath, $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;
 				}
 
 			} else {