Ensure that X-OC-MTime header is an integer also with chunked uploads

This commit extends the changes introduced in pull request #3793 also to
chunked uploads.

The "sanitizeMTime" method name is the same used in the equivalent pull
request to this one from ownCloud (28066).

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

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

@@ -210,11 +210,7 @@ class File extends Node implements IFile {
 			// allow sync clients to send the mtime along in a header
 			$request = \OC::$server->getRequest();
 			if (isset($request->server['HTTP_X_OC_MTIME'])) {
-				$mtimeStr = $request->server['HTTP_X_OC_MTIME'];
-				if (!is_numeric($mtimeStr)) {
-					throw new \InvalidArgumentException('X-OC-Mtime header must be an integer (unix timestamp).');
-				}
-				$mtime = intval($mtimeStr);
+				$mtime = $this->sanitizeMtime($request->server['HTTP_X_OC_MTIME']);
 				if ($this->fileView->touch($this->path, $mtime)) {
 					header('X-OC-MTime: accepted');
 				}
@@ -472,7 +468,8 @@ class File extends Node implements IFile {
 				// allow sync clients to send the mtime along in a header
 				$request = \OC::$server->getRequest();
 				if (isset($request->server['HTTP_X_OC_MTIME'])) {
-					if ($targetStorage->touch($targetInternalPath, $request->server['HTTP_X_OC_MTIME'])) {
+					$mtime = $this->sanitizeMtime($request->server['HTTP_X_OC_MTIME']);
+					if ($targetStorage->touch($targetInternalPath, $mtime)) {
 						header('X-OC-MTime: accepted');
 					}
 				}
@@ -570,6 +567,14 @@ class File extends Node implements IFile {
 		throw new \Sabre\DAV\Exception($e->getMessage(), 0, $e);
 	}
 
+	private function sanitizeMtime($mtimeFromRequest) {
+		if (!is_numeric($mtimeFromRequest)) {
+			throw new \InvalidArgumentException('X-OC-MTime header must be an integer (unix timestamp).');
+		}
+
+		return intval($mtimeFromRequest);
+	}
+
 	/**
 	 * Get the checksum for this file
 	 *