Check permissions when labeling a version

Signed-off-by: Louis Chemineau <louis@chmn.me>

Author: artonge

apps/files_versions/lib/Versions/LegacyVersionsBackend.php

@@ -211,6 +211,10 @@ public function getVersionFile(IUser $user, FileInfo $sourceFile, $revision): Fi
 	}
 
 	public function setVersionLabel(IVersion $version, string $label): void {
+		if (!$this->currentUserHasPermissions($version, \OCP\Constants::PERMISSION_UPDATE)) {
+			throw new Forbidden('You cannot label this version because you do not have update permissions on the source file.');
+		}
+
 		$versionEntity = $this->versionsMapper->findVersionForFileId(
 			$version->getSourceFile()->getId(),
 			$version->getTimestamp(),