Merge pull request #54314 from nextcloud/backport/54309/stable30

[stable30] fix: use correct return value for `has-preview` dav property

Author: solracsf

apps/files_trashbin/lib/Sabre/TrashbinPlugin.php

@@ -111,8 +111,8 @@ public function propFind(PropFind $propFind, INode $node) {
 			return $node->getFileId();
 		});
 
-		$propFind->handle(FilesPlugin::HAS_PREVIEW_PROPERTYNAME, function () use ($node) {
-			return $this->previewManager->isAvailable($node->getFileInfo());
+		$propFind->handle(FilesPlugin::HAS_PREVIEW_PROPERTYNAME, function () use ($node): string {
+			return $this->previewManager->isAvailable($node->getFileInfo()) ? 'true' : 'false';
 		});
 
 		$propFind->handle(FilesPlugin::MOUNT_TYPE_PROPERTYNAME, function () {

apps/files_versions/lib/Sabre/Plugin.php

@@ -78,7 +78,10 @@ public function propFind(PropFind $propFind, INode $node): void {
 		if ($node instanceof VersionFile) {
 			$propFind->handle(self::VERSION_LABEL, fn () => $node->getMetadataValue('label'));
 			$propFind->handle(self::VERSION_AUTHOR, fn () => $node->getMetadataValue('author'));
-			$propFind->handle(FilesPlugin::HAS_PREVIEW_PROPERTYNAME, fn () => $this->previewManager->isMimeSupported($node->getContentType()));
+			$propFind->handle(
+				FilesPlugin::HAS_PREVIEW_PROPERTYNAME,
+				fn (): string => $this->previewManager->isMimeSupported($node->getContentType()) ? 'true' : 'false',
+			);
 		}
 	}