fix: undefined share for preview

Signed-off-by: Elizabeth Danzberger <lizzy7128@tutanota.de>

Author: elzody

lib/Listener/BeforeFetchPreviewListener.php

@@ -39,14 +39,17 @@ public function handle(Event $event): void {
 		$shareToken = $this->request->getParam('token');
 
 		try {
-			$share = $shareToken ?
-				// Get different share for public previews as the share from the node is only set for mounted shares
-				$this->shareManager->getShareByToken($shareToken)
-				// Get share for internal shares
-				: $this->helper->getShareFromNode($event->getNode());
+			// Get different share for public previews as the share from the node is only set for mounted shares
+			$shareByToken = $shareToken ? $this->shareManager->getShareByToken($shareToken) : null;
+
+			// Get share for internal shares
+			$shareFromNode = $this->helper->getShareFromNode($event->getNode());
 		} catch (ShareNotFound) {
 		}
 
+		// Do not leave as undefined if neither found
+		$share = $shareByToken ?? $shareFromNode ?? null;
+
 		$userId = $this->userSession->getUser() ? $this->userSession->getUser()->getUID() : null;
 		if ($this->permissionManager->shouldWatermark($event->getNode(), $userId, $share)) {
 			throw new NotFoundException();