Remove the notification if accepting/declining failed because of 404

apps/files_sharing/api/remote.php

@@ -67,6 +67,9 @@ class Remote {
 			return new \OC_OCS_Result();
 		}
 
+		// Make sure the user has no notification for something that does not exist anymore.
+		$externalManager->processNotification((int) $params['id']);
+
 		return new \OC_OCS_Result(null, 404, "wrong share ID, share doesn't exist.");
 	}
 
@@ -90,12 +93,15 @@ class Remote {
 			return new \OC_OCS_Result();
 		}
 
+		// Make sure the user has no notification for something that does not exist anymore.
+		$externalManager->processNotification((int) $params['id']);
+
 		return new \OC_OCS_Result(null, 404, "wrong share ID, share doesn't exist.");
 	}
 
 	/**
 	 * @param array $share Share with info from the share_external table
-	 * @return enriched share info with data from the filecache
+	 * @return array enriched share info with data from the filecache
 	 */
 	private static function extendShareInfo($share) {
 		$view = new \OC\Files\View('/' . \OC_User::getUser() . '/files/');

apps/files_sharing/lib/external/manager.php

@@ -194,7 +194,7 @@ class Manager {
 
 			\OC_Hook::emit('OCP\Share', 'federated_share_added', ['server' => $share['remote']]);
 
-			$this->scrapNotification($id);
+			$this->processNotification($id);
 			return true;
 		}
 
@@ -217,7 +217,7 @@ class Manager {
 			$removeShare->execute(array($id, $this->uid));
 			$this->sendFeedbackToRemote($share['remote'], $share['share_token'], $share['remote_id'], 'decline');
 
-			$this->scrapNotification($id);
+			$this->processNotification($id);
 			return true;
 		}
 
@@ -227,7 +227,7 @@ class Manager {
 	/**
 	 * @param int $remoteShare
 	 */
-	protected function scrapNotification($remoteShare) {
+	public function processNotification($remoteShare) {
 		$filter = $this->notificationManager->createNotification();
 		$filter->setApp('files_sharing')
 			->setUser($this->uid)