From fb98db7da7c30890ea0298ded185829bb543d86c Mon Sep 17 00:00:00 2001
From: Christoph Wurst <christoph@winzerhof-wurst.at>
Date: Fri, 31 Aug 2018 11:46:00 +0200
Subject: [PATCH] Fix handlng of concurrent inserts of the 2FA provider
 registry DAO

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>
---
 .../Db/ProviderUserAssignmentDao.php          | 29 ++++++-------------
 1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/lib/private/Authentication/TwoFactorAuth/Db/ProviderUserAssignmentDao.php b/lib/private/Authentication/TwoFactorAuth/Db/ProviderUserAssignmentDao.php
index e04512b8575eb..ce03eb096612f 100644
--- a/lib/private/Authentication/TwoFactorAuth/Db/ProviderUserAssignmentDao.php
+++ b/lib/private/Authentication/TwoFactorAuth/Db/ProviderUserAssignmentDao.php
@@ -26,6 +26,7 @@
 
 namespace OC\Authentication\TwoFactorAuth\Db;
 
+use Doctrine\DBAL\Exception\UniqueConstraintViolationException;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
 
@@ -72,25 +73,7 @@ public function getState(string $uid): array {
 	public function persist(string $providerId, string $uid, int $enabled) {
 		$qb = $this->conn->getQueryBuilder();
 
-		$this->conn->beginTransaction();
-		// To prevent duplicate primary key, we have to first check if an INSERT
-		// or UPDATE is required
-		$query = $qb->select('*')
-			->from(self::TABLE_NAME)
-			->where($qb->expr()->eq('provider_id', $qb->createNamedParameter($providerId)))
-			->andWhere($qb->expr()->eq('uid', $qb->createNamedParameter($uid)));
-		$result = $query->execute();
-		$rowCount = count($result->fetchAll());
-		$result->closeCursor();
-
-		if ($rowCount > 0) {
-			// There is an entry -> update it
-			$updateQuery = $qb->update(self::TABLE_NAME)
-				->set('enabled', $qb->createNamedParameter($enabled))
-				->where($qb->expr()->eq('provider_id', $qb->createNamedParameter($providerId)))
-				->andWhere($qb->expr()->eq('uid', $qb->createNamedParameter($uid)));
-			$updateQuery->execute();
-		} else {
+		try {
 			// Insert a new entry
 			$insertQuery = $qb->insert(self::TABLE_NAME)->values([
 				'provider_id' => $qb->createNamedParameter($providerId),
@@ -99,8 +82,14 @@ public function persist(string $providerId, string $uid, int $enabled) {
 			]);
 
 			$insertQuery->execute();
+		} catch (UniqueConstraintViolationException $ex) {
+			// There is already an entry -> update it
+			$updateQuery = $qb->update(self::TABLE_NAME)
+				->set('enabled', $qb->createNamedParameter($enabled))
+				->where($qb->expr()->eq('provider_id', $qb->createNamedParameter($providerId)))
+				->andWhere($qb->expr()->eq('uid', $qb->createNamedParameter($uid)));
+			$updateQuery->execute();
 		}
-		$this->conn->commit();
 
 	}