From 84fd81e33f9334f13d4912edf79570131dd18939 Mon Sep 17 00:00:00 2001
From: Morris Jobke <hey@morrisjobke.de>
Date: Mon, 12 Nov 2018 17:36:35 +0100
Subject: [PATCH] Fix UniqueConstraintViolationException while insert into
 oc_groups

* fixes race condition in insert
* fixes potentiaol deadlock

Signed-off-by: Morris Jobke <hey@morrisjobke.de>
---
 lib/private/Group/Database.php | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/lib/private/Group/Database.php b/lib/private/Group/Database.php
index c77ae9e2ee..c6599839a7 100644
--- a/lib/private/Group/Database.php
+++ b/lib/private/Group/Database.php
@@ -41,6 +41,7 @@
 
 namespace OC\Group;
 
+use Doctrine\DBAL\Exception\UniqueConstraintViolationException;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\Group\Backend\ABackend;
 use OCP\Group\Backend\IAddToGroupBackend;
@@ -97,10 +98,15 @@ class Database extends ABackend
 	public function createGroup(string $gid): bool {
 		$this->fixDI();
 
-		// Add group
-		$result = $this->dbConn->insertIfNotExist('*PREFIX*groups', [
-			'gid' => $gid,
-		]);
+		try {
+			// Add group
+			$builder = $this->dbConn->getQueryBuilder();
+			$result = $builder->insert('groups')
+				->setValue('gid', $builder->createNamedParameter($gid))
+				->execute();
+		} catch(UniqueConstraintViolationException $e) {
+			$result = 0;
+		}
 
 		// Add to cache
 		$this->groupCache[$gid] = $gid;