fix(config): Throw PreconditionException always when it didn't matchbackport/47933/stable29

Previously even when the precondition did not match, the call "passed"
when the after value was the expected one. This however can lead to
race conditions, duplicate code excutions and other things.

Signed-off-by: Joas Schilling <coding@schilljs.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/private/AllConfig.php b/lib/private/AllConfig.php
index de1c19c953a..f0169fee18d 100644
--- a/lib/private/AllConfig.php
+++ b/lib/private/AllConfig.php
@@ -269,10 +269,10 @@ class AllConfig implements IConfig {
 		$prevValue = $this->getUserValue($userId, $appName, $key, null);
 
 		if ($prevValue !== null) {
-			if ($prevValue === (string)$value) {
-				return;
-			} elseif ($preCondition !== null && $prevValue !== (string)$preCondition) {
+			if ($preCondition !== null && $prevValue !== (string)$preCondition) {
 				throw new PreConditionNotMetException();
+			} elseif ($prevValue === (string)$value) {
+				return;
 			} else {
 				$qb = $this->connection->getQueryBuilder();
 				$qb->update('preferences')