Acquire a lock when updating elements via GraphQL

Fixes #14113

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Fixed a bug where the “Save and add another” element action wasn’t redirecting to a new element edit page, when editing an unpublished draft.
 - Fixed a bug where `craft\helpers\DateTimeHelper::nextYear()` and `lastYear()` weren’t returning the correct dates. ([#14109](https://github.com/craftcms/cms/issues/14109))
 - Fixed a bug where image transforms weren’t getting created for remote assets, if `maxCachedCloudImageSize` was set to `0`. ([#14100](https://github.com/craftcms/cms/issues/14100))
+- Fixed a SQL error that could occur when updating existing elements via GraphQL mutations. ([#14113](https://github.com/craftcms/cms/issues/14113))
 
 ## 4.5.14 - 2024-01-02
 

src/gql/base/ElementMutationResolver.php

@@ -18,6 +18,7 @@
 use GraphQL\Type\Definition\ResolveInfo;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\WrappingType;
+use yii\web\ServerErrorHttpException;
 
 /**
  * Class MutationResolver
@@ -160,7 +161,22 @@ protected function saveElement(ElementInterface $element): ElementInterface
             $element->setScenario(Element::SCENARIO_LIVE);
         }
 
-        Craft::$app->getElements()->saveElement($element);
+        $isNotNew = $element->id;
+        if ($isNotNew) {
+            $lockKey = "element:$element->id";
+            $mutex = Craft::$app->getMutex();
+            if (!$mutex->acquire($lockKey, 15)) {
+                throw new ServerErrorHttpException('Could not acquire a lock to save the element.');
+            }
+        }
+
+        try {
+            Craft::$app->getElements()->saveElement($element);
+        } finally {
+            if ($isNotNew) {
+                $mutex->release($lockKey);
+            }
+        }
 
         if ($element->hasErrors()) {
             $validationErrors = [];