fix: prevent adding same alias twice; doctrine does not like it

Author: pmattmann

src/Core/Bridge/Doctrine/Orm/Extension/EagerLoadingExtension.php

@@ -31,6 +31,7 @@
 use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\Mapping\ClassMetadataInfo;
 use Doctrine\ORM\Query\Expr\Join;
+use Doctrine\ORM\Query\Expr\Select;
 use Doctrine\ORM\QueryBuilder;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactoryInterface;
@@ -264,7 +265,7 @@ private function joinRelations(QueryBuilder $queryBuilder, QueryNameGeneratorInt
                     continue;
                 }
             } else {
-                $queryBuilder->addSelect($associationAlias);
+                $this->addSelectOnce($queryBuilder, $associationAlias);
             }
 
             // Avoid recursive joins for self-referencing relations
@@ -296,7 +297,7 @@ private function addSelect(QueryBuilder $queryBuilder, string $entity, string $a
         $entityManager = $queryBuilder->getEntityManager();
         $targetClassMetadata = $entityManager->getClassMetadata($entity);
         if (!empty($targetClassMetadata->subClasses)) {
-            $queryBuilder->addSelect($associationAlias);
+            $this->addSelectOnce($queryBuilder, $associationAlias);
 
             return;
         }
@@ -335,6 +336,17 @@ private function addSelect(QueryBuilder $queryBuilder, string $entity, string $a
         $queryBuilder->addSelect(sprintf('partial %s.{%s}', $associationAlias, implode(',', $select)));
     }
 
+    private function addSelectOnce($queryBuilder, $alias)
+    {
+        $existingSelects = array_reduce($queryBuilder->getDQLPart('select') ?? [], function ($existing, $dqlSelect) {
+            return ($dqlSelect instanceof Select) ? array_merge($existing, $dqlSelect->getParts()) : $existing;
+        }, []);
+
+        if (!\in_array($alias, $existingSelects, true)) {
+            $queryBuilder->addSelect($alias);
+        }
+    }
+
     /**
      * Gets the serializer context.
      *