Create workaround for "identifier of an instance altered"

Related to: #19323

model/jpa/src/main/java/org/keycloak/models/jpa/JpaUserProvider.java

@@ -927,7 +927,16 @@ public class JpaUserProvider implements UserProvider, UserCredentialStore {
         query.setParameter("identityProvider", identityProvider);
         query.setLockMode(lockMode);
         List<FederatedIdentityEntity> results = query.getResultList();
-        return results.size() > 0 ? results.get(0) : null;
+        FederatedIdentityEntity federatedIdentityEntity = results.size() > 0 ? results.get(0) : null;
+        if (federatedIdentityEntity != null) {
+            // When upgrading from Hibernate 5 to Hibernate 6.2.0.CR3, the `user` wasn't filled in the returned row any more.
+            // This serves as a workaround until the cause has been found and the upstream project can provide a fix
+            // https://github.com/keycloak/keycloak/issues/19323
+            if (federatedIdentityEntity.getUser() == null) {
+                federatedIdentityEntity.setUser(userEntity);
+            }
+        }
+        return federatedIdentityEntity;
     }
 
 

model/jpa/src/main/java/org/keycloak/models/jpa/entities/FederatedIdentityEntity.java

@@ -156,6 +156,11 @@ public class FederatedIdentityEntity {
             result = 31 * result + (identityProvider != null ? identityProvider.hashCode() : 0);
             return result;
         }
+
+        @Override
+        public String toString() {
+            return "FederatedIdentityEntity.Key [user=" + (user != null ? user.getId() : null) + ", identityProvider=" + identityProvider + "]";
+        }
     }
 
     @Override