fixed duplicated emailEntry on SubscriberManager add

Author: Aleksander Koko

core/Model/SubscriberModel.php

@@ -115,6 +115,19 @@ public function getSubscriberById( $id )
         return $result->fetch( \PDO::FETCH_ASSOC );
     }
 
+    public function getSubscriberByEmail( $emailAddress )
+    {
+        $result = $this->db->query(
+            sprintf(
+                "SELECT * FROM %s
+                WHERE email = '%s'",
+                $this->config->getTableName( 'user', true ),
+                $emailAddress
+            )
+        );
+        return $result->fetch( \PDO::FETCH_ASSOC );
+    }
+
     /**
      * Cleanly delete all records of a subscriber from DB
      * @param  int $id ID of subscriber to delete

core/SubscriberManager.php

@@ -135,6 +135,10 @@ public function add( \phpList\Entity\SubscriberEntity $scrEntity )
             throw new \Exception( 'Cannot insert subscriber with invalid email address: "' . $scrEntity->emailAddress . '"' );
         }
 
+        $entity = $this->subscriberModel->getSubscriberByEmail($scrEntity->emailAddress);
+        if($entity["email"] !== null)
+            throw new \Exception("Subscriber with that email already exists");
+
         // Save subscriber to db
         $newSubscriberId = $this->subscriberModel->save(
             $scrEntity->emailAddress