Fix form submit messages length

app/bundles/FormBundle/Entity/Form.php

@@ -13,6 +13,7 @@
 
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\DBAL\Types\Type;
+use Doctrine\DBAL\Types\Types;
 use Doctrine\ORM\Mapping as ORM;
 use Mautic\ApiBundle\Serializer\Driver\ApiMetadataDriver;
 use Mautic\CoreBundle\Doctrine\Mapping\ClassMetadataBuilder;
@@ -182,7 +183,7 @@ public static function loadMetadata(ORM\ClassMetadata $metadata)
             ->columnName('post_action')
             ->build();
 
-        $builder->createField('postActionProperty', 'string')
+        $builder->createField('postActionProperty', Types::TEXT)
             ->columnName('post_action_property')
             ->nullable()
             ->build();

app/migrations/Version20210623071326.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * @copyright   <year> Mautic Contributors. All rights reserved.
+ * @author      Mautic
+ * @link        https://mautic.org
+ * @license     GNU/GPLv3 http://www.gnu.org/licenses/gpl-3.0.html
+ */
+
+namespace Mautic\Migrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\Exception\SkipMigration;
+use Mautic\CoreBundle\Doctrine\AbstractMauticMigration;
+
+final class Version20210623071326 extends AbstractMauticMigration
+{
+    public function up(Schema $schema): void
+    {
+        $this->addSql("ALTER TABLE {$this->prefix}forms MODIFY post_action_property LONGTEXT ");
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql("UPDATE {$this->prefix}forms SET post_action_property = left(post_action_property,191)");
+        $this->addSql("ALTER TABLE {$this->prefix}forms MODIFY post_action_property VARCHAR(191) DEFAULT NULL ");
+    }
+}