[ticket/12960] Add incomplete captcha to prevent registration

PHPBB3-12960

phpBB/phpbb/captcha/plugins/incomplete.php

@@ -0,0 +1,66 @@
+<?php
+
+namespace phpbb\captcha\plugins;
+
+use phpbb\config\config;
+use phpbb\template\template;
+
+class incomplete extends \phpbb\captcha\plugins\captcha_abstract
+{
+	public function __construct(protected config $config, protected template $template,
+								protected string $phpbb_root_path, protected string $phpEx)
+	{}
+
+	public function is_available()
+	{
+		return true;
+	}
+
+	public function get_generator_class()
+	{
+	}
+
+	public static function get_name()
+	{
+		return 'CAPTCHA_INCOMPLETE';
+	}
+
+	public function init($type)
+	{
+	}
+
+	public function execute_demo()
+	{
+	}
+
+	public function execute()
+	{
+	}
+
+	public function get_demo_template($id)
+	{
+		return '';
+	}
+
+	public function get_template()
+	{
+		$contact_link = phpbb_get_board_contact_link($this->config, $this->phpbb_root_path, $this->phpEx);
+
+		$this->template->assign_vars([
+			'CONFIRM_LANG'	=> $this->type != CONFIRM_POST ? 'CONFIRM_INCOMPLETE' : 'POST_CONFIRM_INCOMPLETE',
+			'CONTACT_LINK'	=> $contact_link,
+		]);
+
+		return 'captcha_incomplete.html';
+	}
+
+	public function validate()
+	{
+		return false;
+	}
+
+	public function is_solved()
+	{
+		return false;
+	}
+}