Get host by name import modifier broken when lookup fails

[rhld-linux]

Expected Behavior

the "Get host by name (DNS lookup)" modifer in an import source shall obey the "On failure" setting and in our case keep the hostname given even if ( or espacially when ) the named can't be looked up

Current Behavior

import preview shows an error; import fails

inet_pton(): Unrecognized address OUR-HOST-NAME-HERE (PropertyModifierGetHostByName.php:37)
#0 [internal function]: Icinga\Application\ApplicationBootstrap->Icinga\Application\{closure}(2, 'inet_pton(): Un...', '/usr/share/icin...', 37, Array)
#1 /usr/share/icingaweb2/modules/director/library/Director/PropertyModifier/PropertyModifierGetHostByName.php(37): inet_pton('OUR-HOST-NAME-HERE')
#2 /usr/share/icingaweb2/modules/director/library/Director/Objects/ImportSource.php(338): Icinga\Module\Director\PropertyModifier\PropertyModifierGetHostByName->transform('OUR-HOST-NAME-HERE')
#3 /usr/share/icingaweb2/modules/director/library/Director/Objects/ImportSource.php(265): Icinga\Module\Director\Objects\ImportSource->applyPropertyModifierToRow(Object(Icinga\Module\Director\PropertyModifier\PropertyModifierGetHostByName), 'object_name', Object(stdClass))
#4 /usr/share/icingaweb2/modules/director/library/Director/Web/Table/ImportsourceHookTable.php(102): Icinga\Module\Director\Objects\ImportSource->applyModifiers(Array)
#5 /usr/share/icingaweb2/modules/incubator/vendor/gipfl/icingaweb2/src/Table/SimpleQueryBasedTable.php(29): Icinga\Module\Director\Web\Table\ImportsourceHookTable->prepareQuery()
#6 /usr/share/icingaweb2/modules/incubator/vendor/gipfl/icingaweb2/src/Table/SimpleQueryBasedTable.php(15): gipfl\IcingaWeb2\Table\SimpleQueryBasedTable->getQuery()
#7 /usr/share/icingaweb2/modules/incubator/vendor/gipfl/icingaweb2/src/Table/QueryBasedTable.php(59): gipfl\IcingaWeb2\Table\SimpleQueryBasedTable->getPaginationAdapter()
#8 /usr/share/icingaweb2/modules/incubator/vendor/gipfl/icingaweb2/src/Table/QueryBasedTable.php(258): gipfl\IcingaWeb2\Table\QueryBasedTable->getPaginator(Object(gipfl\IcingaWeb2\Url))
#9 /usr/share/icingaweb2/modules/director/application/controllers/ImportsourceController.php(185): gipfl\IcingaWeb2\Table\QueryBasedTable->renderTo(Object(Icinga\Module\Director\Controllers\ImportsourceController))
#10 /usr/share/icinga-php/vendor/vendor/shardj/zf1-future/library/Zend/Controller/Action.php(516): Icinga\Module\Director\Controllers\ImportsourceController->previewAction()
#11 /usr/share/php/Icinga/Web/Controller/Dispatcher.php(76): Zend_Controller_Action->dispatch('previewAction')
#12 /usr/share/icinga-php/vendor/vendor/shardj/zf1-future/library/Zend/Controller/Front.php(954): Icinga\Web\Controller\Dispatcher->dispatch(Object(Icinga\Web\Request), Object(Icinga\Web\Response))
#13 /usr/share/php/Icinga/Application/Web.php(294): Zend_Controller_Front->dispatch(Object(Icinga\Web\Request), Object(Icinga\Web\Response))
#14 /usr/share/php/Icinga/Application/webrouter.php(105): Icinga\Application\Web->dispatch()
#15 /usr/share/icingaweb2/public/index.php(4): require_once('/usr/share/php/...')
#16 {main}

Possible Solution

as the inet_pton fails because gethostbyname returns the name it was called to look up when no record exists which then fails our workaround is to edit library/Director/PropertyModifier/PropertyModifierGetHostByName.php like this

        $host = gethostbyname($value);
+	if ($host !== $value) {
+		$inAddr = inet_pton($host);
-	$inAddr = inet_pton($host);
+	} else {
+		$inAddr = "$host";
+	}
        if (! $inAddr || strlen($inAddr) !== 4) {

so the inet_pton function is only called when the gethostbyname did a resolution

Steps to Reproduce (for bugs)

• create an import source in director which import some kind of hosts
• add a modifier to have one fields content be resolved to an IP address
• make sure not all field values actually have a DNS A record set up

Your Environment

• Director version (System - About): 1.11.1
• Icinga Web 2 version and modules (System - About): 2.12.1
• Icinga 2 version (icinga2 --version): 2.14.2-1
• Operating System and version:
• Webserver, PHP versions: apache-2.4.37-62.0.1, php-7.2.24-1