Custom field Post-help not shown

Post-help of custom fields is not displayed to the user. A help icon is displayed, but clicking on it shows an empty popup.

How to reproduce:

• create a custom field for Contact (or other), and with a post-help message.
• go to a "new contact" form, click on the help icon for that field.

For Activities, I'm also getting a smarty notice, because the

{help}

tries to load the content from CRM/Activity/Form/Activity.hlp (it also does for Contact.hlp, but that file exists, even if it doesn't have the custom-field info).

Might be a link with this comment in CRM/Core/Smarty/plugins/function.help.php :

// Legacy support for old-style $params['text']
// TODO: This is probably no longer used, so remove
$help = '';
if (isset($params['text']))

{ $help = '<div class="crm-help">' . $params['text'] . '</div>'; }