@jjbongio If you check the description of your issue on GitHub you will see that the markup is not visible, e.g. the <div>. Markup or code needs to be quoted with ` to be visible here. I could correct that for you, but I thought it's better if I let you know first. Let me know if you have some questions or if I shall change the description for you.

Thank you for pointing this out. I would appreciate your updating it, as I'm not completely clear on how to escape it properly.

@jjbongio Done. If you edit the description you will see how I have done it.

Got it. Thanks muchly.

I checked that issue yesterday (TBH, not too intensive) but couldn't find any unclosed <div> in the source code of checked pages. For example:

But I gave up to find the code place where the </div> is added.

The same with a close="true". No invalid HTML.

This issue seems to be Joomla 3. I have tested with Joomla 4. But in Joomla 4 it's the same PHP code and no invalid HTML:

return '</div><div ' . $class . '>' . implode('', $html);

I may not have explained it well. The generated HTML is perfectly valid, but it does the wrong thing. The </div> closes an outer div and the <div> starts a new div at the same level as the outer div. What it should do is return a div with the label code in it and close it.
If this isn't clear, I can code an example.

I would say that's on purpose. Because in note fields the label is just a H4 headline and not a real field label. The same for the description.

Yes, the empty divs are not nice in Joomla 3 but I think it would be bigger effort to put the label (= headline) into a div with class="control-label" than to leave it as it is because you have to change CSS, too, or things like that.

As always: I don't have to decide that. But that's for sure not a security issue (or a bug). Joomla 3 is locked for other fixes than these.

Examples from Joomla 3.10.11:

This issue is likely to be related to Joomla 3's fault.

That on purpose as @ReLater already noted. This hacky way works for years, and unlikely will be changed for Joomla 3.10.
However would be nice if someone find a less hacky way to render this field in Joomla 4

I'm not sure I'm describing this correctly (I'm new to the forum, so be patient).
I have a field defined in a form as

<field
name="note1"
type="note"
label="Some Label"
/>

When I use this form in the backend, the returned label is
</div><h4>Some Label<div>

which closes out the containing div.

@jjbongio you described it correctly.
This </div><h4>Some Label<div> is on purpose.

Look the layout file joomla.form.renderfield, it render field label and input, like:

<div class="control-group">
  <div class="control-label"><?php echo $label; ?></div>
  <div class="controls"><?php echo $input; ?></div>
</div>

Now, because we do not want that Note label be inside <div class="control-label">, we do return '</div><div ' . $class . '>' . implode('', $html); in the Note field label, and in result we get:

<div class="control-group">
  <div class="control-label">
    </div><h4>Some Label</h4><div>
  </div>
  <div class="controls"><?php echo $input; ?></div>
</div>

As you can see result markup is correct, even when $field->label return incorect one.

When I use this form in the backend, the returned label is

You probably use it as echo $field->label, try use it as echo $form->renderField($field).
Or add extra wrapper for a Note field on your own: echo '<div>' . $field->label . '</div>';
In this case your form will not be broken.

@jjbongio I have marked your code so that it is visible. I am wondering how you check the source code of your site?

I have added your code in user config.xml and get this:
If your structure is destroyed then the error could be somewhere on your site and produce a side effect here.

I am wondering how you check the source code of your site?

The Inspector not a reliable source, it shows rendered result (by browser) not real markup (from server).
Because Browser may magicaly fix a broken markup, it will looks correct in the Inspector.

And it possible to get a broken markup with Note field. Check my previus comment for details.
When rendering on your own (I mean without use of $form->renderField($field)), example:

<p><?php echo $field->label; ?></p>

It will produce:

<p></div><h4>Some Label</h4><div></p>

It does not happens in core forms, but easily in 3rd extensions in custom form.

@Fedik Yes, it is a custom form, and I am using $field->label

I was looping through $form->getFieldSet() as $field and echoing $field->label and then $field->input
When I changed it to echo $field->renderField (), it worked nicely without closing the parent div.

Thanks to all for your comments.

Spam with external link faking a Joomla site removed.