Invalid returned HTML with multiple required checkboxes

Hello,

in version 2.4.0 and 2.4.1 there is bug with processing multiple required checkboxes.

in simplr_build_form function in simplr_form_functions.php at 369 line:

if(isset($data[$cf['key']])) {
...
$key_val = $data[$cf['key']];
}

you are checking if value is posted and present in dictionary, but you don’t reset value of $key_val between multiple fields, that means if you check on checkbox all next checkboxes will be returned with invalid markup after validation.

Proposed change:
Add

else {
   $key_val = '';
}

Or
Create checkboxes with another hidden field.

<input type="hidden" name="test" val="">
<inputy type="checkbox" name="test" val="on">

This ensures that there is always posted value, even if checkbox is not checked. Because browsers doesn’t send value for unchecked fields.

Proof screenshots:
https://i.imgur.com/TdcDUBc.png
https://i.imgur.com/xKMoct6.png – checked only first field, returned form has all checkboxes checked
https://i.imgur.com/xbNmT8U.png – checked only second field, returned form has all next checkboxes checked