Fix – Support for https

The widget rendered by the plugin uses only http, and that generates an error if the WordPress site uses https.

How to fix the bug

In file template.php, replace this code:
<form action="http://feedburner.google.com/fb/a/mailverify" method="post" target="popupwindow" onsubmit="window.open('http://feedburner.google.com/fb/a/mailverify?uri=<?php echo $feed; ?>', 'popupwindow', 'scrollbars=yes,width=550,height=520');return true">

with this code
<form action="//feedburner.google.com/fb/a/mailverify" method="post" target="popupwindow" onsubmit="window.open('//feedburner.google.com/fb/a/mailverify?uri=<?php echo $feed; ?>', 'popupwindow', 'scrollbars=yes,width=550,height=520');return true">

Basically, the fix consists in removing the explicit http, so that the Feedburner URL depends on the protocol used on the page.

Tested on our site, http://aelia.co, where we use https on the checkout page.

Notes

• The fix should be applied to backend pages as well, but it’s not as critical there.
• I could not find a Github repository to contribute to. If there is one, please let me know and I will send you a pull request. Thanks.

https://wordpress.org/plugins/feedburner-email-subscription/