I have found multiple fixes for this issue. We have our Moodle site sitting in a load balanced environment with SSL offloading.
I was running into the same problem as you with HTTPS logins only and certain pages being rewritten as HTTPS which resulted in broken pages.
Here are the fixes we have implemented in our environment to workaround these issues. I would test them with your environment prior to putting them on a production site. This is with Moodle 2.4.7 but I would imagine it applies to more than one version.
1. Set sslproxy=true in config.php file
2. Comment out the following section from /lib/setuplib.php. Approximately line 822 - 828
3. Add the following lines to lib/pagelib.php typically found around line 1352
if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https') {
$_SERVER['HTTPS'] = 'On';
return;
} else {
redirect($this->_url);
}
Use the image below as a guide. You will replace out the return; line with the enclosed code.
4. To prevent form pages from being rewritten as HTTPS you will need to comment out the following lines around line 175 in /lib/formslib.php
/*if (!empty($CFG->sslproxy)) {
// return only https links when using SSL proxy
$action = preg_replace('/^http:/', 'https:', $action, 1);
}*/
