Add the httpsrequired() function to be 100% SSL in some pages.

Merged from MOODLE_15_STABLE

lib/moodlelib.php

@@ -5958,6 +5958,26 @@ function address_in_subnet($addr, $subnetstr) {
     return $found;
 }
 
+/**
+ * This function sets the $HTTPSPAGEREQUIRED global 
+ * (used in some parts of moodle to change some links)
+ * and calculate the proper wwwroot to be used
+ *
+ * By using this function properly, we can ensure 100% https-ized pages
+ * at our entire discretion (login, forgot_password, change_password)
+ */
+function httpsrequired() {
+
+    global $CFG, $HTTPSPAGEREQUIRED;
+
+    if (!empty($CFG->loginhttps)) {
+        $HTTPSPAGEREQUIRED = true;
+        $CFG->httpswwwroot = str_replace('http', 'https', $CFG->wwwroot);
+    } else {
+        $CFG->httpswwwroot = $CFG->wwwroot;
+    }
+}
+
 /**
  * For outputting debugging info
  *