MDL-76235 core: compare email diversion exceptions case-insensitively.

Co-authored-by: Jan Kristoffer Roth <[email protected]>

lib/moodlelib.php

@@ -5920,7 +5920,7 @@ function email_should_be_diverted($email) {
 
     $patterns = array_map('trim', preg_split("/[\s,]+/", $CFG->divertallemailsexcept, -1, PREG_SPLIT_NO_EMPTY));
     foreach ($patterns as $pattern) {
-        if (preg_match("/$pattern/", $email)) {
+        if (preg_match("/{$pattern}/i", $email)) {
             return false;
         }
     }

lib/tests/moodlelib_test.php

@@ -3426,6 +3426,7 @@ EOF;
                     '[email protected]',
                     '[email protected]',
                     '[email protected]',
+                    '[email protected]',
                 ),
                 true,
             ),
@@ -3435,6 +3436,7 @@ EOF;
                 array(
                     '[email protected]',
                     '[email protected]',
+                    '[email protected]',
                     '[email protected]',
                 ),
                 false,