MDL-75889 core: compare domain names in a case-insensitive manner.

As per https://www.rfc-editor.org/rfc/rfc1035#section-3.1

lib/classes/ip_utils.php

@@ -187,8 +187,8 @@ final class ip_utils {
     }
 
     /**
-     * Checks the domain name against a list of allowed domains. The list of allowed domains is may use
-     * wildcards that match {@link is_domain_matching_pattern()}.
+     * Checks the domain name against a list of allowed domains. The list of allowed domains may use wildcards
+     * that match {@see is_domain_matching_pattern()}. Domains are compared in a case-insensitive manner
      *
      * @param  string $domain Domain address
      * @param  array $alloweddomains An array of allowed domains.
@@ -208,7 +208,7 @@ final class ip_utils {
                 // Use of wildcard for possible subdomains.
                 $escapeperiods = str_replace('.', '\.', $alloweddomain);
                 $replacewildcard = str_replace('*', '.*', $escapeperiods);
-                $ultimatepattern = '/' . $replacewildcard . '$/';
+                $ultimatepattern = '/' . $replacewildcard . '$/i';
                 if (preg_match($ultimatepattern, $domain)) {
                     return true;
                 }
@@ -217,7 +217,7 @@ final class ip_utils {
                     continue;
                 }
                 // Strict domain setting.
-                if ($domain === $alloweddomain) {
+                if (strcasecmp($domain, $alloweddomain) === 0) {
                     return true;
                 }
             }

lib/tests/ip_utils_test.php

@@ -14,13 +14,13 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 namespace core;
 
 /**
  * This tests the static helper functions contained in the class '\core\ip_utils'.
  *
  * @package    core
+ * @covers     \core\ip_utils
  * @copyright  2016 Jake Dallimore <[email protected]>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -355,6 +355,7 @@ class ip_utils_test extends \basic_testcase {
     public function data_domain_addresses() {
         return [
             [true, 'example.com'],
+            [true, 'ExAmPle.com'],
             [false, 'sub.example.com'],
             [false, 'example.com.au'],
             [false, ' example.com'], // A space at the front of the domain is invalid.
@@ -362,6 +363,8 @@ class ip_utils_test extends \basic_testcase {
             [false, 'test.example.com'],
             [false, 'moodle.com'],
             [true, 'test.moodle.com'],
+            [true, 'TeSt.moodle.com'],
+            [true, 'test.MoOdLe.com'],
             [false, 'test.moodle.com.au'],
             [true, 'nice.address.per.this.penny-arcade.com'],
             [false, 'normal.per.this.penny-arcade.com.au'],

lib/tests/moodlelib_test.php

@@ -4303,7 +4303,13 @@ EOF;
                 'config' => "\r\n example.com \r\n test.com \r\n",
                 'result' => true
             ],
-
+            [
+                'email' => '[email protected]',
+                'display' => \core_user::MAILDISPLAY_EVERYONE,
+                'samecourse' => false,
+                'config' => "example.com\r\ntest.com",
+                'result' => true,
+            ],
             // Test from email is not in allowed domain.
             // Test that from display is set to show no one.
             [   'email' => '[email protected]',