fix: auto_link() converts invalid string like "://codeigniter.com"

The scheme is missing, so it is not a valid URL.

Author: kenjis

system/Helpers/url_helper.php

@@ -351,7 +351,7 @@ function safe_mailto(string $email, string $title = '', $attributes = ''): strin
     function auto_link(string $str, string $type = 'both', bool $popup = false): string
     {
         // Find and replace any URLs.
-        if ($type !== 'email' && preg_match_all('#(\w*://|www\.)[a-z0-9]+(-+[a-z0-9]+)*(\.[a-z0-9]+(-+[a-z0-9]+)*)+(/([^\s()<>;]+\w)?/?)?#i', $str, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER)) {
+        if ($type !== 'email' && preg_match_all('#([a-z][a-z0-9+\-.]*://|www\.)[a-z0-9]+(-+[a-z0-9]+)*(\.[a-z0-9]+(-+[a-z0-9]+)*)+(/([^\s()<>;]+\w)?/?)?#i', $str, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER)) {
             // Set our target HTML if using popup links.
             $target = ($popup) ? ' target="_blank"' : '';
 

tests/system/Helpers/URLHelper/MiscUrlTest.php

@@ -523,7 +523,7 @@ public static function provideAutoLinkUrl(): iterable
             ],
             'test06' => [
                 'This one: ://codeigniter.com must not break this one: http://codeigniter.com',
-                'This one: <a href="://codeigniter.com">://codeigniter.com</a> must not break this one: <a href="http://codeigniter.com">http://codeigniter.com</a>',
+                'This one: ://codeigniter.com must not break this one: <a href="http://codeigniter.com">http://codeigniter.com</a>',
             ],
             'test07' => [
                 'Visit example.com or email [email protected]',
@@ -623,7 +623,7 @@ public static function provideAutolinkBoth(): iterable
             ],
             'test06' => [
                 'This one: ://codeigniter.com must not break this one: http://codeigniter.com',
-                'This one: <a href="://codeigniter.com">://codeigniter.com</a> must not break this one: <a href="http://codeigniter.com">http://codeigniter.com</a>',
+                'This one: ://codeigniter.com must not break this one: <a href="http://codeigniter.com">http://codeigniter.com</a>',
             ],
             'test07' => [
                 'Visit example.com or email [email protected]',
@@ -675,7 +675,7 @@ public static function provideAutoLinkPopup(): iterable
             ],
             'test06' => [
                 'This one: ://codeigniter.com must not break this one: http://codeigniter.com',
-                'This one: <a href="://codeigniter.com" target="_blank">://codeigniter.com</a> must not break this one: <a href="http://codeigniter.com" target="_blank">http://codeigniter.com</a>',
+                'This one: ://codeigniter.com must not break this one: <a href="http://codeigniter.com" target="_blank">http://codeigniter.com</a>',
             ],
             'test07' => [
                 'Visit example.com or email [email protected]',