Fix broken signup

- Fix php error when user clicks signup.
- Revert change to `auth_can_change_password` custom function.

Fixes #22744

core/authentication_api.php

@@ -257,14 +257,7 @@ function auth_can_set_password( $p_user_id = null ) {
 		return false;
 	}
 
-	$t_can_change = array(
-		PLAIN,
-		CRYPT,
-		CRYPT_FULL_SALT,
-		MD5,
-	);
-
-	return in_array( config_get( 'login_method' ), $t_can_change );
+	return helper_call_custom_function( 'auth_can_change_password', array() );
 }
 
 /**

core/custom_function_api.php

@@ -269,7 +269,14 @@ function custom_function_default_issue_delete_notify( $p_issue_id ) {
  * @return boolean
  */
 function custom_function_default_auth_can_change_password() {
-	return auth_can_set_password();
+	$t_can_change = array(
+		PLAIN,
+		CRYPT,
+		CRYPT_FULL_SALT,
+		MD5,
+	);
+
+	return in_array( config_get( 'login_method' ), $t_can_change );
 }
 
 /**

signup.php

@@ -72,7 +72,7 @@
 }
 
 if( ON == config_get( 'signup_use_captcha' ) && get_gd_version() > 0 &&
-	auth_can_set_password( NO_USER ) ) {
+	helper_call_custom_function( 'auth_can_change_password', array() ) ) {
 	# captcha image requires GD library and related option to ON
 	require_lib( 'securimage/securimage.php' );
 

signup_page.php

@@ -103,7 +103,7 @@
 			</label>
 
 <?php
-	$t_allow_passwd_change = auth_can_set_password( NO_USER );
+	$t_allow_passwd_change = helper_call_custom_function( 'auth_can_change_password', array() );
 
 	# captcha image requires GD library and related option to ON
 	if( ON == config_get( 'signup_use_captcha' ) && get_gd_version() > 0 && $t_allow_passwd_change ) {
@@ -141,10 +141,11 @@
 
 <?php
 			}
+
 			if( !$t_allow_passwd_change ) {
 				echo '<div class="space-10"></div>';
 				echo '<div class="alert alert-danger">';
-				echo auth_password_managed_elsewhere_message();
+				echo lang_get( 'no_password_change' );;
 				echo '</div>';
 			}
 ?>