fix: set_radio() implementation

system/Helpers/form_helper.php

@@ -650,14 +650,21 @@ function set_radio(string $field, string $value = '', bool $default = false): st
  $request = Services::request();
 
  // Try any old input data we may have first
- $input = $request->getOldInput($field);
- if ($input === null) {
- $input = $request->getPost($field) ?? $default;
+ $oldInput = $request->getOldInput($field);
+
+ $postInput = $request->getPost($field);
+
+ if ($oldInput !== null) {
+ $input = $oldInput;
+ } elseif ($postInput !== null) {
+ $input = $postInput;
+ } else {
+ $input = $default;
  }
 
  if (is_array($input)) {
  // Note: in_array('', array(0)) returns TRUE, do not use it
- foreach ($input as &$v) {
+ foreach ($input as $v) {
  if ($value === $v) {
  return ' checked="checked"';
  }
@@ -667,16 +674,11 @@ function set_radio(string $field, string $value = '', bool $default = false): st
  }
 
  // Unchecked checkbox and radio inputs are not even submitted by browsers ...
- $result = '';
- if ((string) $input === '0' || ! empty($input = $request->getPost($field)) || ! empty($input = old($field))) {
- $result = ($input === $value) ? ' checked="checked"' : '';
- }
-
- if (empty($result)) {
- $result = ($default === true) ? ' checked="checked"' : '';
+ if ($oldInput !== null || $postInput !== null) {
+ return ((string) $input === $value) ? ' checked="checked"' : '';
  }
 
- return $result;
+ return ($default === true) ? ' checked="checked"' : '';
  }
 }