MDL-80818 QuickForm: Freeze all elements with the same name

There are some radio buttons in activity Completion Conditions settings
that must be frozen altogether, because all of them have the same name.

lib/pear/HTML/QuickForm.php

@@ -1570,15 +1570,16 @@ class HTML_QuickForm extends HTML_Common {
             $elementList = array_flip($elementList);
         }
 
+        $frozen = [];
         foreach (array_keys($this->_elements) as $key) {
             $name = $this->_elements[$key]->getName();
             if ($this->_freezeAll || isset($elementList[$name])) {
                 $this->_elements[$key]->freeze();
-                unset($elementList[$name]);
+                $frozen[$name] = true;
             }
         }
 
-        if (!empty($elementList)) {
+        if (count($elementList) != count($frozen)) {
             return self::raiseError(null, QUICKFORM_NONEXIST_ELEMENT, null, E_USER_WARNING, "Nonexistant element(s): '" . implode("', '", array_keys($elementList)) . "' in HTML_QuickForm::freeze()", 'HTML_QuickForm_Error', true);
         }
         return true;

lib/pear/readme_moodle.txt

@@ -38,6 +38,7 @@ MDL-77164 - PHPdocs corrections
 MDL-78145 - PHP 8.2 compliance. Added a missing class property that still need to be declared
             to avoid dynamic properties deprecated error warning.
             And also remove the $_elementIdx because it is not needed in Moodle code.
+MDL-80818 - Freezing all elements with the same name (e.g. radio buttons)
 
 Pear
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