MC-29795: Some environment variables do not lock the settings in the backend

Author: dyushkin

app/code/Magento/Config/Block/System/Config/Form/Field.php

@@ -98,7 +98,7 @@ protected function _renderInheritCheckbox(\Magento\Framework\Data\Form\Element\A
         $htmlId = $element->getHtmlId();
         $namePrefix = preg_replace('#\[value\](\[\])?$#', '', $element->getName());
         $checkedHtml = $element->getInherit() == 1 ? 'checked="checked"' : '';
-        $disabled = $element->getIsDisableInheritance() == true ? ' disabled="disabled"' : '';
+        $disabled = $element->getIsDisableInheritance() == true ? ' disabled="disabled" readonly="1"' : '';
 
         $html = '<td class="use-default">';
         $html .= '<input id="' .

app/code/Magento/Config/Test/Unit/Block/System/Config/Form/FieldTest.php

@@ -187,7 +187,7 @@ public function testRenderInheritCheckbox()
             '_inherit" name="' .
             $this->_testData['name'] .
             '[inherit]" type="checkbox" value="1"' .
-            ' class="checkbox config-inherit" checked="checked"' . ' disabled="disabled"' .
+            ' class="checkbox config-inherit" checked="checked"' . ' disabled="disabled"' . ' readonly="1"' .
             ' onclick="toggleValueElements(this, Element.previous(this.parentNode))" /> ';
 
         $expected .= '<label for="' . $this->_testData['htmlId'] . '_inherit" class="inherit">Use Website</label>';

lib/web/mage/adminhtml/form.js

@@ -494,7 +494,8 @@ define([
                     inputs.each(function (item) {
                         // don't touch hidden inputs (and Use Default inputs too), bc they may have custom logic
                         if ((!item.type || item.type != 'hidden') && !($(item.id + '_inherit') && $(item.id + '_inherit').checked) && //eslint-disable-line
-                            !(currentConfig['can_edit_price'] != undefined && !currentConfig['can_edit_price']) //eslint-disable-line
+                            !(currentConfig['can_edit_price'] != undefined && !currentConfig['can_edit_price']) && //eslint-disable-line
+                            !item.getAttribute('readonly') //eslint-disable-line
                         ) {
                             item.disabled = false;
                             jQuery(item).removeClass('ignore-validate');