MDL-71390 core: raise max_input_vars requirement

.github/workflows/push.yml

@@ -88,6 +88,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
+          ini-values: max_input_vars=5000
           coverage: none
 
       - name: Checking out code from ${{ env.GITHUB_REF_SLUG }}

admin/environment.xml

@@ -3527,6 +3527,8 @@
           <ON_CHECK message="sixtyfourbitswarning" />
         </FEEDBACK>
       </CUSTOM_CHECK>
+      <CUSTOM_CHECK file="lib/upgradelib.php" function="check_max_input_vars" level="optional">
+      </CUSTOM_CHECK>
     </CUSTOM_CHECKS>
   </MOODLE>
 </COMPATIBILITY_MATRIX>

lang/en/admin.php

@@ -1197,6 +1197,8 @@ $string['sessiontimeout'] = 'Timeout';
 $string['sessiontimeoutwarning'] = 'Timeout Warning';
 $string['settingdependenton'] = 'This setting may be hidden, based on the value of <strong>{$a}</strong>.';
 $string['settingfileuploads'] = 'File uploading is required for normal operation, please enable it in PHP configuration.';
+$string['settingmaxinputvars'] = 'PHP setting max_input_vars is recommended to be at least 5000.';
+$string['settingmaxinputvarsrequired'] = 'PHP setting max_input_vars must be at least 5000.';
 $string['settingmemorylimit'] = 'Insufficient memory detected, please set higher memory limit in PHP settings.';
 $string['settingsafemode'] = 'Moodle is not fully compatible with safe mode, please ask server administrator to turn it off. Running Moodle under safe mode is not supported, please expect various problems if you do so.';
 $string['setupsearchengine'] = 'Setup search engine';

lib/tests/behat/largeforms.feature

@@ -28,39 +28,6 @@ Feature: Forms with a large number of fields
     And I should see "submitbutton=Submit here!"
     And I should see "Bulk checkbox success: true"
 
-  @javascript
-  Scenario: Medium length form with checkboxes (needs workaround)
-    When I follow "Advanced checkboxes / Below limit"
-    And I press "Submit here!"
-    Then I should see "_qf__core_max_input_vars_form=1"
-    And I should see "mform_isexpanded_id_general=1"
-    And I should see "arraytest=[13,42]"
-    And I should see "array2test=[13,42]"
-    And I should see "submitbutton=Submit here!"
-    And I should see "Bulk checkbox success: true"
-
-  @javascript
-  Scenario: Exact PHP limit length form with checkboxes (uses workaround but doesn't need it)
-    When I follow "Advanced checkboxes / Exact PHP limit"
-    And I press "Submit here!"
-    Then I should see "_qf__core_max_input_vars_form=1"
-    And I should see "mform_isexpanded_id_general=1"
-    And I should see "arraytest=[13,42]"
-    And I should see "array2test=[13,42]"
-    And I should see "submitbutton=Submit here!"
-    And I should see "Bulk checkbox success: true"
-
-  @javascript
-  Scenario: Longer than the limit with checkboxes (needs workaround)
-    When I follow "Advanced checkboxes / Above limit"
-    And I press "Submit here!"
-    Then I should see "_qf__core_max_input_vars_form=1"
-    And I should see "mform_isexpanded_id_general=1"
-    And I should see "arraytest=[13,42]"
-    And I should see "array2test=[13,42]"
-    And I should see "submitbutton=Submit here!"
-    And I should see "Bulk checkbox success: true"
-
   @javascript
   Scenario: Small form with array fields (not using workaround)
     When I follow "Select options / Small"
@@ -93,14 +60,3 @@ Feature: Forms with a large number of fields
     And I should see "array2test=[13,42]"
     And I should see "submitbutton=Submit here!"
     And I should see "Bulk array success: true"
-
-  @javascript
-  Scenario: Longer than the limit with array fields (needs workaround)
-    When I follow "Select options / Above limit"
-    And I press "Submit here!"
-    Then I should see "_qf__core_max_input_vars_form=1"
-    And I should see "mform_isexpanded_id_general=1"
-    And I should see "arraytest=[13,42]"
-    And I should see "array2test=[13,42]"
-    And I should see "submitbutton=Submit here!"
-    And I should see "Bulk array success: true"

lib/tests/fixtures/max_input_vars.php

@@ -112,9 +112,6 @@ if ($type) {
         } else {
             $fieldcount = (int)ini_get('max_input_vars') - 11;
         }
-    } else if ($type[1] === 'l') {
-        // Just over the limit.
-        $fieldcount = (int)ini_get('max_input_vars') + 100;
     }
 
     $mform = new core_max_input_vars_form('max_input_vars.php',
@@ -220,8 +217,7 @@ if ($type && ($result = $mform->get_data())) {
 echo html_writer::start_tag('ul');
 foreach (array('c' => 'Advanced checkboxes',
         'a' => 'Select options') as $control => $controlname) {
-    foreach (array('s' => 'Small', 'm' => 'Below limit', 'e' => 'Exact PHP limit',
-            'l' => 'Above limit') as $size => $sizename) {
+    foreach (array('s' => 'Small', 'm' => 'Below limit', 'e' => 'Exact PHP limit') as $size => $sizename) {
         echo html_writer::tag('li', html_writer::link('max_input_vars.php?type=' .
                 $control . $size, $controlname . ' / ' . $sizename));
     }

lib/upgradelib.php

@@ -2624,3 +2624,27 @@ function check_libcurl_version(environment_results $result) {
 
     return null;
 }
+
+/**
+ * Environment check for the php setting max_input_vars
+ *
+ * @param environment_results $result
+ * @return environment_results|null
+ */
+function check_max_input_vars(environment_results $result) {
+    $max = (int)ini_get('max_input_vars');
+    if ($max < 5000) {
+        $result->setInfo('max_input_vars');
+        $result->setStatus(false);
+        if (PHP_VERSION_ID >= 80000) {
+            // For PHP8 this check is required.
+            $result->setLevel('required');
+            $result->setFeedbackStr('settingmaxinputvarsrequired');
+        } else {
+            // For PHP7 this check is optional (recommended).
+            $result->setFeedbackStr('settingmaxinputvars');
+        }
+        return $result;
+    }
+    return null;
+}