bug #37763 Fix deprecated libxml_disable_entity_loader (jderusse)

This PR was merged into the 3.4 branch.

Discussion
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Fix deprecated libxml_disable_entity_loader

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | /
| License       | MIT
| Doc PR        | /

Fix deprecation `Function libxml_disable_entity_loader() is deprecated` triggered by php/php-src#5867 in PHP8

Commits
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1f19da3936 Fix deprecated libxml_disable_entity_loader

Author: fabpot

Loader/XmlFileLoader.php

@@ -620,9 +620,13 @@ public function validateSchema(\DOMDocument $dom)
 EOF
         ;
 
-        $disableEntities = libxml_disable_entity_loader(false);
-        $valid = @$dom->schemaValidateSource($source);
-        libxml_disable_entity_loader($disableEntities);
+        if (LIBXML_VERSION < 20900) {
+            $disableEntities = libxml_disable_entity_loader(false);
+            $valid = @$dom->schemaValidateSource($source);
+            libxml_disable_entity_loader($disableEntities);
+        } else {
+            $valid = @$dom->schemaValidateSource($source);
+        }
 
         foreach ($tmpfiles as $tmpfile) {
             @unlink($tmpfile);

Tests/Loader/XmlFileLoaderTest.php

@@ -95,13 +95,17 @@ public function testParseFile()
 
     public function testLoadWithExternalEntitiesDisabled()
     {
-        $disableEntities = libxml_disable_entity_loader(true);
+        if (LIBXML_VERSION < 20900) {
+            $disableEntities = libxml_disable_entity_loader(true);
+        }
 
         $containerBuilder = new ContainerBuilder();
         $loader = new XmlFileLoader($containerBuilder, new FileLocator(self::$fixturesPath.'/xml'));
         $loader->load('services2.xml');
 
-        libxml_disable_entity_loader($disableEntities);
+        if (LIBXML_VERSION < 20900) {
+            libxml_disable_entity_loader($disableEntities);
+        }
 
         $this->assertGreaterThan(0, $containerBuilder->getParameterBag()->all(), 'Parameters can be read from the config file.');
     }