Merge branch '4.4' into 5.1

* 4.4:
  [FrameworkBundle] generate preload.php in src/ to make opcache.preload predictable

Author: fabpot

Command/CacheClearCommand.php

@@ -175,6 +175,20 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             }
         }
 
+        $kernelDir = \dirname((new \ReflectionObject($kernel))->getFileName());
+        $preloadFile = $fs->makePathRelative(\dirname($containerFile, 2), $kernelDir);
+        $preloadFile .= substr_replace(basename($containerFile), '.preload', -4, 0);
+        $preloadFile = var_export('/'.$preloadFile, true);
+        @file_put_contents($kernelDir.'/preload.php', <<<EOPHP
+<?php
+
+if (file_exists(__DIR__.$preloadFile)) {
+    require __DIR__.$preloadFile;
+}
+
+EOPHP
+        );
+
         if ($output->isVerbose()) {
             $io->comment('Finished');
         }

Tests/Command/CacheClearCommand/CacheClearCommandTest.php

@@ -38,6 +38,7 @@ protected function setUp(): void
     protected function tearDown(): void
     {
         $this->fs->remove($this->kernel->getProjectDir());
+        $this->fs->remove(__DIR__.'/Fixture/preload.php');
     }
 
     public function testCacheIsFreshAfterCacheClearedWithWarmup()
@@ -82,5 +83,7 @@ public function testCacheIsFreshAfterCacheClearedWithWarmup()
         $containerRef = new \ReflectionClass(require $containerFile);
         $containerFile = str_replace('tes_'.\DIRECTORY_SEPARATOR, 'test'.\DIRECTORY_SEPARATOR, $containerRef->getFileName());
         $this->assertMatchesRegularExpression(sprintf('/\'kernel.container_class\'\s*=>\s*\'%s\'/', $containerClass), file_get_contents($containerFile), 'kernel.container_class is properly set on the dumped container');
+
+        $this->assertFileEquals(__DIR__.'/Fixture/preload.php.expected', __DIR__.'/Fixture/preload.php');
     }
 }

Tests/Command/CacheClearCommand/Fixture/preload.php.expected

@@ -0,0 +1,5 @@
+<?php
+
+if (file_exists(__DIR__.'/test/var/cache/test/FixtureSymfony_Bundle_FrameworkBundle_Tests_Command_CacheClearCommand_Fixture_TestAppKernelTestDebugContainer.preload.php')) {
+    require __DIR__.'/test/var/cache/test/FixtureSymfony_Bundle_FrameworkBundle_Tests_Command_CacheClearCommand_Fixture_TestAppKernelTestDebugContainer.preload.php';
+}