Merge branch '4.4' into 5.4

* 4.4:
  [HttpKernel] lock when writting profiles
  Using identical comparison for path validation
  [Mime] Fix email rendering when having inlined parts that are not related to the content
  [HttpFoundation] move flushing outside of Response::closeOutputBuffers
  [FrameworkBundle] Do not throw when describing a factory definition
  Fix checking result of DateTime::getLastErrors

Author: nicolas-grekas

Profiler/FileProfilerStorage.php

@@ -115,19 +115,7 @@ public function purge()
      */
     public function read(string $token): ?Profile
     {
-        if (!$token || !file_exists($file = $this->getFilename($token))) {
-            return null;
-        }
-
-        if (\function_exists('gzcompress')) {
-            $file = 'compress.zlib://'.$file;
-        }
-
-        if (!$data = unserialize(file_get_contents($file))) {
-            return null;
-        }
-
-        return $this->createProfileFromData($token, $data);
+        return $this->doRead($token);
     }
 
     /**
@@ -169,14 +157,13 @@ public function write(Profile $profile): bool
             'status_code' => $profile->getStatusCode(),
         ];
 
-        $context = stream_context_create();
+        $data = serialize($data);
 
-        if (\function_exists('gzcompress')) {
-            $file = 'compress.zlib://'.$file;
-            stream_context_set_option($context, 'zlib', 'level', 3);
+        if (\function_exists('gzencode')) {
+            $data = gzencode($data, 3);
         }
 
-        if (false === file_put_contents($file, serialize($data), 0, $context)) {
+        if (false === file_put_contents($file, $data, \LOCK_EX)) {
             return false;
         }
 
@@ -291,21 +278,34 @@ protected function createProfileFromData(string $token, array $data, Profile $pa
         }
 
         foreach ($data['children'] as $token) {
-            if (!$token || !file_exists($file = $this->getFilename($token))) {
-                continue;
+            if (null !== $childProfile = $this->doRead($token, $profile)) {
+                $profile->addChild($childProfile);
             }
+        }
 
-            if (\function_exists('gzcompress')) {
-                $file = 'compress.zlib://'.$file;
-            }
+        return $profile;
+    }
 
-            if (!$childData = unserialize(file_get_contents($file))) {
-                continue;
-            }
+    private function doRead($token, Profile $profile = null): ?Profile
+    {
+        if (!$token || !file_exists($file = $this->getFilename($token))) {
+            return null;
+        }
+
+        $h = fopen($file, 'r');
+        flock($h, \LOCK_SH);
+        $data = stream_get_contents($h);
+        flock($h, \LOCK_UN);
+        fclose($h);
 
-            $profile->addChild($this->createProfileFromData($token, $childData, $profile));
+        if (\function_exists('gzdecode')) {
+            $data = @gzdecode($data) ?: $data;
         }
 
-        return $profile;
+        if (!$data = unserialize($data)) {
+            return null;
+        }
+
+        return $this->createProfileFromData($token, $data, $profile);
     }
 }