[HttpFoundation] use atomic writes in MockFileSessionStorage

symfony · nicolas-grekas · Jan 14, 2021 · Jan 13, 2021 · Jan 13, 2021 · 5290e978bdb8cdd66290d1344d57f088227db31a
commit 5290e978bdb8cdd66290d1344d57f088227db31a
diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php b/src/Symfony/Component/HttpFoundation/Session/Storage/MockFileSessionStorage.php
@@ -103,7 +103,10 @@ public function save()

        try {
            if ($data) {
-                file_put_contents($this->getFilePath(), serialize($data));
+                $path = $this->getFilePath();
+                $tmp = $path.bin2hex(random_bytes(6));
+                file_put_contents($tmp, serialize($data));
+                rename($tmp, $path);
            } else {
                $this->destroy();
            }
@@ -123,8 +126,11 @@ public function save()
     */
    private function destroy(): void
    {
-        if (is_file($this->getFilePath())) {
+        set_error_handler(static function () {});
+        try {
            unlink($this->getFilePath());
+        } finally {
+            restore_error_handler();
        }
    }

@@ -141,8 +147,14 @@ private function getFilePath(): string
     */
    private function read(): void
    {
-        $filePath = $this->getFilePath();
-        $this->data = is_readable($filePath) && is_file($filePath) ? unserialize(file_get_contents($filePath)) : [];
+        set_error_handler(static function () {});
+        try {
+            $data = file_get_contents($this->getFilePath());
+        } finally {
+            restore_error_handler();
+        }
+
+        $this->data = $data ? unserialize($data) : [];

        $this->loadSession();
    }