From 206eed724b425adbe96ccc9f33922a46c458d890 Mon Sep 17 00:00:00 2001
From: Mykhailo Yusko <myusko@protonmail.com>
Date: Thu, 5 Sep 2024 15:40:34 +0300
Subject: [PATCH] fix(multipart): don't share
 MultipartParseOptions._DEFAULT_HANDLERS between instances

---
 falcon/media/multipart.py     |  2 +-
 tests/test_media_multipart.py | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/falcon/media/multipart.py b/falcon/media/multipart.py
index 17a990265..bb5f160b1 100644
--- a/falcon/media/multipart.py
+++ b/falcon/media/multipart.py
@@ -610,4 +610,4 @@ def __init__(self) -> None:
         self.max_body_part_buffer_size = 1024 * 1024
         self.max_body_part_count = 64
         self.max_body_part_headers_size = 8192
-        self.media_handlers = self._DEFAULT_HANDLERS
+        self.media_handlers = self._DEFAULT_HANDLERS.copy()
diff --git a/tests/test_media_multipart.py b/tests/test_media_multipart.py
index 31c7bbff8..e8e62e5af 100644
--- a/tests/test_media_multipart.py
+++ b/tests/test_media_multipart.py
@@ -9,6 +9,7 @@
 from falcon import media
 from falcon import testing
 from falcon.util import BufferedReader
+from falcon.media.multipart import MultipartParseOptions
 
 try:
     import msgpack
@@ -849,3 +850,14 @@ async def deserialize_async(self, stream, content_type, content_length):
 
     assert resp.status_code == 200
     assert resp.json == ['', '0x48']
+
+
+def test_multipart_parse_options_default_handlers_unique():
+    parse_options_one = MultipartParseOptions()
+    parse_options_two = MultipartParseOptions()
+
+    parse_options_one.media_handlers.pop(falcon.MEDIA_JSON)
+
+    assert id(parse_options_one.media_handlers) != id(parse_options_two.media_handlers)
+    assert len(parse_options_one.media_handlers) == 1
+    assert len(parse_options_two.media_handlers) >= 2