[utils] HTTPHeaderDict: Fix __ior__ (#16930)

Authored by: doe1080

Author: doe1080

test/test_utils.py

@@ -2172,6 +2172,10 @@ def test_http_header_dict(self):
         headers6 = HTTPHeaderDict(a=1, b=2)
         self.assertEqual(pickle.loads(pickle.dumps(headers6)), headers6)
 
+        headers7 = HTTPHeaderDict()
+        headers7 |= {'X-dlp': 'data'}
+        self.assertEqual(headers7.sensitive(), {'X-dlp': 'data'})
+
     def test_extract_basic_auth(self):
         assert extract_basic_auth('http://:foo.bar') == ('http://:foo.bar', None)
         assert extract_basic_auth('http://foo.bar') == ('http://foo.bar', None)

yt_dlp/utils/networking.py

@@ -64,7 +64,7 @@ def __ior__(self, other, /):
             other = other.sensitive()
         if isinstance(other, dict):
             self.update(other)
-            return
+            return self
         return NotImplemented
 
     def __or__(self, other, /) -> typing.Self: