Keep header limit changes focused

Author: Kludex

python_multipart/multipart.py

@@ -1062,14 +1062,11 @@ def _internal_write(self, data: bytes, length: int) -> int:
         # Our index defaults to 0.
         i = 0
 
-        def raise_parse_error(msg: str, offset: int) -> None:
-            raise MultipartParseError(msg, offset=offset)
-
         def advance_header_size(amount: int = 1) -> None:
             nonlocal current_header_size
             current_header_size += amount
             if current_header_size > self.max_header_size:
-                raise_parse_error("Maximum header size exceeded", i)
+                raise MultipartParseError("Maximum header size exceeded", offset=i)
 
         # Set a mark.
         def set_mark(name: str) -> None:
@@ -1195,7 +1192,7 @@ def data_callback(name: CallbackName, end_i: int, remaining: bool = False) -> No
                 if c != CR:
                     current_header_count += 1
                     if current_header_count > self.max_header_count:
-                        raise_parse_error("Maximum header count exceeded", i)
+                        raise MultipartParseError("Maximum header count exceeded", offset=i)
                     current_header_size = 0
 
                 # Set a mark of our header field.

tests/test_multipart.py

@@ -1184,20 +1184,13 @@ def test_bad_start_boundary(self) -> None:
 
     def test_multipart_header_count_limit(self) -> None:
         self.make("poc")
-        payload = (
-            b'--poc\r\nContent-Disposition: form-data; name="x"\r\n'
-            + (b"X-A: 1\r\n" * 8)
-        )
+        payload = b'--poc\r\nContent-Disposition: form-data; name="x"\r\n' + (b"X-A: 1\r\n" * 8)
         with self.assertRaisesRegex(MultipartParseError, "Maximum header count exceeded"):
             self.f.write(payload)
 
     def test_multipart_header_size_limit(self) -> None:
         self.make("poc")
-        payload = (
-            b'--poc\r\nContent-Disposition: form-data; name="x"\r\n'
-            + b"X-A: "
-            + (b"a" * (4096 + 124))
-        )
+        payload = b'--poc\r\nContent-Disposition: form-data; name="x"\r\n' + b"X-A: " + (b"a" * (4096 + 124))
         with self.assertRaisesRegex(MultipartParseError, "Maximum header size exceeded"):
             self.f.write(payload)