From ba100ec358868a06d0ec540cfd1c631c5aaedcf8 Mon Sep 17 00:00:00 2001
From: Nate Prewitt <Nate.Prewitt@gmail.com>
Date: Thu, 26 Aug 2021 17:37:18 -0700
Subject: [PATCH] Appropriately handle urllib3's InvalidHeader exception

---
 requests/adapters.py   |  5 ++++-
 tests/test_lowlevel.py | 27 +++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/requests/adapters.py b/requests/adapters.py
index fa4d9b3cc9..9b7f92af66 100644
--- a/requests/adapters.py
+++ b/requests/adapters.py
@@ -19,6 +19,7 @@
 from urllib3.exceptions import ClosedPoolError
 from urllib3.exceptions import ConnectTimeoutError
 from urllib3.exceptions import HTTPError as _HTTPError
+from urllib3.exceptions import InvalidHeader as _InvalidHeader
 from urllib3.exceptions import MaxRetryError
 from urllib3.exceptions import NewConnectionError
 from urllib3.exceptions import ProxyError as _ProxyError
@@ -37,7 +38,7 @@
 from .cookies import extract_cookies_to_jar
 from .exceptions import (ConnectionError, ConnectTimeout, ReadTimeout, SSLError,
                          ProxyError, RetryError, InvalidSchema, InvalidProxyURL,
-                         InvalidURL)
+                         InvalidURL, InvalidHeader)
 from .auth import _basic_auth_str
 
 try:
@@ -527,6 +528,8 @@ def send(self, request, stream=False, timeout=None, verify=True, cert=None, prox
                 raise SSLError(e, request=request)
             elif isinstance(e, ReadTimeoutError):
                 raise ReadTimeout(e, request=request)
+            elif isinstance(e, _InvalidHeader):
+                raise InvalidHeader(e, request=request)
             else:
                 raise
 
diff --git a/tests/test_lowlevel.py b/tests/test_lowlevel.py
index d0fa136a69..88ecf9aa38 100644
--- a/tests/test_lowlevel.py
+++ b/tests/test_lowlevel.py
@@ -46,6 +46,33 @@ def incomplete_chunked_response_handler(sock):
         close_server.set()  # release server block
 
 
+def test_conflicting_content_lengths():
+    """Ensure we correctly throw an InvalidHeader error if multiple
+    conflicting Content-Length headers are returned.
+    """
+
+    def multiple_content_length_response_handler(sock):
+        request_content = consume_socket_content(sock, timeout=0.5)
+
+        # The server never ends the request and doesn't provide any valid chunks
+        sock.send(b"HTTP/1.1 200 OK\r\n" +
+                  b"Content-Type: text/plain\r\n" +
+                  b"Content-Length: 16\r\n" +
+                  b"Content-Length: 32\r\n\r\n" +
+                  b"-- Bad Actor -- Original Content\r\n")
+
+        return request_content
+
+    close_server = threading.Event()
+    server = Server(multiple_content_length_response_handler)
+
+    with server as (host, port):
+        url = 'http://{}:{}/'.format(host, port)
+        with pytest.raises(requests.exceptions.InvalidHeader):
+            r = requests.get(url)
+        close_server.set()
+
+
 def test_digestauth_401_count_reset_on_redirect():
     """Ensure we correctly reset num_401_calls after a successful digest auth,
     followed by a 302 redirect to another digest auth prompt.