Fix urllib bug in vendored library (#1785)

* Fix urllib bug in vendored library

* changelog updates

Author: sfc-gh-aalam

DESCRIPTION.md

@@ -15,6 +15,7 @@ Source code is also available at: https://github.com/snowflakedb/snowflake-conne
   - Added the `backoff_policy` argument to `snowflake.connector.connect` allowing for configurable backoff policy between retries of failed requests. See available implementations in the `backoff_policies` module.
   - Added the `socket_timeout` argument to `snowflake.connector.connect` specifying socket read and connect timeout.
   - Fixed `login_timeout` and `network_timeout` behaviour. Retries of login and network requests are now properly halted after these timeouts expire.
+  - Fixed bug for issue https://github.com/urllib3/urllib3/issues/1878 in vendored `urllib`.
 
 - v3.3.1(October 16,2023)
 

src/snowflake/connector/vendored/urllib3/util/connection.py

@@ -23,6 +23,13 @@ def is_connection_dropped(conn):  # Platform-specific
         return False
     if sock is None:  # Connection already closed (such as by httplib).
         return True
+    # See issue for more context: https://github.com/urllib3/urllib3/issues/1878
+    # the maintainers know that this issue can be resolve using the change below but
+    # they have not merged this change because they need to root-cause it. See
+    # comment: https://github.com/urllib3/urllib3/issues/1878#issuecomment-641548977
+    # adding the fix in our vendored code so our users get unblocked
+    if getattr(sock, "fileno", lambda _: None)() == -1:
+        return True
     try:
         # Returns True if readable, which here means it's been dropped
         return wait_for_read(sock, timeout=0.0)

test/integ/test_vendored_urllib.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+#
+# Copyright (c) 2012-2023 Snowflake Computing Inc. All rights reserved.
+#
+
+import pytest
+
+try:
+    from snowflake.connector.vendored import urllib3
+
+    vendored_imported = True
+except ModuleNotFoundError:
+    vendored_imported = False
+
+
+@pytest.mark.skipif(
+    not vendored_imported, reason="vendored library is not imported for old driver"
+)
+def test_local_fix_for_closed_socket_bug():
+    # https://github.com/urllib3/urllib3/issues/1878#issuecomment-641534573
+    http = urllib3.PoolManager(maxsize=1)
+
+    def _execute_request():
+        resp = http.request(
+            method="GET", url="http://httpbin.org", preload_content=False
+        )
+        resp._connection.sock.close()
+        resp.release_conn()
+        resp.close()
+        return resp
+
+    _execute_request()
+    try:
+        _execute_request()
+    except ValueError as e:
+        if "file descriptor cannot be a negative" in str(e):
+            raise AssertionError(
+                "Second _execute_request failed. See linked github issue comment"
+            )
+        else:
+            raise e