PYTHON-5297 [v4.12] AsyncMongoClient connection error causes UnboundLocalError (#2277)

Co-authored-by: Noah Stapp <noah.stapp@mongodb.com>

Author: blink1073

doc/changelog.rst

@@ -6,16 +6,16 @@ Changes in Version 4.12.1 (XXXX/XX/XX)
 
 Version 4.12.1 is a bug fix release.
 
+- Fixed a bug that could raise ``UnboundLocalError`` when creating asynchronous connections over SSL.
 - Fixed a bug causing SRV hostname validation to fail when resolver and resolved hostnames are identical with three domain levels.
 
 Issues Resolved
 ...............
 
-See the `PyMongo 4.12 release notes in JIRA`_ for the list of resolved issues
+See the `PyMongo 4.12.1 release notes in JIRA`_ for the list of resolved issues
 in this release.
 
-.. _PyMongo 4.12 release notes in JIRA: https://jira.mongodb.org/secure/ReleaseNote.jspa?projectId=10004&version=41916
-.. _PYTHON-5288: https://jira.mongodb.org/browse/PYTHON-5288
+.. _PyMongo 4.12.1 release notes in JIRA: https://jira.mongodb.org/secure/ReleaseNote.jspa?projectId=10004&version=43094
 
 Changes in Version 4.12.0 (2025/04/08)
 --------------------------------------

pymongo/pool_shared.py

@@ -346,12 +346,10 @@ async def _configured_protocol_interface(
             ssl=ssl_context,
         )
     except _CertificateError:
-        transport.abort()
         # Raise _CertificateError directly like we do after match_hostname
         # below.
         raise
     except (OSError, SSLError) as exc:
-        transport.abort()
         # We raise AutoReconnect for transient and permanent SSL handshake
         # failures alike. Permanent handshake failures, like protocol
         # mismatch, will be turned into ServerSelectionTimeoutErrors later.