[3.10] gh-108342: Break ref cycle in SSLSocket._create() exc (GH-108344) (#108350)

Explicitly break a reference cycle when SSLSocket._create() raises an
exception. Clear the variable storing the exception, since the
exception traceback contains the variables and so creates a reference
cycle.

This test leak was introduced by the test added for the fix of GH-108310.
(cherry picked from commit 64f99350351bc46e016b2286f36ba7cd669b79e3)

Co-authored-by: Victor Stinner <vstinner@python.org>

diff --git a/Lib/ssl.py b/Lib/ssl.py
index fadbee217afd526e10d557a86137d7d51e5dba2d..f386fa7831528f3e595d7920a88548f66765d7a1 100644 (file)
--- a/Lib/ssl.py
+++ b/Lib/ssl.py
@@ -1079,7 +1079,11 @@ class SSLSocket(socket):
                     self.close()
                 except OSError:
                     pass
-                raise notconn_pre_handshake_data_error
+                try:
+                    raise notconn_pre_handshake_data_error
+                finally:
+                    # Explicitly break the reference cycle.
+                    notconn_pre_handshake_data_error = None
         else:
             connected = True