From eb99deb2ee2089a5582ea68260813255d7ef4982 Mon Sep 17 00:00:00 2001
From: pavel-zotov <p519446@yandex.ru>
Date: Sat, 18 Jan 2025 14:46:39 +0300
Subject: [PATCH] Added/Updated tests\functional\tabloid\test_aae2ae32.py:
 Resultset of cursor that executes using instance of selectable
 PreparedStatement must be stored in some variable in order to have ability
 close it EXPLICITLY, before PS will be freed. Otherwise access violation can
 raises when Python runs garbage collection.

---
 tests/functional/tabloid/test_aae2ae32.py | 24 +++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/tests/functional/tabloid/test_aae2ae32.py b/tests/functional/tabloid/test_aae2ae32.py
index 1fed532d..afde4a68 100644
--- a/tests/functional/tabloid/test_aae2ae32.py
+++ b/tests/functional/tabloid/test_aae2ae32.py
@@ -25,6 +25,13 @@ NOTES:
        Because of that, testing version are limited only for 5.0.2. FB 6.x currently is NOT tested.
     4. Custom driver config objects are created here, one with SubQueryConversion = true and second with false.
     
+    [18.01.2025] pzotov
+    Resultset of cursor that executes using instance of selectable PreparedStatement must be stored
+    in some variable in order to have ability close it EXPLICITLY (before PS will be freed).
+    Otherwise access violation raises during Python GC and pytest hangs at final point (does not return control to OS).
+    This occurs at least for: Python 3.11.2 / pytest: 7.4.4 / firebird.driver: 1.10.6 / Firebird.Qa: 0.19.3
+    The reason of that was explained by Vlad, 26.10.24 17:42 ("oddities when use instances of selective statements").
+
     Checked on 5.0.2.1516-92316F0 -- all ok: two hash joins instead of subquery.
     Thanks to dimitr for the advice on implementing the test.
 """
@@ -33,6 +40,7 @@ import pytest
 from firebird.qa import *
 from firebird.driver import driver_config, connect, DatabaseError
 
+
 init_script = """
     create table test1(id int not null);
     create table test2(id int not null, pid int not null);
@@ -90,6 +98,7 @@ def test_1(act: Action, capsys):
         """
 
         with connect(db_cfg_name, user = act.db.user, password = act.db.password) as con:
+            ps, rs = None, None
             try:
                 cur = con.cursor()
                 cur.execute("select g.rdb$config_name, g.rdb$config_value from rdb$database r left join rdb$config g on g.rdb$config_name = 'SubQueryConversion'")
@@ -101,12 +110,23 @@ def test_1(act: Action, capsys):
                 # Print explained plan with padding eash line by dots in order to see indentations:
                 print( '\n'.join([replace_leading(s) for s in ps.detailed_plan.split('\n')]) )
 
-                # Print data:
-                for r in cur.execute(ps):
+                # ::: NB ::: 'ps' returns data, i.e. this is SELECTABLE expression.
+                # We have to store result of cur.execute(<psInstance>) in order to
+                # close it explicitly.
+                # Otherwise AV can occur during Python garbage collection and this
+                # causes pytest to hang on its final point.
+                # Explained by hvlad, email 26.10.24 17:42
+                rs = cur.execute(ps)
+                for r in rs:
                     print(r[0])
             except DatabaseError as e:
                 print(e.__str__())
                 print(e.gds_codes)
+            finally:
+                if rs:
+                    rs.close() # <<< EXPLICITLY CLOSING CURSOR RESULTS
+                if ps:
+                    ps.free()
 
     act.expected_stdout = f"""
         SubQueryConversion true