From 7a4b162bf8189c27d736a3937be438365d20804a Mon Sep 17 00:00:00 2001
From: pavel-zotov <p519446@yandex.ru>
Date: Sat, 18 Jan 2025 15:02:29 +0300
Subject: [PATCH] Added/Updated tests\bugs\gh_8225_test.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/bugs/gh_8225_test.py | 37 ++++++++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/tests/bugs/gh_8225_test.py b/tests/bugs/gh_8225_test.py
index 47eeeab7..4388518a 100644
--- a/tests/bugs/gh_8225_test.py
+++ b/tests/bugs/gh_8225_test.py
@@ -10,13 +10,20 @@ NOTES:
     Parameter 'SubQueryConversion' currently presents only in FB 5.x and _NOT_ in FB 6.x.
     Because of that, testing version are limited only for 5.0.2. FB 6.x currently is NOT tested.
 
+    [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").
+    
     Confirmed bug on 5.0.2.1479-adfe97a.
     Checked on 5.0.2.1482-604555f.
 """
 
 import pytest
 from firebird.qa import *
-from firebird.driver import driver_config, connect
+from firebird.driver import driver_config, connect, DatabaseError
 
 init_script = """
     create domain dm_emp_id smallint;
@@ -91,10 +98,30 @@ def test_1(act: Action, capsys):
             for r in cur:
                 print(r[0],r[1])
 
-            ps = cur.prepare(test_sql)
-            print( '\n'.join([replace_leading(s) for s in ps.detailed_plan.split('\n')]) )
-            for r in cur.execute(ps):
-                print(r[0],r[1])
+            ps, rs = None, None
+            try:
+                ps = cur.prepare(test_sql)
+                print( '\n'.join([replace_leading(s) for s in ps.detailed_plan.split('\n')]) )
+
+                # ::: 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],r[1])
+
+            except DatabaseError as e:
+                print(e.__str__())
+                print(e.gds_codes)
+            finally:
+                if rs:
+                    rs.close() # <<< EXPLICITLY CLOSING CURSOR RESULTS
+                if ps:
+                    ps.free()
+
             con.rollback()
 
     act.expected_stdout = f"""