From 1301cd17ffac9666edfb94425aadd3864ba57257 Mon Sep 17 00:00:00 2001
From: pavel-zotov <p519446@yandex.ru>
Date: Sat, 18 Jan 2025 15:07:04 +0300
Subject: [PATCH] Added/Updated tests\bugs\gh_8231_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_8231_test.py | 38 +++++++++++++++++++++++++++++++-------
 1 file changed, 31 insertions(+), 7 deletions(-)

diff --git a/tests/bugs/gh_8231_test.py b/tests/bugs/gh_8231_test.py
index 3ac420cc..a91a43aa 100644
--- a/tests/bugs/gh_8231_test.py
+++ b/tests/bugs/gh_8231_test.py
@@ -13,12 +13,19 @@ NOTES:
         request size limit exceeded
     Checked on 5.0.2.1485-274af35 -- all ok.
 
+    [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").
+    
     Thanks to dimitr for the advice on implementing the test.
 """
 
 import pytest
 from firebird.qa import *
-from firebird.driver import driver_config, connect
+from firebird.driver import driver_config, connect, DatabaseError
 
 init_script = """
     create table t1(fld varchar(10) character set win1252);
@@ -66,14 +73,31 @@ def test_1(act: Action, capsys):
             for r in cur:
                 print(r[0],r[1])
 
-            ps = cur.prepare(test_sql)
+            ps, rs = None, None
+            try:
+                ps = cur.prepare(test_sql)
 
-            # 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 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')]) )
+
+                # ::: 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:
+                print(e.__str__())
+                print(e.gds_codes)
+            finally:
+                if rs:
+                    rs.close() # <<< EXPLICITLY CLOSING CURSOR RESULTS
+                if ps:
+                    ps.free()
 
-            # Print data:
-            for r in cur.execute(ps):
-                print(r[0])
             con.rollback()
 
     act.expected_stdout = f"""