Added/Updated tests\bugs\core_1315_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/core_1315_test.py

@@ -6,9 +6,17 @@ ISSUE:       1734
 TITLE:       Data type unknown
 DESCRIPTION:
 JIRA:        CORE-1315
-FBTEST:      bugs.core_1315
+NOTES:
+    [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").
 """
 
+from firebird.driver import DatabaseError
+
 import pytest
 from firebird.qa import *
 
@@ -16,7 +24,8 @@ db = db_factory()
 
 act = python_act('db')
 
-expected_stdout = """COALESCE
+expected_stdout = """
+    COALESCE
     -----------
     2
 
@@ -28,14 +37,32 @@ COALESCE
 @pytest.mark.version('>=3')
 def test_1(act: Action, capsys):
     with act.db.connect() as con:
-        c = con.cursor()
-        statement = c.prepare('select coalesce(?,1) from RDB$DATABASE')
-        c.execute(statement,[2])
-        act.print_data(c)
-        c.execute(statement,[None])
-        act.print_data(c)
+        cur = con.cursor()
+        ps, rs = None, None
+        try:
+            ps = cur.prepare('select coalesce(?,1) from RDB$DATABASE')
+
+            # ::: 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,[2])
+            act.print_data(rs)
+
+            rs = cur.execute(ps,[None])
+            act.print_data(rs)
+
+        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.stdout = capsys.readouterr().out
         act.expected_stdout = expected_stdout
         assert act.clean_stdout == act.clean_expected_stdout
-
-