Added/Updated tests\bugs\gh_8115_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_8115_test.py

@@ -14,6 +14,13 @@ NOTES:
         https://github.com/FirebirdSQL/firebird/commit/bbd35ab07c129e9735f081fcd29172a8187aa8ab
         Avoid reading/hashing the inner stream(s) if the leader stream is empty
 
+    [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 6.0.0.457, 5.0.2.1499
 """
 import zipfile
@@ -57,17 +64,29 @@ def test_1(act: Action, tmp_fbk: Path, capsys):
 
     with act.db.connect() as con:
         cur = con.cursor()
-        ps = cur.prepare(test_sql)
+        ps, rs = None, None
-        print( '\n'.join([replace_leading(s) for s in ps.detailed_plan.split('\n')]) )
-
         try:
-            cur.execute(ps)
+            ps = cur.prepare(test_sql)
-            for r in cur:
+            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:
                 for p in r:
                     print(p)
         except DatabaseError as e:
             print(e.__str__())
             print(e.gds_codes)
+        finally:
+            if rs:
+                rs.close() # <<< EXPLICITLY CLOSING CURSOR RESULTS
+            if ps:
+                ps.free()
 
     expected_stdout_5x = """
         Select Expression