Added/Updated tests\bugs\gh_8231_test.py: Checked on 5.0.2.1485-274af35 -- all ok.

tests/bugs/gh_8231_test.py

@@ -0,0 +1,98 @@
+#coding:utf-8
+
+"""
+ID:          issue-8231
+ISSUE:       https://github.com/FirebirdSQL/firebird/issues/8231
+TITLE:       SubQueryConversion = true --request size limit exceeded / Unsuccessful execution caused by an unavailable resource. unable to allocate memory from operating system
+DESCRIPTION:
+NOTES:
+    [26.08.2024] pzotov
+    Two tables must be joined by columns which has different charset or collates.
+    Confirmed bug on 5.0.2.1484-3cdfd38 (25.08.2024), got:
+        Statement failed, SQLSTATE = HY000
+        request size limit exceeded
+    Checked on 5.0.2.1485-274af35 -- all ok.
+
+    Thanks to dimitr for the advice on implementing the test.
+"""
+
+import pytest
+from firebird.qa import *
+from firebird.driver import driver_config, connect
+
+init_script = """
+    create table t1(fld varchar(10) character set win1252);
+    create table t2(fld varchar(10) character set utf8);
+
+    insert into t1(fld) values('Ð');
+    insert into t2(fld) values('Ð');
+    commit;
+"""
+
+db = db_factory(init=init_script)
+
+act = python_act('db')
+
+#-----------------------------------------------------------
+
+def replace_leading(source, char="."):
+    stripped = source.lstrip()
+    return char * (len(source) - len(stripped)) + stripped
+
+#-----------------------------------------------------------
+
+@pytest.mark.version('>=5.0.2,<6')
+def test_1(act: Action, capsys):
+
+    test_sql = """
+        select 1 as x
+        from t1
+        where exists (select 1 from t2 where t1.fld = t2.fld)
+    """
+
+    for sq_conv in ('true','false',):
+        srv_cfg = driver_config.register_server(name = f'srv_cfg_8231_{sq_conv}', config = '')
+        db_cfg_name = f'db_cfg_8231_{sq_conv}'
+        db_cfg_object = driver_config.register_database(name = db_cfg_name)
+        db_cfg_object.server.value = srv_cfg.name
+        db_cfg_object.database.value = str(act.db.db_path)
+        db_cfg_object.config.value = f"""
+            SubQueryConversion = {sq_conv}
+        """
+
+        with connect(db_cfg_name, user = act.db.user, password = act.db.password) as con:
+            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'")
+            for r in cur:
+                print(r[0],r[1])
+
+            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 data:
+            for r in cur.execute(ps):
+                print(r[0])
+            con.rollback()
+
+    act.expected_stdout = f"""
+        SubQueryConversion true
+        Select Expression
+        ....-> Nested Loop Join (semi)
+        ........-> Table "T1" Full Scan
+        ........-> Filter
+        ............-> Table "T2" Full Scan
+        1
+
+        SubQueryConversion false
+        Sub-query
+        ....-> Filter
+        ........-> Table "T2" Full Scan
+        Select Expression
+        ....-> Filter
+        ........-> Table "T1" Full Scan
+        1
+    """
+    act.stdout = capsys.readouterr().out
+    assert act.clean_stdout == act.clean_expected_stdout