[issue40784] test_sqlite: CheckFuncDeterministic() fails with SQLite 3.32

[STINNER Victor]

New submission from STINNER Victor <vstinner at python.org>:

With SQLite 3.32, test_sqlite fails with:

FAIL: CheckFuncDeterministic (sqlite3.test.userfunctions.FunctionTests)
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Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.9.0b1/Lib/sqlite3/test/userfunctions.py", line 290, in CheckFuncDeterministic
    self.assertEqual(mock.call_count, 1)
AssertionError: 2 != 1

This test defines a "deterministic" function and ensures that calling it twice in SQLite with only call the underyling Python function only once.

Copy of the test:

    @unittest.skipIf(sqlite.sqlite_version_info < (3, 8, 3), "deterministic parameter not supported")
    def CheckFuncDeterministic(self):
        mock = unittest.mock.Mock(return_value=None)
        self.con.create_function("deterministic", 0, mock, deterministic=True)
        self.con.execute("select deterministic() = deterministic()")
        self.assertEqual(mock.call_count, 1)

In pysqlite_connection_create_function() of Modules/_sqlite/connection.c, determistic=1 sets the following flag:

        flags |= SQLITE_DETERMINISTIC;

This flag is documented as:
"A deterministic function always gives the same answer when it has the same inputs."

* https://www.sqlite.org/deterministic.html
* https://www.sqlite.org/c3ref/c_deterministic.html

"SELECT 1 WHERE deterministic() = deterministic()" query also calls the mock twice.

Running "SELECT deterministic()" query twice also calls the mock twice.

It seems like SQLite 3.32 behaves differently.

Fedora issue: https://bugzilla.redhat.com/show_bug.cgi?id=1839826

----------
components: Tests
messages: 370022
nosy: ghaering, vstinner
priority: normal
severity: normal
status: open
title: test_sqlite: CheckFuncDeterministic() fails with SQLite 3.32
versions: Python 3.10

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<https://bugs.python.org/issue40784>
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