From 3470ce0430268f847a7e4d027e5f69956dee8742 Mon Sep 17 00:00:00 2001 From: "Erlend E. Aasland" Date: Thu, 18 Feb 2021 22:17:00 +0100 Subject: [PATCH 1/3] Prevent needless memory allocations of SQLite aggregate context --- Modules/_sqlite/connection.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c index 63fcb0055de2c9..d46af1a5eede37 100644 --- a/Modules/_sqlite/connection.c +++ b/Modules/_sqlite/connection.c @@ -708,7 +708,7 @@ void _pysqlite_final_callback(sqlite3_context* context) threadstate = PyGILState_Ensure(); - aggregate_instance = (PyObject**)sqlite3_aggregate_context(context, sizeof(PyObject*)); + aggregate_instance = (PyObject**)sqlite3_aggregate_context(context, 0); if (!*aggregate_instance) { /* this branch is executed if there was an exception in the aggregate's * __init__ */ From b7dd8c226a54ad93993396e3718fa9368e0fdc21 Mon Sep 17 00:00:00 2001 From: "Erlend E. Aasland" Date: Thu, 18 Feb 2021 22:33:49 +0100 Subject: [PATCH 2/3] Handle aggregate queries with no hits --- Lib/sqlite3/test/userfunctions.py | 5 +++++ Modules/_sqlite/connection.c | 6 +++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/Lib/sqlite3/test/userfunctions.py b/Lib/sqlite3/test/userfunctions.py index 2285abd4fd8a57..749ea049c834a8 100644 --- a/Lib/sqlite3/test/userfunctions.py +++ b/Lib/sqlite3/test/userfunctions.py @@ -429,6 +429,11 @@ def test_aggr_check_aggr_sum(self): val = cur.fetchone()[0] self.assertEqual(val, 60) + def test_aggr_no_match(self): + cur = self.con.execute("select mysum(i) from (select 1 as i) where i == 0") + val = cur.fetchone()[0] + self.assertIsNone(val) + class AuthorizerTests(unittest.TestCase): @staticmethod def authorizer_cb(action, arg1, arg2, dbname, source): diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c index d46af1a5eede37..39b55fc60da422 100644 --- a/Modules/_sqlite/connection.c +++ b/Modules/_sqlite/connection.c @@ -709,7 +709,11 @@ void _pysqlite_final_callback(sqlite3_context* context) threadstate = PyGILState_Ensure(); aggregate_instance = (PyObject**)sqlite3_aggregate_context(context, 0); - if (!*aggregate_instance) { + if (aggregate_instance == NULL) { + /* No rows matched the query; the step handler was never called. */ + goto error; + } + else if (!*aggregate_instance) { /* this branch is executed if there was an exception in the aggregate's * __init__ */ From 9722ea952a117ad25a39eb29c927f90bd34cde75 Mon Sep 17 00:00:00 2001 From: "Erlend E. Aasland" Date: Thu, 18 Feb 2021 23:31:03 +0100 Subject: [PATCH 3/3] Add NEWS --- .../next/Library/2021-02-18-23-30-52.bpo-43258.LeU-q8.rst | 2 ++ 1 file changed, 2 insertions(+) create mode 100644 Misc/NEWS.d/next/Library/2021-02-18-23-30-52.bpo-43258.LeU-q8.rst diff --git a/Misc/NEWS.d/next/Library/2021-02-18-23-30-52.bpo-43258.LeU-q8.rst b/Misc/NEWS.d/next/Library/2021-02-18-23-30-52.bpo-43258.LeU-q8.rst new file mode 100644 index 00000000000000..0529214718c445 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-02-18-23-30-52.bpo-43258.LeU-q8.rst @@ -0,0 +1,2 @@ +Prevent needless allocation of :mod:`sqlite3` aggregate function context +when no rows match an aggregate query. Patch by Erlend E. Aasland. pFad - Phonifier reborn

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