bpo-40744: Drop support for SQLite pre 3.7.3 (GH-20909)

Remove code required to support SQLite pre 3.7.3. Co-written-by: Berker Peksag <berker.peksag@gmail.com> Co-written-by: Sergey Fedoseev <fedoseev.sergey@gmail.com>

Author: Erlend Egeberg Aasland

Doc/library/sqlite3.rst

@@ -18,7 +18,8 @@ application using SQLite and then port the code to a larger database such as
 PostgreSQL or Oracle.
 
 The sqlite3 module was written by Gerhard Häring. It provides a SQL interface
-compliant with the DB-API 2.0 specification described by :pep:`249`.
+compliant with the DB-API 2.0 specification described by :pep:`249`, and
+requires SQLite 3.7.3 or newer.
 
 To use the module, you must first create a :class:`Connection` object that
 represents the database. Here the data will be stored in the
@@ -591,8 +592,6 @@ Connection Objects
  dest = sqlite3.connect(':memory:')
  source.backup(dest)
 
- Availability: SQLite 3.6.11 or higher
-
  .. versionadded:: 3.7
 
 
@@ -701,9 +700,6 @@ Cursor Objects
  statements because we cannot determine the number of rows a query produced
  until all rows were fetched.
 
- With SQLite versions before 3.6.5, :attr:`rowcount` is set to 0 if
- you make a ``DELETE FROM table`` without any condition.
-
  .. attribute:: lastrowid
 
  This read-only attribute provides the rowid of the last modified row. It is

Doc/whatsnew/3.10.rst

@@ -191,10 +191,15 @@ that may require changes to your code.
 Build Changes
 =============
 
+
 * The C99 functions :c:func:`snprintf` and :c:func:`vsnprintf` are now required
  to build Python.
  (Contributed by Victor Stinner in :issue:`36020`.)
 
+* :mod:`sqlite3` requires SQLite 3.7.3 or higher.
+ (Contributed by Sergey Fedoseev and Erlend E. Aasland :issue:`40744`.)
+
+
 
 C API Changes
 =============

Lib/sqlite3/test/backup.py

@@ -2,7 +2,6 @@
 import unittest
 
 
-@unittest.skipIf(sqlite.sqlite_version_info < (3, 6, 11), "Backup API not supported")
 class BackupTests(unittest.TestCase):
  def setUp(self):
  cx = self.cx = sqlite.connect(":memory:")

Lib/sqlite3/test/dbapi.py

@@ -185,12 +185,6 @@ def CheckOpenUri(self):
  with self.assertRaises(sqlite.OperationalError):
  cx.execute('insert into test(id) values(1)')
 
- @unittest.skipIf(sqlite.sqlite_version_info >= (3, 3, 1),
- 'needs sqlite versions older than 3.3.1')
- def CheckSameThreadErrorOnOldVersion(self):
- with self.assertRaises(sqlite.NotSupportedError) as cm:
- sqlite.connect(':memory:', check_same_thread=False)
- self.assertEqual(str(cm.exception), 'shared connections not available')
 
 class CursorTests(unittest.TestCase):
  def setUp(self):

Lib/sqlite3/test/hooks.py

@@ -61,8 +61,6 @@ def upper(self):
  self.assertEqual(result[0][0], 'b')
  self.assertEqual(result[1][0], 'a')
 
- @unittest.skipIf(sqlite.sqlite_version_info < (3, 2, 1),
- 'old SQLite versions crash on this test')
  def CheckCollationIsUsed(self):
  def mycoll(x, y):
  # reverse order
@@ -240,16 +238,12 @@ def trace(statement):
  traced_statements.append(statement)
  con.set_trace_callback(trace)
  con.execute("create table foo(x)")
- # Can't execute bound parameters as their values don't appear
- # in traced statements before SQLite 3.6.21
- # (cf. http://www.sqlite.org/draft/releaselog/3_6_21.html)
  con.execute('insert into foo(x) values ("%s")' % unicode_value)
  con.commit()
  self.assertTrue(any(unicode_value in stmt for stmt in traced_statements),
  "Unicode data %s garbled in trace callback: %s"
  % (ascii(unicode_value), ', '.join(map(ascii, traced_statements))))
 
- @unittest.skipIf(sqlite.sqlite_version_info < (3, 3, 9), "sqlite3_prepare_v2 is not available")
  def CheckTraceCallbackContent(self):
  # set_trace_callback() shouldn't produce duplicate content (bpo-26187)
  traced_statements = []

Lib/sqlite3/test/regression.py

@@ -87,7 +87,6 @@ def CheckStatementFinalizationOnCloseDb(self):
  cur.execute("select 1 x union select " + str(i))
  con.close()
 
- @unittest.skipIf(sqlite.sqlite_version_info < (3, 2, 2), 'needs sqlite 3.2.2 or newer')
  def CheckOnConflictRollback(self):
  con = sqlite.connect(":memory:")
  con.execute("create table foo(x, unique(x) on conflict rollback)")

Lib/sqlite3/test/transactions.py

@@ -111,16 +111,12 @@ def CheckToggleAutoCommit(self):
  res = self.cur2.fetchall()
  self.assertEqual(len(res), 1)
 
- @unittest.skipIf(sqlite.sqlite_version_info < (3, 2, 2),
- 'test hangs on sqlite versions older than 3.2.2')
  def CheckRaiseTimeout(self):
  self.cur1.execute("create table test(i)")
  self.cur1.execute("insert into test(i) values (5)")
  with self.assertRaises(sqlite.OperationalError):
  self.cur2.execute("insert into test(i) values (5)")
 
- @unittest.skipIf(sqlite.sqlite_version_info < (3, 2, 2),
- 'test hangs on sqlite versions older than 3.2.2')
  def CheckLocking(self):
  """
  This tests the improved concurrency with pysqlite 2.3.4. You needed

Lib/sqlite3/test/types.py

@@ -401,8 +401,6 @@ def CheckSqliteTimestamp(self):
  ts2 = self.cur.fetchone()[0]
  self.assertEqual(ts, ts2)
 
- @unittest.skipIf(sqlite.sqlite_version_info < (3, 1),
- 'the date functions are available on 3.1 or later')
  def CheckSqlTimestamp(self):
  now = datetime.datetime.utcnow()
  self.cur.execute("insert into test(ts) values (current_timestamp)")

Misc/NEWS.d/next/Library/2020-05-30-08-10-23.bpo-40744.jKURVV.rst

@@ -0,0 +1,4 @@
+The :mod:`sqlite3` module uses SQLite API functions that require SQLite
+v3.7.3 or higher. This patch removes support for older SQLite versions, and
+explicitly requires SQLite 3.7.3 both at build, compile and runtime. Patch by
+Sergey Fedoseev and Erlend E. Aasland.

Modules/_sqlite/connection.c

@@ -33,16 +33,6 @@
 #define ACTION_FINALIZE 1
 #define ACTION_RESET 2
 
-#if SQLITE_VERSION_NUMBER >= 3003008
-#ifndef SQLITE_OMIT_LOAD_EXTENSION
-#define HAVE_LOAD_EXTENSION
-#endif
-#endif
-
-#if SQLITE_VERSION_NUMBER >= 3006011
-#define HAVE_BACKUP_API
-#endif
-
 #if SQLITE_VERSION_NUMBER >= 3014000
 #define HAVE_TRACE_V2
 #endif
@@ -61,18 +51,6 @@ static int pysqlite_connection_set_isolation_level(pysqlite_Connection* self, Py
 static void _pysqlite_drop_unused_cursor_references(pysqlite_Connection* self);
 
 
-static void _sqlite3_result_error(sqlite3_context* ctx, const char* errmsg, int len)
-{
- /* in older SQLite versions, calling sqlite3_result_error in callbacks
- * triggers a bug in SQLite that leads either to irritating results or
- * segfaults, depending on the SQLite version */
-#if SQLITE_VERSION_NUMBER >= 3003003
- sqlite3_result_error(ctx, errmsg, len);
-#else
- PyErr_SetString(pysqlite_OperationalError, errmsg);
-#endif
-}
-
 int pysqlite_connection_init(pysqlite_Connection* self, PyObject* args, PyObject* kwargs)
 {
  static char *kwlist[] = {
@@ -182,10 +160,6 @@ int pysqlite_connection_init(pysqlite_Connection* self, PyObject* args, PyObject
  self->timeout = timeout;
  (void)sqlite3_busy_timeout(self->db, (int)(timeout*1000));
  self->thread_ident = PyThread_get_thread_ident();
- if (!check_same_thread && sqlite3_libversion_number() < 3003001) {
- PyErr_SetString(pysqlite_NotSupportedError, "shared connections not available");
- return -1;
- }
  self->check_same_thread = check_same_thread;
 
  self->function_pinboard_trace_callback = NULL;
@@ -620,7 +594,7 @@ void _pysqlite_func_callback(sqlite3_context* context, int argc, sqlite3_value**
  } else {
  PyErr_Clear();
  }
- _sqlite3_result_error(context, "user-defined function raised exception", -1);
+ sqlite3_result_error(context, "user-defined function raised exception", -1);
  }
 
  PyGILState_Release(threadstate);
@@ -652,7 +626,7 @@ static void _pysqlite_step_callback(sqlite3_context *context, int argc, sqlite3_
  } else {
  PyErr_Clear();
  }
- _sqlite3_result_error(context, "user-defined aggregate's '__init__' method raised error", -1);
+ sqlite3_result_error(context, "user-defined aggregate's '__init__' method raised error", -1);
  goto error;
  }
  }
@@ -676,7 +650,7 @@ static void _pysqlite_step_callback(sqlite3_context *context, int argc, sqlite3_
  } else {
  PyErr_Clear();
  }
- _sqlite3_result_error(context, "user-defined aggregate's 'step' method raised error", -1);
+ sqlite3_result_error(context, "user-defined aggregate's 'step' method raised error", -1);
  }
 
 error:
@@ -693,7 +667,6 @@ void _pysqlite_final_callback(sqlite3_context* context)
  _Py_IDENTIFIER(finalize);
  int ok;
  PyObject *exception, *value, *tb;
- int restore;
 
  PyGILState_STATE threadstate;
 
@@ -709,7 +682,6 @@ void _pysqlite_final_callback(sqlite3_context* context)
 
  /* Keep the exception (if any) of the last call to step() */
  PyErr_Fetch(&exception, &value, &tb);
- restore = 1;
 
  function_result = _PyObject_CallMethodIdNoArgs(*aggregate_instance, &PyId_finalize);
 
@@ -726,19 +698,12 @@ void _pysqlite_final_callback(sqlite3_context* context)
  } else {
  PyErr_Clear();
  }
- _sqlite3_result_error(context, "user-defined aggregate's 'finalize' method raised error", -1);
-#if SQLITE_VERSION_NUMBER < 3003003
- /* with old SQLite versions, _sqlite3_result_error() sets a new Python
- exception, so don't restore the previous exception */
- restore = 0;
-#endif
+ sqlite3_result_error(context, "user-defined aggregate's 'finalize' method raised error", -1);
  }
 
- if (restore) {
- /* Restore the exception (if any) of the last call to step(),
- but clear also the current exception if finalize() failed */
- PyErr_Restore(exception, value, tb);
- }
+ /* Restore the exception (if any) of the last call to step(),
+ but clear also the current exception if finalize() failed */
+ PyErr_Restore(exception, value, tb);
 
 error:
  PyGILState_Release(threadstate);
@@ -1110,7 +1075,7 @@ static PyObject* pysqlite_connection_set_trace_callback(pysqlite_Connection* sel
  Py_RETURN_NONE;
 }
 
-#ifdef HAVE_LOAD_EXTENSION
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
 static PyObject* pysqlite_enable_load_extension(pysqlite_Connection* self, PyObject* args)
 {
  int rc;
@@ -1513,7 +1478,6 @@ pysqlite_connection_iterdump(pysqlite_Connection* self, PyObject* args)
  return retval;
 }
 
-#ifdef HAVE_BACKUP_API
 static PyObject *
 pysqlite_connection_backup(pysqlite_Connection *self, PyObject *args, PyObject *kwds)
 {
@@ -1664,7 +1628,6 @@ pysqlite_connection_backup(pysqlite_Connection *self, PyObject *args, PyObject *
  return NULL;
  }
 }
-#endif
 
 static PyObject *
 pysqlite_connection_create_collation(pysqlite_Connection* self, PyObject* args)
@@ -1816,7 +1779,7 @@ static PyMethodDef connection_methods[] = {
  PyDoc_STR("Creates a new aggregate. Non-standard.")},
  {"set_authorizer", (PyCFunction)(void(*)(void))pysqlite_connection_set_authorizer, METH_VARARGS|METH_KEYWORDS,
  PyDoc_STR("Sets authorizer callback. Non-standard.")},
- #ifdef HAVE_LOAD_EXTENSION
+ #ifndef SQLITE_OMIT_LOAD_EXTENSION
  {"enable_load_extension", (PyCFunction)pysqlite_enable_load_extension, METH_VARARGS,
  PyDoc_STR("Enable dynamic loading of SQLite extension modules. Non-standard.")},
  {"load_extension", (PyCFunction)pysqlite_load_extension, METH_VARARGS,
@@ -1838,10 +1801,8 @@ static PyMethodDef connection_methods[] = {
  PyDoc_STR("Abort any pending database operation. Non-standard.")},
  {"iterdump", (PyCFunction)pysqlite_connection_iterdump, METH_NOARGS,
  PyDoc_STR("Returns iterator to the dump of the database in an SQL text format. Non-standard.")},
- #ifdef HAVE_BACKUP_API
  {"backup", (PyCFunction)(void(*)(void))pysqlite_connection_backup, METH_VARARGS | METH_KEYWORDS,
  PyDoc_STR("Makes a backup of the database. Non-standard.")},
- #endif
  {"__enter__", (PyCFunction)pysqlite_connection_enter, METH_NOARGS,
  PyDoc_STR("For context manager. Non-standard.")},
  {"__exit__", (PyCFunction)pysqlite_connection_exit, METH_VARARGS,