[3.9] bpo-43853: Handle sqlite3_value_text() errors (GH-25422). (GH-27627)

(cherry picked from commit 006fd86)

Author: Erlend Egeberg Aasland

Lib/sqlite3/test/userfunctions.py

@@ -236,9 +236,11 @@ def CheckFuncException(self):
 
  def CheckParamString(self):
  cur = self.con.cursor()
- cur.execute("select isstring(?)", ("foo",))
- val = cur.fetchone()[0]
- self.assertEqual(val, 1)
+ for text in ["foo", str()]:
+ with self.subTest(text=text):
+ cur.execute("select isstring(?)", (text,))
+ val = cur.fetchone()[0]
+ self.assertEqual(val, 1)
 
  def CheckParamInt(self):
  cur = self.con.cursor()
@@ -387,9 +389,9 @@ def CheckAggrExceptionInFinalize(self):
 
  def CheckAggrCheckParamStr(self):
  cur = self.con.cursor()
- cur.execute("select checkType('str', ?)", ("foo",))
+ cur.execute("select checkTypes('str', ?, ?)", ("foo", str()))
  val = cur.fetchone()[0]
- self.assertEqual(val, 1)
+ self.assertEqual(val, 2)
 
  def CheckAggrCheckParamInt(self):
  cur = self.con.cursor()

Misc/NEWS.d/next/Library/2021-04-15-12-02-17.bpo-43853.XXCVAp.rst

@@ -0,0 +1,3 @@
+Improve :mod:`sqlite3` error handling: ``sqlite3_value_text()`` errors that
+set ``SQLITE_NOMEM`` now raise :exc:`MemoryError`. Patch by Erlend E.
+Aasland.

Modules/_sqlite/connection.c

@@ -546,7 +546,6 @@ PyObject* _pysqlite_build_py_params(sqlite3_context *context, int argc, sqlite3_
  int i;
  sqlite3_value* cur_value;
  PyObject* cur_py_value;
- const char* val_str;
  Py_ssize_t buflen;
 
  args = PyTuple_New(argc);
@@ -563,16 +562,19 @@ PyObject* _pysqlite_build_py_params(sqlite3_context *context, int argc, sqlite3_
  case SQLITE_FLOAT:
  cur_py_value = PyFloat_FromDouble(sqlite3_value_double(cur_value));
  break;
- case SQLITE_TEXT:
- val_str = (const char*)sqlite3_value_text(cur_value);
- cur_py_value = PyUnicode_FromString(val_str);
- /* TODO: have a way to show errors here */
- if (!cur_py_value) {
- PyErr_Clear();
- Py_INCREF(Py_None);
- cur_py_value = Py_None;
+ case SQLITE_TEXT: {
+ sqlite3 *db = sqlite3_context_db_handle(context);
+ const char *text = (const char *)sqlite3_value_text(cur_value);
+
+ if (text == NULL && sqlite3_errcode(db) == SQLITE_NOMEM) {
+ PyErr_NoMemory();
+ goto error;
  }
+
+ Py_ssize_t size = sqlite3_value_bytes(cur_value);
+ cur_py_value = PyUnicode_FromStringAndSize(text, size);
  break;
+ }
  case SQLITE_BLOB:
  buflen = sqlite3_value_bytes(cur_value);
  cur_py_value = PyBytes_FromStringAndSize(
@@ -585,15 +587,18 @@ PyObject* _pysqlite_build_py_params(sqlite3_context *context, int argc, sqlite3_
  }
 
  if (!cur_py_value) {
- Py_DECREF(args);
- return NULL;
+ goto error;
  }
 
  PyTuple_SetItem(args, i, cur_py_value);
 
  }
 
  return args;
+
+error:
+ Py_DECREF(args);
+ return NULL;
 }
 
 void _pysqlite_func_callback(sqlite3_context* context, int argc, sqlite3_value** argv)