bpo-31770: Prevent a crash and refleaks when calling sqlite3.Cursor.__init__() more than once (GH-3968) (#4301)

(cherry picked from commit e56ab746a965277ffcc4396d8a0902b6e072d049)

1 files changed, 7 insertions, 8 deletions

diff --git a/Modules/_sqlite/cursor.c b/Modules/_sqlite/cursor.c
index 8341fb8..b6257a0 100644
--- a/Modules/_sqlite/cursor.c
+++ b/Modules/_sqlite/cursor.c
@@ -39,21 +39,20 @@ static int pysqlite_cursor_init(pysqlite_Cursor* self, PyObject* args, PyObject*
     }
 
     Py_INCREF(connection);
-    self->connection = connection;
-    self->statement = NULL;
-    self->next_row = NULL;
-    self->in_weakreflist = NULL;
+    Py_XSETREF(self->connection, connection);
+    Py_CLEAR(self->statement);
+    Py_CLEAR(self->next_row);
 
-    self->row_cast_map = PyList_New(0);
+    Py_XSETREF(self->row_cast_map, PyList_New(0));
     if (!self->row_cast_map) {
         return -1;
     }
 
     Py_INCREF(Py_None);
-    self->description = Py_None;
+    Py_XSETREF(self->description, Py_None);
 
     Py_INCREF(Py_None);
-    self->lastrowid= Py_None;
+    Py_XSETREF(self->lastrowid, Py_None);
 
     self->arraysize = 1;
     self->closed = 0;
@@ -62,7 +61,7 @@ static int pysqlite_cursor_init(pysqlite_Cursor* self, PyObject* args, PyObject*
     self->rowcount = -1L;
 
     Py_INCREF(Py_None);
-    self->row_factory = Py_None;
+    Py_XSETREF(self->row_factory, Py_None);
 
     if (!pysqlite_check_thread(self->connection)) {
         return -1;