python
diff --git a/‎Lib/sqlite3/test/regression.py
Lines changed: 18 additions & 0 deletions b/‎Lib/sqlite3/test/regression.py
Lines changed: 18 additions & 0 deletions
diff --git a/‎Misc/NEWS.d/next/Library/2017-10-12-18-45-38.bpo-31770.GV3MPx.rst
Lines changed: 2 additions & 0 deletions b/‎Misc/NEWS.d/next/Library/2017-10-12-18-45-38.bpo-31770.GV3MPx.rst
Lines changed: 2 additions & 0 deletions
diff --git a/‎Modules/_sqlite/cursor.c
Lines changed: 7 additions & 8 deletions b/‎Modules/_sqlite/cursor.c
Lines changed: 7 additions & 8 deletions
@@ -24,6 +24,8 @@
 import datetime
 import unittest
 import sqlite3 as sqlite
+import weakref
+from test import support
 
 class RegressionTests(unittest.TestCase):
     def setUp(self):
@@ -358,6 +360,22 @@ def CheckCommitCursorReset(self):
             counter += 1
         self.assertEqual(counter, 3, "should have returned exactly three rows")
 
+    def CheckBpo31770(self):
+        """
+        The interpreter shouldn't crash in case Cursor.__init__() is called
+        more than once.
+        """
+        def callback(*args):
+            pass
+        con = sqlite.connect(":memory:")
+        cur = sqlite.Cursor(con)
+        ref = weakref.ref(cur, callback)
+        cur.__init__(con)
+        del cur
+        # The interpreter shouldn't crash when ref is collected.
+        del ref
+        support.gc_collect()
+
 
 def suite():
     regression_suite = unittest.makeSuite(RegressionTests, "Check")
 
@@ -0,0 +1,2 @@
+Prevent a crash when calling the ``__init__()`` method of a
+``sqlite3.Cursor`` object more than once. Patch by Oren Milman.
@@ -78,21 +78,20 @@ static int pysqlite_cursor_init(pysqlite_Cursor* self, PyObject* args, PyObject*
     }
 
     Py_INCREF(connection);
-    self->connection = connection;
-    self->statement = NULL;
-    <
E096
span class=pl-s1>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;
@@ -101,7 +100,7 @@ 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;
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+Prevent a crash when calling the ``__init__()`` method of a
	`2`	+``sqlite3.Cursor`` object more than once. Patch by Oren Milman.