The cursor is weakly referenceable

NEWS-2.3

@@ -6,7 +6,7 @@ What's new in psycopg 2.3.3
   - Added `register_composite()` function to cast PostgreSQL composite types
     into Python tuples/namedtuples.
   - The build script refuses to guess values if pg_config is not found.
-  - Connections are weakly referenceable.
+  - Connections and cursors are weakly referenceable.
 
 * Bug fixes:
 

psycopg/cursor.h

@@ -81,6 +81,8 @@ typedef struct {
     PyObject *string_types;   /* a set of typecasters for string types */
     PyObject *binary_types;   /* a set of typecasters for binary types */
 
+    PyObject *weakreflist;    /* list of weak references */
+
 } cursorObject;
 
 /* C-callable functions in cursor_int.c and cursor_ext.c */

psycopg/cursor_type.c

@@ -1642,6 +1642,7 @@ cursor_setup(cursorObject *self, connectionObject *conn, const char *name)
 
     self->string_types = NULL;
     self->binary_types = NULL;
+    self->weakreflist = NULL;
 
     Py_INCREF(Py_None);
     self->description = Py_None;
@@ -1668,6 +1669,10 @@ cursor_dealloc(PyObject* obj)
 {
     cursorObject *self = (cursorObject *)obj;
 
+    if (self->weakreflist) {
+        PyObject_ClearWeakRefs(obj);
+    }
+
     PyObject_GC_UnTrack(self);
 
     if (self->name) PyMem_Free(self->name);
@@ -1769,14 +1774,15 @@ PyTypeObject cursorType = {
     0,          /*tp_as_buffer*/
 
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_ITER |
-      Py_TPFLAGS_HAVE_GC, /*tp_flags*/
+      Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_HAVE_WEAKREFS ,
+                /*tp_flags*/
     cursorType_doc, /*tp_doc*/
 
     (traverseproc)cursor_traverse, /*tp_traverse*/
     0,          /*tp_clear*/
 
     0,          /*tp_richcompare*/
-    0,          /*tp_weaklistoffset*/
+    offsetof(cursorObject, weakreflist), /*tp_weaklistoffset*/
 
     cursor_iter, /*tp_iter*/
     cursor_next, /*tp_iternext*/

tests/test_cursor.py

@@ -99,6 +99,13 @@ class CursorTests(unittest.TestCase):
         curs2 = self.conn.cursor()
         self.assertEqual("foofoo", curs2.cast(705, 'foo'))
 
+    def test_weakref(self):
+        from weakref import ref
+        curs = self.conn.cursor()
+        w = ref(curs)
+        del curs
+        self.assert_(w() is None)
+
 
 def test_suite():
     return unittest.TestLoader().loadTestsFromName(__name__)