DOC: add todo

Author: ngoldbaum

numpy/_core/src/multiarray/mapping.c

@@ -2092,7 +2092,8 @@ array_assign_subscript(PyArrayObject *self, PyObject *ind, PyObject *op)
         /* May need a generic copy function (only for refs and odd sizes) */
         NPY_ARRAYMETHOD_FLAGS transfer_flags;
         npy_intp itemsize = PyArray_ITEMSIZE(self);
-
+        // TODO: the heuristic used here to determine the src_dtype might be subtly wrong
+        // for non-REFCHK user DTypes. See gh-27057 for the prior discussion about this.
         if (PyArray_GetDTypeTransferFunction(
                 1, itemsize, itemsize,
                 allocated_array ? PyArray_DESCR(mit->extra_op) : PyArray_DESCR(self),