From 6f0c3feaf088e78c75f2abee90164f20446eba08 Mon Sep 17 00:00:00 2001
From: Wenzel Jakob <wenzel.jakob@epfl.ch>
Date: Wed, 14 Jun 2023 15:48:18 +0200
Subject: [PATCH] incorporate feedback by @WKarel

---
 docs/ndarray.rst           | 3 ++-
 include/nanobind/ndarray.h | 5 +++++
 src/nb_ndarray.cpp         | 9 ++-------
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/docs/ndarray.rst b/docs/ndarray.rst
index 2c56df0e..e9468e75 100644
--- a/docs/ndarray.rst
+++ b/docs/ndarray.rst
@@ -353,7 +353,8 @@ interpreted as follows:
   ndarray's ``owner`` field to a method's ``self`` argument. It fails with an
   error if there is already a different owner.
 
-- :cpp:enumerator:`rv_policy::move` is unsupported.
+- :cpp:enumerator:`rv_policy::move` is unsupported and demoted to
+  :cpp:enumerator:`rv_policy::copy`.
 
 Limitations
 -----------
diff --git a/include/nanobind/ndarray.h b/include/nanobind/ndarray.h
index 014e040b..674fa2dc 100644
--- a/include/nanobind/ndarray.h
+++ b/include/nanobind/ndarray.h
@@ -298,10 +298,15 @@ template <typename... Args> class ndarray {
             dlpack::dtype dtype = nanobind::dtype<Scalar>(),
             int32_t device_type = device::cpu::value,
             int32_t device_id = 0) {
+
+        if (strides.size() != 0 && strides.size() != shape.size())
+            detail::fail("ndarray(): shape and strides have incompatible size!");
+
         m_handle = detail::ndarray_create(
             (void *) value, shape.size(), shape.begin(), owner.ptr(),
             (strides.size() == 0) ? nullptr : strides.begin(), &dtype,
             std::is_const_v<Scalar>, device_type, device_id);
+
         m_dltensor = *detail::ndarray_inc_ref(m_handle);
     }
 
diff --git a/src/nb_ndarray.cpp b/src/nb_ndarray.cpp
index f0e78e8f..9e36c68a 100644
--- a/src/nb_ndarray.cpp
+++ b/src/nb_ndarray.cpp
@@ -614,7 +614,7 @@ PyObject *ndarray_wrap(ndarray_handle *th, int framework,
     bool copy;
     switch (policy) {
         case rv_policy::reference_internal:
-            if (cleanup->self() != th->owner) {
+            if (cleanup && cleanup->self() != th->owner) {
                 if (th->owner) {
                     PyErr_SetString(PyExc_RuntimeError,
                                     "nanobind::detail::ndarray_wrap(): "
@@ -633,15 +633,10 @@ PyObject *ndarray_wrap(ndarray_handle *th, int framework,
             break;
 
         case rv_policy::copy:
+        case rv_policy::move:
             copy = true;
             break;
 
-        case rv_policy::move:
-            PyErr_SetString(PyExc_RuntimeError,
-                            "nanobind::detail::ndarray_wrap(): rv_policy::move "
-                            "is not supported!");
-            return nullptr;
-
         default:
             copy = false;
             break;