Merge remote-tracking branch 'origin/release-0.16'

Author: adamreichold

CHANGELOG.md

@@ -6,6 +6,7 @@
     - The destructive `PyArray::resize` method is now unsafe if used without an instance of `PyReadwriteArray`. ([#302](https://github.com/PyO3/rust-numpy/pull/302))
   - The `inner`, `dot` and `einsum` functions can also return a scalar instead of a zero-dimensional array to match NumPy's types ([#285](https://github.com/PyO3/rust-numpy/pull/285))
   - Deprecate `PyArray::from_exact_iter` after optimizing `PyArray::from_iter`. ([#292](https://github.com/PyO3/rust-numpy/pull/292))
+  - Fix returning invalid slices from `PyArray::{strides,shape}` for rank zero arrays. ([#303](https://github.com/PyO3/rust-numpy/pull/303))
 
 - v0.16.2
   - Fix build on platforms where `c_char` is `u8` like Linux/AArch64. ([#296](https://github.com/PyO3/rust-numpy/pull/296))

src/array.rs

@@ -302,6 +302,10 @@ impl<T, D> PyArray<T, D> {
     // C API: https://numpy.org/doc/stable/reference/c-api/array.html#c.PyArray_STRIDES
     pub fn strides(&self) -> &[isize] {
         let n = self.ndim();
+        if n == 0 {
+            cold();
+            return &[];
+        }
         let ptr = self.as_array_ptr();
         unsafe {
             let p = (*ptr).strides;
@@ -323,6 +327,10 @@ impl<T, D> PyArray<T, D> {
     // C API: https://numpy.org/doc/stable/reference/c-api/array.html#c.PyArray_DIMS
     pub fn shape(&self) -> &[usize] {
         let n = self.ndim();
+        if n == 0 {
+            cold();
+            return &[];
+        }
         let ptr = self.as_array_ptr();
         unsafe {
             let p = (*ptr).dimensions as *mut usize;

tests/array.rs

@@ -82,6 +82,17 @@ fn tuple_as_dim() {
     });
 }
 
+#[test]
+fn rank_zero_array_has_invalid_strides_dimensions() {
+    Python::with_gil(|py| {
+        let arr = PyArray::<f64, _>::zeros(py, (), false);
+
+        assert_eq!(arr.ndim(), 0);
+        assert_eq!(arr.strides(), &[]);
+        assert_eq!(arr.shape(), &[]);
+    })
+}
+
 #[test]
 fn zeros() {
     Python::with_gil(|py| {