Fix the zero inner array case for Array::from(Vec)

Author: bluss

src/free_functions.rs

@@ -143,12 +143,16 @@ impl<A, V> From<Vec<V>> for Array2<A>
         let ptr = xs.as_mut_ptr();
         let len = xs.len();
         let cap = xs.capacity();
+        let expand_len = len * V::len();
         forget(xs);
         unsafe {
             let v = if size_of::<A>() == 0 {
-                Vec::from_raw_parts(ptr as *mut A, len * V::len(), cap)
+                Vec::from_raw_parts(ptr as *mut A, expand_len, expand_len)
+            } else if V::len() == 0 {
+                Vec::new()
             } else {
-                Vec::from_raw_parts(ptr as *mut A, len * V::len(), cap * V::len())
+                let expand_cap = cap * V::len();
+                Vec::from_raw_parts(ptr as *mut A, expand_len, expand_cap)
             };
             ArrayBase::from_shape_vec_unchecked(dim, v)
         }
@@ -164,14 +168,16 @@ impl<A, V, U> From<Vec<V>> for Array3<A>
         let ptr = xs.as_mut_ptr();
         let len = xs.len();
         let cap = xs.capacity();
+        let expand_len = len * V::len() * U::len();
         forget(xs);
         unsafe {
             let v = if size_of::<A>() == 0 {
-                Vec::from_raw_parts(ptr as *mut A, len * V::len(), cap)
+                Vec::from_raw_parts(ptr as *mut A, expand_len, expand_len)
+            } else if V::len() == 0 || U::len() == 0 {
+                Vec::new()
             } else {
-                let len = len * V::len() * U::len();
-                let cap = cap * V::len() * U::len();
-                Vec::from_raw_parts(ptr as *mut A, len, cap)
+                let expand_cap = cap * V::len() * U::len();
+                Vec::from_raw_parts(ptr as *mut A, expand_len, expand_cap)
             };
             ArrayBase::from_shape_vec_unchecked(dim, v)
         }

tests/array.rs

@@ -1112,3 +1112,11 @@ fn test_array_clone_same_view() {
     let b = a.clone();
     assert_eq!(a, b);
 }
+
+#[test]
+fn test_dimension_zero() {
+    let a: Array2<f32> = arr2(&[[], [], []]);
+    assert_eq!(vec![0.; 0], a.into_raw_vec());
+    let a: Array3<f32> = arr3(&[[[]], [[]], [[]]]);
+    assert_eq!(vec![0.; 0], a.into_raw_vec());
+}