BUG: don't use PyArray_Converter in may_share_memory

The converter function has NPY_ARRAY_CARRAY enabled, which can cause
false negatives for non-ndarray inputs.

Fixes gh-5604

1 files changed, 28 insertions, 0 deletions

diff --git a/numpy/core/tests/test_mem_overlap.py b/numpy/core/tests/test_mem_overlap.py
index 728cc675d..8d39fa4c0 100644
--- a/numpy/core/tests/test_mem_overlap.py
+++ b/numpy/core/tests/test_mem_overlap.py
@@ -482,5 +482,33 @@ def test_internal_overlap_fuzz():
             no_overlap += 1
 
 
+def test_non_ndarray_inputs():
+    # Regression check for gh-5604
+
+    class MyArray(object):
+        def __init__(self, data):
+            self.data = data
+
+        @property
+        def __array_interface__(self):
+            return self.data.__array_interface__
+
+    class MyArray2(object):
+        def __init__(self, data):
+            self.data = data
+
+        def __array__(self):
+            return self.data
+
+    for cls in [MyArray, MyArray2]:
+        x = np.arange(5)
+
+        assert_(np.may_share_memory(cls(x[::2]), x[1::2]))
+        assert_(not np.shares_memory(cls(x[::2]), x[1::2]))
+
+        assert_(np.shares_memory(cls(x[1::3]), x[::2]))
+        assert_(np.may_share_memory(cls(x[1::3]), x[::2]))
+
+
 if __name__ == "__main__":
     run_module_suite()