Add unit test showing regression in stacked neighborhood iterator.

If a first neigh iterator n1 is created to that the neighborhood is
strictly inside and smaller than the array, the second iterator on top
of it will wrongly use n1 boundaries outside the neighborhood, even if
still within the array.

1 files changed, 10 insertions, 0 deletions

diff --git a/numpy/core/tests/test_multiarray.py b/numpy/core/tests/test_multiarray.py
index a45012771..133a67f3c 100644
--- a/numpy/core/tests/test_multiarray.py
+++ b/numpy/core/tests/test_multiarray.py
@@ -1354,5 +1354,15 @@ class TestStackedNeighborhoodIter(TestCase):
                 [-2, 2], NEIGH_MODE['circular'])
         assert_array_equal(l, r)
 
+    # 4th simple, 1d test: stacking 2 neigh iterators, but with lower iterator
+    # being strictly within the array
+    def test_simple_strict_within(self):
+        dt = np.float64
+        # Stacking zero on top of mirror
+        x = np.array([1, 2, 3], dtype=dt)
+        r = [np.array([1, 2, 3], dtype=dt)]
+        l = test_neighborhood_iterator_oob(x, [1, 1], NEIGH_MODE['zero'],
+                [-1, 1], NEIGH_MODE['zero'])
+        assert_array_equal(l, r)
 if __name__ == "__main__":
     run_module_suite()