Merge pull request #2893 from mwiebe/reduceat_empty

Reduceat regression fix

1 files changed, 15 insertions, 0 deletions

diff --git a/numpy/core/tests/test_umath.py b/numpy/core/tests/test_umath.py
index c2304a748..b2d47d052 100644
--- a/numpy/core/tests/test_umath.py
+++ b/numpy/core/tests/test_umath.py
@@ -1263,6 +1263,21 @@ def test_reduceat():
     np.setbufsize(np.UFUNC_BUFSIZE_DEFAULT)
     assert_array_almost_equal(h1, h2)
 
+def test_reduceat_empty():
+    """Reduceat should work with empty arrays"""
+    indices = np.array([], 'i4')
+    x = np.array([], 'f8')
+    result = np.add.reduceat(x, indices)
+    assert_equal(result.dtype, x.dtype)
+    assert_equal(result.shape, (0,))
+    # Another case with a slightly different zero-sized shape
+    x = np.ones((5,2))
+    result = np.add.reduceat(x, [], axis=0)
+    assert_equal(result.dtype, x.dtype)
+    assert_equal(result.shape, (0, 2))
+    result = np.add.reduceat(x, [], axis=1)
+    assert_equal(result.dtype, x.dtype)
+    assert_equal(result.shape, (5, 0))
 
 def test_complex_nan_comparisons():
     nans = [complex(np.nan, 0), complex(0, np.nan), complex(np.nan, np.nan)]