add test for stable sort

1 files changed, 6 insertions, 0 deletions

diff --git a/numpy/ma/tests/test_core.py b/numpy/ma/tests/test_core.py
index 4c6bb2b42..ff1e087b5 100644
--- a/numpy/ma/tests/test_core.py
+++ b/numpy/ma/tests/test_core.py
@@ -3200,6 +3200,12 @@ class TestMaskedArrayMethods(object):
         assert_equal(sortedx._data, [1, 2, -2, -1, 0])
         assert_equal(sortedx._mask, [1, 1, 0, 0, 0])
 
+    def test_stable_sort(self):
+        x = array([1, 2, 3, 1, 2, 3], dtype=np.uint8)
+        expected = array([0, 3, 1, 4, 2, 5])
+        computed = argsort(x, kind='stable')
+        assert_equal(computed, expected)
+
     def test_argsort_matches_sort(self):
         x = array([1, 4, 2, 3], mask=[0, 1, 0, 0], dtype=np.uint8)