BUG: random: Check 'writeable' flag in 'shuffle' and 'permuted'.

2 files changed, 19 insertions, 0 deletions

diff --git a/numpy/random/tests/test_generator_mt19937.py b/numpy/random/tests/test_generator_mt19937.py
index e5411b8ef..e16a82973 100644
--- a/numpy/random/tests/test_generator_mt19937.py
+++ b/numpy/random/tests/test_generator_mt19937.py
@@ -1020,6 +1020,13 @@ class TestRandomDist:
         arr = np.ones((3, 2))
         assert_raises(np.AxisError, random.shuffle, arr, 2)
 
+    def test_shuffle_not_writeable(self):
+        random = Generator(MT19937(self.seed))
+        a = np.zeros(5)
+        a.flags.writeable = False
+        with pytest.raises(ValueError, match='read-only'):
+            random.shuffle(a)
+
     def test_permutation(self):
         random = Generator(MT19937(self.seed))
         alist = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
@@ -1116,6 +1123,12 @@ class TestRandomDist:
         with pytest.raises(TypeError, match='Cannot cast'):
             random.permuted(x, axis=1, out=out)
 
+    def test_permuted_not_writeable(self):
+        x = np.zeros((2, 5))
+        x.flags.writeable = False
+        with pytest.raises(ValueError, match='read-only'):
+            random.permuted(x, axis=1, out=x)
+
     def test_beta(self):
         random = Generator(MT19937(self.seed))
         actual = random.beta(.1, .9, size=(3, 2))
diff --git a/numpy/random/tests/test_random.py b/numpy/random/tests/test_random.py
index 6a584a511..773b63653 100644
--- a/numpy/random/tests/test_random.py
+++ b/numpy/random/tests/test_random.py
@@ -564,6 +564,12 @@ class TestRandomDist:
         rng.shuffle(a)
         assert_equal(np.asarray(a), [4, 1, 0, 3, 2])
 
+    def test_shuffle_not_writeable(self):
+        a = np.zeros(3)
+        a.flags.writeable = False
+        with pytest.raises(ValueError, match='read-only'):
+            np.random.shuffle(a)
+
     def test_beta(self):
         np.random.seed(self.seed)
         actual = np.random.beta(.1, .9, size=(3, 2))