Merge pull request #27809 from seberg/issue-27777

charris · web-flow · commit b85a149fea2c · 2024-11-21T09:50:27.000-07:00
BUG: Fix array flags propagation in boolean indexing
diff --git a/numpy/_core/src/multiarray/mapping.c b/numpy/_core/src/multiarray/mapping.c
@@ -1058,7 +1058,7 @@ array_boolean_subscript(PyArrayObject *self,
         ret = (PyArrayObject *)PyArray_NewFromDescrAndBase(
                 Py_TYPE(self), ret_dtype,
                 1, &size, PyArray_STRIDES(ret), PyArray_BYTES(ret),
-                PyArray_FLAGS(self), (PyObject *)self, (PyObject *)tmp);
+                PyArray_FLAGS(ret), (PyObject *)self, (PyObject *)tmp);
 
         Py_DECREF(tmp);
         if (ret == NULL) {
diff --git a/numpy/_core/tests/test_indexing.py b/numpy/_core/tests/test_indexing.py
@@ -409,15 +409,19 @@ def test_array_like_values(self):
         a[...] = memoryview(s)
         assert_array_equal(a, s)
 
-    def test_subclass_writeable(self):
+    @pytest.mark.parametrize("writeable", [True, False])
+    def test_subclass_writeable(self, writeable):
         d = np.rec.array([('NGC1001', 11), ('NGC1002', 1.), ('NGC1003', 1.)],
                          dtype=[('target', 'S20'), ('V_mag', '>f4')])
+        d.flags.writeable = writeable
+        # Advanced indexing results are always writeable:
         ind = np.array([False,  True,  True], dtype=bool)
-        assert_(d[ind].flags.writeable)
+        assert d[ind].flags.writeable
         ind = np.array([0, 1])
-        assert_(d[ind].flags.writeable)
-        assert_(d[...].flags.writeable)
-        assert_(d[0].flags.writeable)
+        assert d[ind].flags.writeable
+        # Views should be writeable if the original array is:
+        assert d[...].flags.writeable == writeable
+        assert d[0].flags.writeable == writeable
 
     def test_memory_order(self):
         # This is not necessary to preserve. Memory layouts for
