DEP: 0 should be passed to bincount, not None

Fixes gh-8841

2 files changed, 16 insertions, 2 deletions

diff --git a/numpy/core/src/multiarray/compiled_base.c b/numpy/core/src/multiarray/compiled_base.c
index 36ef1d1c4..f254022c9 100644
--- a/numpy/core/src/multiarray/compiled_base.c
+++ b/numpy/core/src/multiarray/compiled_base.c
@@ -96,7 +96,7 @@ minmax(const npy_intp *data, npy_intp data_len, npy_intp *mn, npy_intp *mx)
 NPY_NO_EXPORT PyObject *
 arr_bincount(PyObject *NPY_UNUSED(self), PyObject *args, PyObject *kwds)
 {
-    PyObject *list = NULL, *weight = Py_None, *mlength = Py_None;
+    PyObject *list = NULL, *weight = Py_None, *mlength = NULL;
     PyArrayObject *lst = NULL, *ans = NULL, *wts = NULL;
     npy_intp *numbers, *ians, len, mx, mn, ans_size, minlength;
     npy_intp i;
@@ -114,7 +114,15 @@ arr_bincount(PyObject *NPY_UNUSED(self), PyObject *args, PyObject *kwds)
     }
     len = PyArray_SIZE(lst);
 
-    if (mlength == Py_None) {
+    if (mlength == NULL) {
+        minlength = 0;
+    }
+    else if (mlength == Py_None) {
+        /* NumPy 1.14, 2017-06-01 */
+        if (DEPRECATE("0 should be passed as minlength instead of None; "
+                      "this will error in future.") < 0) {
+            goto fail;
+        }
         minlength = 0;
     }
     else {
diff --git a/numpy/core/tests/test_deprecations.py b/numpy/core/tests/test_deprecations.py
index d7c402b53..1c1851fc7 100644
--- a/numpy/core/tests/test_deprecations.py
+++ b/numpy/core/tests/test_deprecations.py
@@ -463,5 +463,11 @@ class TestTruthTestingEmptyArrays(_DeprecationTestCase):
         self.assert_deprecated(bool, args=(np.zeros((0, 0)),))
 
 
+class TestBincount(_DeprecationTestCase):
+    # 2017-06-01, 1.14.0
+    def test_bincount_minlength(self):
+        self.assert_deprecated(lambda: np.bincount([1, 2, 3], minlength=None))
+
+
 if __name__ == "__main__":
     run_module_suite()