BUG: Fix auxdata initialization in ufunc slow path

seberg · seberg · commit 834bf310aea6 · 2025-01-07T11:52:51.000+01:00
The reason this was not found earlier is that auxdata is currently set by most function and the fast path seems to be taken a shocking amount of times. There are no further similar missing inits. Closes gh-28117
diff --git a/numpy/_core/src/umath/ufunc_object.c b/numpy/_core/src/umath/ufunc_object.c
@@ -1108,7 +1108,7 @@ execute_ufunc_loop(PyArrayMethod_Context *context, int masked,
      * based on the fixed strides.
      */
     PyArrayMethod_StridedLoop *strided_loop;
-    NpyAuxData *auxdata;
+    NpyAuxData *auxdata = NULL;
     npy_intp fixed_strides[NPY_MAXARGS];
 
     NpyIter_GetInnerFixedStrideArray(iter, fixed_strides);
diff --git a/numpy/_core/tests/test_nep50_promotions.py b/numpy/_core/tests/test_nep50_promotions.py
@@ -237,6 +237,20 @@ def test_integer_comparison(sctype, other_val, comp):
     assert_array_equal(comp(other_val, val_obj), comp(other_val, val))
 
 
+@pytest.mark.parametrize("arr", [
+    np.ones((100, 100), dtype=np.uint8)[::2],  # not trivially iterable
+    np.ones(20000, dtype=">u4"),  # cast and >buffersize
+    np.ones(100, dtype=">u4"),  # fast path compatible with cast
+])
+def test_integer_comparison_with_cast(arr):
+    # Similar to above, but mainly test a few cases that cover the slow path
+    # the test is limited to unsigned ints and -1 for simplicity.
+    res = arr >= -1
+    assert_array_equal(res, np.ones_like(arr, dtype=bool))
+    res = arr < -1
+    assert_array_equal(res, np.zeros_like(arr, dtype=bool))
+
+
 @pytest.mark.parametrize("comp",
         [np.equal, np.not_equal, np.less_equal, np.less,
          np.greater_equal, np.greater])
