BUG: Remove logical object ufuncs with bool output

While this makes sense, the implementation here does not actually
work.  It is very difficult to actually reach it, but if reached
it just crashes the process, so remove it.

(I am not actually sure why the input needs to be object already
here, that seems to be an issue with the current dispatcher/promotion
special casing object a bit oddly.)

2 files changed, 22 insertions, 3 deletions

diff --git a/numpy/core/code_generators/generate_umath.py b/numpy/core/code_generators/generate_umath.py
index 1b6917ebc..4891e8f23 100644
--- a/numpy/core/code_generators/generate_umath.py
+++ b/numpy/core/code_generators/generate_umath.py
@@ -489,7 +489,6 @@ defdict = {
           'PyUFunc_SimpleBinaryComparisonTypeResolver',
           TD(nodatetime_or_obj, out='?', simd=[('avx2', ints)]),
           TD(O, f='npy_ObjectLogicalAnd'),
-          TD(O, f='npy_ObjectLogicalAnd', out='?'),
           ),
 'logical_not':
     Ufunc(1, 1, None,
@@ -497,7 +496,6 @@ defdict = {
           None,
           TD(nodatetime_or_obj, out='?', simd=[('avx2', ints)]),
           TD(O, f='npy_ObjectLogicalNot'),
-          TD(O, f='npy_ObjectLogicalNot', out='?'),
           ),
 'logical_or':
     Ufunc(2, 1, False_,
@@ -505,13 +503,13 @@ defdict = {
           'PyUFunc_SimpleBinaryComparisonTypeResolver',
           TD(nodatetime_or_obj, out='?', simd=[('avx2', ints)]),
           TD(O, f='npy_ObjectLogicalOr'),
-          TD(O, f='npy_ObjectLogicalOr', out='?'),
           ),
 'logical_xor':
     Ufunc(2, 1, False_,
           docstrings.get('numpy.core.umath.logical_xor'),
           'PyUFunc_SimpleBinaryComparisonTypeResolver',
           TD(nodatetime_or_obj, out='?'),
+          # TODO: using obj.logical_xor() seems pretty much useless:
           TD(P, f='logical_xor'),
           ),
 'maximum':
diff --git a/numpy/core/tests/test_ufunc.py b/numpy/core/tests/test_ufunc.py
index dab11d948..877319c0c 100644
--- a/numpy/core/tests/test_ufunc.py
+++ b/numpy/core/tests/test_ufunc.py
@@ -2049,6 +2049,27 @@ class TestUfunc:
             assert_raises(TypeError, f, a, b)
             assert_raises(TypeError, f, c, a)
 
+    @pytest.mark.parametrize("ufunc",
+             [np.logical_and, np.logical_or])  # logical_xor object loop is bad
+    @pytest.mark.parametrize("signature",
+             [(None, None, object), (object, None, None),
+              (None, object, None)])
+    def test_logical_ufuncs_object_signatures(self, ufunc, signature):
+        a = np.array([True, None, False], dtype=object)
+        res = ufunc(a, a, signature=signature)
+        assert res.dtype == object
+
+    @pytest.mark.parametrize("ufunc",
+            [np.logical_and, np.logical_or, np.logical_xor])
+    @pytest.mark.parametrize("signature",
+                 [(bool, None, object), (object, None, bool),
+                  (None, object, bool)])
+    def test_logical_ufuncs_mixed_object_signatures(self, ufunc, signature):
+        # Most mixed signatures fail (except those with bool out, e.g. `OO->?`)
+        a = np.array([True, None, False])
+        with pytest.raises(TypeError):
+            ufunc(a, a, signature=signature)
+
     def test_reduce_noncontig_output(self):
         # Check that reduction deals with non-contiguous output arrays
         # appropriately.