BUG: 'bool' object has no attribute 'ndim'

[charris]

Backport of #17907.

I get the following error in the tifffile tests while comparing large bilevel images using numpy's assert_array_equal function. It looks like a typo.

x = array([[ True,  True,  True, ...,  True,  True,  True],
       [ True,  True,  True, ...,  True,  True,  True],
      ...True],
       [ True,  True,  True, ...,  True,  True,  True],
       [ True,  True,  True, ...,  True,  True,  True]])
y = array([[ True,  True,  True, ...,  True,  True,  True],
       [ True,  True,  True, ...,  True,  True,  True],
      ...True],
       [ True,  True,  True, ...,  True,  True,  True],
       [ True,  True,  True, ...,  True,  True,  True]])
func = <function assert_array_compare.<locals>.<lambda> at 0x0B085810>, hasval = '+inf'

    def func_assert_same_pos(x, y, func=isnan, hasval='nan'):
        """Handling nan/inf.

        Combine results of running func on x and y, checking that they are True
        at the same locations.

        """
        x_id = func(x)
        y_id = func(y)
        # We include work-arounds here to handle three types of slightly
        # pathological ndarray subclasses:
        # (1) all() on `masked` array scalars can return masked arrays, so we
        #     use != True
        # (2) __eq__ on some ndarray subclasses returns Python booleans
        #     instead of element-wise comparisons, so we cast to bool_() and
        #     use isinstance(..., bool) checks
        # (3) subclasses with bare-bones __array_function__ implementations may
        #     not implement np.all(), so favor using the .all() method
        # We are not committed to supporting such subclasses, but it's nice to
        # support them if possible.
        if bool_(x_id == y_id).all() != True:
            msg = build_err_msg([x, y],
                                err_msg + '\nx and y %s location mismatch:'
                                % (hasval), verbose=verbose, header=header,
                                names=('x', 'y'), precision=precision)
            raise AssertionError(msg)
        # If there is a scalar, then here we know the array has the same
        # flag as it everywhere, so we should return the scalar flag.
        if isinstance(x_id, bool) or x_id.ndim == 0:
            return bool_(x_id)
>       elif isinstance(x_id, bool) or y_id.ndim == 0:
E       AttributeError: 'bool' object has no attribute 'ndim'