Bsxfun with empty input

Hello,
I think I have found bug/different behavior in bsxfun():
a = pi;
a(1) = [];
bsxfun(@plus, a, ones(4,1))
...returns...
ans =
Empty matrix: 4-by-0

but

a = mp('pi');
a(1) = [];
bsxfun(@plus, a, ones(4,1))
...returns...
Error using mp/subsref (line 990)
Index exceeds matrix dimensions.

Error in mpbsxfun (line 71)

Error in mp/bsxfun (line 1132)
[varargout{1:nargout}] = mpbsxfun(varargin{:});

I am running:
MATLAB Version: 8.5.0.197613 (R2015a)

Multiprecision Computing Toolbox, (c) 2008-2017 Advanpix LLC.
Version : 4.3.2 Build 12170
Platform: Win64
Release : 2017-01-16

Trial version. Valid until 2017-01-30

Best regards,
Vladimir