sympy/sympy — pull request #2598 by smichr (2013-11-15 03:06:55+00:00)
Title: preserve shape for 0-sized Matrices

make sure that `ones(0,1)+ones(0,1)` gives `Matrix(0, 1, [])` instead of `Matrix(0, 0, [])`

from https://code.google.com/p/sympy/issues/detail?id=4102