Issues with concat and yao circuit

[sai-lalith]

Describe the bug
I am trying to perform operations on a concatenated matrix, and this throws bugs for me. My initial hunch after looking at the source code and debugging is that the concat method inherited from MultiArray is outputting a MultiArray rather than a matrix. Maybe I might be wrong; I am pretty new to MPC.

To Reproduce

Code ran:
`
b = Matrix(2, 2, sbit)
b.assign_all(0)
c = Matrix (2, 2, sbit)
c.assign_all(1)
b = b.concat (c)

@for_range(len(b))
def _(i):
print_ln('%s', b[i].reveal())
`

Error:

Expected behavior
The operations should just print as expected. I get the expected output if I comment out the concat part.

Also, this is the case only for yao and sbits. I tried testing with making everything sint and running with Mascot, and it worked well.

`
b = Matrix(2, 2, sint)
b.assign_all(0)
c = Matrix (2, 2, sint)
c.assign_all(1)
b = b.concat(c)

@for_range(len(b))
def _(i):
print_ln('%s', b[i].reveal())`

MP-SPDZ version
Latest

[mkskeller]

Thank you for raising this. You should find that 71631ce fixes it.

[sai-lalith]

Thanks very much for the fix, it works well.