Maximum namelength for variables in -v6 .mat files

[Rik]

3/13/13

All,

I'm trying to resolve a report (https://savannah.gnu.org/bugs/?34676) where
Octave is truncating variables saved in -v6 format to 31 characters. 
Octave is definitely doing this.  I find this line in the code

  size_t max_namelen = (mat7_format ? 63 : 31);

But what does Matlab itself do?  Could someone with Matlab verify the
following?

clear all;
x12345678901234567890123456789012345 = 1;
save ('tst.mat', '-v6');
clear all;
load ('tst.mat');
who

--Rik