[pkg-x2go-devel] Bug#766299: nxproxy: BIG-REQUESTS patch builds but fails at runtime

[paul.szabo at sydney.edu.au]

Dear Mike,

>> You have the new, patched nxproxy on both ends of the connection?
>> The encoding of the data has changed.
> ...
> nxagent and nxproxy are installed onto different systems from
> different sources ...
> So, this should be handled by your code then, I guess.

The encoding must change: some lengths must be sent; with BIG-REQUEST
they can be larger than 16 bits; and (for super-efficiency reasons?)
they were encoded into just 16 bits. I see no work-around other than
to change the encoding to 32 bits, as I did in my patch. Please let
me know if you can think of some other way.

The best that could be done is for nxproxy to detect the version used
on the other end, and refuse to talk if they did not match. Please let
me know if you think that would be worthwhile to pursue.

In the past, I see exactly similar, incompatible version changes, e.g.:
 - dxpc 3.9.0 being incompatible with earlier versions
   http://www.vigor.nu/dxpc/README
 - NX 3.5.0 issues with NoMachine 4
   https://www.nomachine.com/AR10I00603
I guess such is the price of progress, of having made the wrong design
choices (as seen in hindsight).

Cheers, Paul

Paul Szabo   psz at maths.usyd.edu.au   http://www.maths.usyd.edu.au/u/psz/
School of Mathematics and Statistics   University of Sydney    Australia