Sudden death by X_ShmAttach when running over ssh

[martinwguy]

I'm developing a new program on GNU/Linux using SDL2 for graphics, but when I run it over ssh -X the program suddenly dies on startup with exit status 1 saying:

X Error of failed request:  BadRequest (invalid request code or no such operation)
  Major opcode of failed request:  130 (MIT-SHM)
  Minor opcode of failed request:  1 (X_ShmAttach)
  Serial number of failed request:  214
  Current serial number in output stream:  215

It turns out that it's dying inside SDL_GetWindowSurface() the first time that is called, and exiting with status 1, rather than returning a failure code and letting the program fail more gracefully. At present my program does pixel access by getting the surface's memory and poking into it inside a SDL_Lock/UnlockSurface() pair. I assume that's impossible when the display and program are on different machines and was hoping to use a different SDL primitive in that scenario, although the EFL port of the same program works fine in those conditions. Either way, it would be nicer if SDL_GetWindowSurface() were to fail rather than bombing out.