[bug][player] Race-y input polling: Can/can't RMB-scroll during framestep-back

[Simon]

NL 12.04

This seems hard to reproduce, and I speculate that it's a race condition in NL's keyboard/mouse input polling.

• Have a machine that endures a framerate drop during continuously held framestep-back. I repro this on my laptop (can't test on desktop today): 2018 laptop, Intel integrated graphics chip, Arch Linux, NL runs in Wine 4.0-rc3.
  
• Map hold-to-scroll to RMB (right mouse button) and framestep-back-by-1-frame to 2 (the number 2 = the key above W).
  
• Play a large level, e.g., Minim level-solving contest 1.
  
• Zoom into the level far enough such that the game allows you to scroll around the map, i.e., do not have all of the map visible at the same time.
  
• Fast-forward to maybe 5 minutes in the level. No need to assign anything.
  
• Press and hold 2 (the number key) to framestep-back continuously. Never let go of the key until you're done reproducing this bug.
  
• Press RMB (right mose button) and hold it for about a second, move the mosue frantically while holding as if you were scrolling with hold-to-scroll. Repeat this step several times.
  

Expected: Every press-and-hold of RMB in the last step allowed you to scroll via the hold-to-scroll function.

Observed instead: Only some of the press-and-holds allowed you to scroll.

-- Simon

[Nepster]

Thanks for the bug report, but this feels like a low-priority and high-effort bug to me. So for the moment, this goes on the stack of stuff to do, whenever I have nothing more productive to do and need a challange.