Scroll Lock not working as expected

[Jonas Nicolaisen]

   Hello,

   I'm running bash 5.0.17(1)-release under Ubuntu 20.04 in a virtual
   terminal.

   The "Scroll Lock" key is not working as expected. It will halt the
   scrolling output from a command like dmesg or find, but it will not
   enable scrolling through the backbuffer with the cursor keys, although
   that is what the key is originally for. It was supposed to let you use
   the arrow keys to scroll through the backbuffer if you don't have a
   wheel mouse.

   Expected behaviour during Scroll Lock:

   1) Scrolling output is halted

   2) Arrow keys will move the entire screen across the content of the
   console buffer (like Shift+PgUp does in Linux terminals).

   Why is this better than Shift+PgUp? Because it is easier to use, and
   there is an actual hardware key for it that's going unused. It's just
   weird that the key doesn't work.

   Is there any chance that this could be fixed to work as expected at
   least in a TTY (X is a different story...)? I noticed that Scroll Lock
   does nothing in X-based terminals either (not even the LED lights up),
   but in a VTY at least it works halfway. Could it be fixed to work all
   the way?

   PS. I noticed that INSERT doesn't do anything in bash either. The
   expected behaviour would be that after pressing INSERT, typing any
   characters would overwrite whatever is to the right of them. Any chance
   that this gets fixed as well?

   I'm asking on this mailing list because I reckon it's possible that
   Bash developers don't want to include this functionality for some
   reason, so it might not be a bug, but intended behaviour. Is that the
   case?

   I don't see any harm in fixing this.

   Kind regards

   Jonas Nicolaisen