small visual glitch

[leapfog]

precondition:

$ PROMPT_COMMAND='stty echo'          <-- that's needed to trigger
$ source <(hstr -B)

• now invoke hstr via ctrl-r and interrupt it with ctrl-c
• until next ctrl-c or enter, all characters are echoed twice

That PROMPT_COMMAND is used to clean up after programs that fail re-enable echo, for example when they were interrupted while asking for a password.