Readline uses the characters \001 and \002 to mark the start and end
of zero-length character sequnces in the prompt before prompt
expansion. Without these characters the input point can become offset
from the visual end of the prompt when performing some actions.
The display refresh is automatically enabled or disabled depending on
the width of the window. This allows to avoid the incorrect display on
refresh for the small windows.
Instead of calling display(""), explicitly use the sequence of
commands to force readline to properly update its internal state
and re-display the prompt.
Keep cursor's position consistent when passphrase is reaching
its maximum by adding characters in the middle of the string
The use case is very rare as not many people will attempt to
modify the masked passphrase from the middle.
Previously, CTRL+D used to cause termination of the client. Now, the
command will cancel the agent’s prompts in agent mod. In regular mode
the behavior is unchanged.
Due to the changed IO behavior, pasting of the secrets
into the agent prompt became impossible. The reimplemented
logic allows to add (paste) an arbitrary number of characters
into a desired position of a secret string up to its max lengths.
The deletion has also been reworked to accommodate the new behavior.
Entering 23 characters at a prompt resulted in 9 extra characters being
added to the line. At this point, you would only be abel to backspace
until the 9th character.
It seems that claling both rl_replace_line("", 0) and rl_redisplay()
before rl_replace_line(masked_input.mask, 0) causes this to happen. Both
calls are redundant anyways as iwctl functions exactly the same without
them (plus no more bug).
We'd add the new command propmpt to history if it was different from
what current_history() returned which may not be the last command
executed, so we'd possibly add multiple identical commands to history
and skip some that were new. Instead compare against
history_get(last index).
Also remove an always-true part of the condition on the next line.
