Re: a bug of read-passwd

[Chong Yidong]

> read_char needs to do arithmetic so it can recompute the remaining
> timeout, in case wait_reading_process_output returned an event
> which got discarded.  But this is not very hard.  Just add the
> specified timeout to the current time, at the start, and subtract
> the current time before each call to wait_reading_process_output.
>
> wait_reading_process_output does this same computation in order
> to call select with the proper remaining timeout.
>
> The inelegance of this is just a matter of repeating a little code.
> At the deeper level, this design is elegant because it is very safe.
> So I think we should try it.

I've checked in changes that implement this.  `read-event' and friends
now have an optional third argument that tells them how long to wait
for.