Re: backward-kill-word is not refreshing correctly

[Chet Ramey]

Jay Freeman (saurik) wrote:
>>> When I type a long string of text and start pressing ctrl-W to 
>>> backwards-kill words, bash deletes the words but doesn't visually refresh 
>>> (the words still appear on the command line). This was not occurring for me 
>>> in the 3.x series of Bash.
> 
>> I having a problem similar to this. For me, kill-word /never/
>> refreshes the screen. Additionally, moving up/down through the command
>> history doesn't always cause a refresh either (in a manner
>> deterministic but stochastic).
> ...
>> I have tried building bash 4.x against ncurses 5.4 and 5.7, I have
>> tried compiling it against a standalone readline 6.x and using a built-
>> in copy, and I have tried compiling both for thumb and arm.
> 
> And, it turns out that had I tested a standalone readline 5.2, it
> would have worked fine ;P. The problem was introduced somewhere in
> readline between bash 3.2 and 4.0. I figured this out by playing with
> bash some to figure out where it was displaying things to the screen,
> and then started whittling away at the diff of readline's display.c
> from 3.2 to 4.0.
> 
> In the end I managed to isolate it down to the single diff hunk that
> was causing the problem. It should be made clear that I have no clue
> what this code is doing, or why it was changed from 3.2 to 4.0: all I
> know is that the old version worked for me, and this one did not. I am
> therefore not advocating that removing it is the "correct" fix, and am
> only providing this information in the hope it will help debug the
> issue.

I can't reproduce the problem, and it seems to only appear in builds
for your iphone.  I'm going to need help with it. :-)

Please check the values of _rl_last_c_pos and _rl_screenwidth when this
code is executed and the problem occurs.  It's likely that the former is
set incorrectly somewhere, but I can't tell that for sure yet.

Chet

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer

Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/