ZLE redraw bug

ZLE redraw bug

[Matt Wozniski]

OK, this has been bugging me for a while, and was still an issue with
4.3.5 dev 4, so I finally sat down to try to get a manageable test
case for it.  Hopefully this is small enough.  :)

zsh -f
mastermind% autoload -U compinit; compinit
mastermind% zstyle ':completion:*' completer _approximate
mastermind% zstyle ':completion:*' menu select=2
mastermind% path=()
mastermind% function manpath { }
mastermind% mna<TAB> ("mna" changes to "enable" from menu selection)
enable     mailpath   manpath    manpath    nameddirs  _nautilus  unalias
mna

note that manpath appears twice in the listing - I think that's what's
screwing things up internally...  because if I now do <CTRL-u> to kill
the line, I get:

<-snip->
mastermind% enable
enable     m

mna
<-snap>

with the cursor after the 'm' on the second line.

If I then do "unfunction manpath" and try the completion/line kill
again, things work properly.

Can anyone help me figure out what might be going wrong?  I don't even
know where to begin debugging ZLE, heh.

Thanks!
~Matt

Re: ZLE redraw bug

[Peter Stephenson]

On Thu, 27 Mar 2008 03:47:50 -0400
"Matt Wozniski" <godlygeek@gmail.com> wrote:
> OK, this has been bugging me for a while, and was still an issue with
> 4.3.5 dev 4, so I finally sat down to try to get a manageable test
> case for it.  Hopefully this is small enough.  :)

Thanks for removing my excuse for not looking at it.  You must know how
much I enjoy complist.c.  (If anyone doesn't, I would be delighted to
refresh their memory.)

As always I don't really understand very much around here, but the point
at which it's going wrong is when it's refreshing the screen to clear up
the list.  It seems that it needs a bit of prodding in the right
direction to realise that it should be reinitialising the list rather
than using what it last printed.  I think.

I'll commit this because I do *not* want to think any more about it;
everyone is encouraged to give the menu selection code a good work out.

Index: Src/Zle/complist.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Zle/complist.c,v
retrieving revision 1.108
diff -u -r1.108 complist.c
--- Src/Zle/complist.c	28 Feb 2008 23:12:37 -0000	1.108
+++ Src/Zle/complist.c	28 Mar 2008 23:14:08 -0000
@@ -53,7 +53,7 @@
  * selected: Used to signal between domenucomplete() and menuselect()
  *           that a selected entry has been found.  Or something.
  * mlbeg:    The first line of the logical array of all matches that
- *           fits on screen.
+ *           fits on screen.  Setting this to -1 forces a redraw.
  * mlend:    The line after the last that fits on screen.
  * mscroll:  1 if the scrolling prompt is shown on screen.
  * mrestlines: The number of screen lines remaining to be processed.
@@ -3216,6 +3216,15 @@
 	}
     }
     if (!noselect && (!dat || acc)) {
+	/*
+	 * I added the following because in certain cases the zrefresh()
+	 * here was screwing up the list.  Forcing it to redraw the
+	 * screen worked.  The case in question (courtesy of
+	 * "Matt Wozniski" <godlygeek@gmail.com>) is in zsh-workers/24756.
+	 *
+	 * *** PLEASE DON'T ASK ME WHY THIS IS NECESSARY ***
+	 */
+	mlbeg = -1;
 	showinglist = ((validlist && !nolist) ? -2 : 0);
 	onlyexpl = oe;
 	if (!smatches)

-- 
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/