Re: [ANNOUNCE] Sawfish 1.6.1 "Astral". : sawfish restart bugs, short report.

[Janek Kozicki <janek_listy wp pl>]

Michal Jaegermann said:     (by the date of Sat, 23 Jan 2010 08:56:53 -0700)

> On Sat, Jan 23, 2010 at 02:27:22PM +0900, Teika Kazura wrote:
> > On Wed, 20 Jan 2010 21:41:27 +0100, Janek Kozicki wrote:
> > > 
> > > I verified it even more precisely. This breaks exactly after 32768th
> > > pixel is exceeded. Therefore: after 'sawfish restart' all windows
> > > (except the maximized ones) are in their correct position. But if I
> > > try to move windows that are far-right (after 2^15 pixels) they behave
> > > wrongly. Which can be quickly fixed with grow-pack.
> > 
> > That's nasty. Why? You know, in Xinerama.h, there's in fact short:
> > 
> > typedef struct {
> >    int   screen_number;
> >    short x_org;
> >    short y_org;
> >    short width;
> >    short height;
> > } XineramaScreenInfo;
> > 
> > I don't know what exactly happens in C integer comparison, but as far
> > as I tested the other day, it's harmless. No?
> 
> What do you mean by "harmless"?  If you will take some short value
> and you will add something to it to cross 2^15 boundary then a
> result will end up smaller than the original.  I did not look closer
> but it sounds like that this is something which happens to Janek.
> 
> > (These short values
> > are accessed in "find-head" in src/functions.c.)


I think that this bug is not xinerama dependent. I suppose, that you
can reproduce it in following manner:

1. create large viewport-dimensions, like in ~/.sawfishrc

  (define-special-variable viewport-dimensions '(100 . 100)
    "Size of each virtual workspace.")

2. go to far away viewport, open an xterm in there. The pixel position
of this xterm must be above 2^15 pixels, counting from left-top 1st
viewport top corner.

3. restart sawfish (I was restarting sawfish while in viewport 1,1
this might be relevant)

4. go to aforementioned xterm, it is there. You can see it.

5. now try to move it (I assigned "move" action to alt-left click on
window - this is unlikely be relevant, but I am NOT grabbing by the
titlebar, but in the window context). Suddenly your xterm is far away.

So, did you reproduce it?

-- 
Janek Kozicki                                                         |