I do not understand what you mean with closing a second desktop window and which toolbar? Could you please very precisely explain what you did when the window manager crashed?

"Toolbar" == "Titlebar" == "what users think, kwin is"

He apparently reduced the number of VD from two to one.
As consequence the windows on the second VD were moved to the first one and that causes an out of bounds (?!) access in QVector.

However i checked the code and because "desk" in
> KWin::Workspace::sendClientToDesktop (this=0x137aef0, c=<optimized out>, desk=1, dont_activate=<optimized out>) 
is actually numberOfDesktops() and that value is also used to allocate the vector in question (+1 because the code uses client::desktop() and that starts counting at one) this is either a stack corruption (somewhere else) or a downstream fix or a bug in Qt?

at least this pointer:
> #6  operator!= (this=0x30, value=1) at /usr/include/qt4/QtCore/qbasicatomic.h:75
is obviously junk

@gbappleton
a) can you reproduce this at will?
b) do you use window tabbing or tiling?

You have interpreted my obviously incoherent report correctly and
succinctly, proving once again that knowing the precise language is
essential for communication in any technical field. I did use window
tabbing (if you mean what I think you mean, The problem was repeatable ,
but disappeared after doing a hard reboot. Since I learned programming in
Fortran and Cobol on an old Honeywell mainframe, and went on an almost
Luddite strike with the demise of dos5 and the creation of.com domains, my
familiarity with modern programming is very limited. I used to work
comfortably on FreeBSD and early releases of Linux, I have been forced
accept that my current skill level is only fit for running an advanced
abacus. Can you perhaps recommend a good starting text/ reference to linux
and modern high level languages? I doubt that I am even capable of
memorizing the man pages, now that I am retired and drifting slowly but
steadily into an almost pleasant senility. Thank you for your help and
would appreciate any assitance in bringing my skill set into the 21st
century.
Sincerely,
         gary
gbappleton@gmail.com

On Mon, Aug 20, 2012 at 3:50 PM, Thomas Lübking
<thomas.luebking@gmail.com>wrote:

> https://bugs.kde.org/show_bug.cgi?id=305499
>
> --- Comment #2 from Thomas Lübking <thomas.luebking@gmail.com> ---
> "Toolbar" == "Titlebar" == "what users think, kwin is"
>
> He apparently reduced the number of VD from two to one.
> As consequence the windows on the second VD were moved to the first one and
> that causes an out of bounds (?!) access in QVector.
>
> However i checked the code and because "desk" in
> > KWin::Workspace::sendClientToDesktop (this=0x137aef0, c=<optimized out>,
> desk=1, dont_activate=<optimized out>)
> is actually numberOfDesktops() and that value is also used to allocate the
> vector in question (+1 because the code uses client::desktop() and that
> starts
> counting at one) this is either a stack corruption (somewhere else) or a
> downstream fix or a bug in Qt?
>
> at least this pointer:
> > #6  operator!= (this=0x30, value=1) at
> /usr/include/qt4/QtCore/qbasicatomic.h:75
> is obviously junk
>
> @gbappleton
> a) can you reproduce this at will?
> b) do you use window tabbing or tiling?
>
> --
> You are receiving this mail because:
> You reported the bug.
>

Extrapolite ;-)

By "tabbing" i meant the feature where you can stack two or more windows into one titlebar.
The implementation used in 4.8 is... sorry, but i don't know a polite word for that =)

You should consider to either avoid it or upgrade to 4.9 (feature rewritten) or even better upcoming 4.9.1 (fixed some minor issues) because _all_ versions before are knowingly prone to corrupt the stack.

It's however not certain that this is the cause, so keep an eye on it and in case you get similar crashes (esp. with 4.9), please keep us posted.

Virtual desktop handling has been rewritten for 4.11 with a2a335064e206f0689e315d58c30bedce90decff. Although we cannot be sure what actually caused the crash we can assume that it is fixed by now either through the window tabbing improvements in 4.9 or the improvements for virtual desktops in 4.11

thank you
                 gary


On Mon, Jan 7, 2013 at 12:30 PM, Martin Gräßlin <mgraesslin@kde.org> wrote:

> https://bugs.kde.org/show_bug.cgi?id=305499
>
> Martin Gräßlin <mgraesslin@kde.org> changed:
>
>            What    |Removed                     |Added
>
> ----------------------------------------------------------------------------
>              Status|UNCONFIRMED                 |RESOLVED
>          Resolution|---                         |FIXED
>
> --- Comment #5 from Martin Gräßlin <mgraesslin@kde.org> ---
> Virtual desktop handling has been rewritten for 4.11 with
> a2a335064e206f0689e315d58c30bedce90decff. Although we cannot be sure what
> actually caused the crash we can assume that it is fixed by now either
> through
> the window tabbing improvements in 4.9 or the improvements for virtual
> desktops
> in 4.11
>
> --
> You are receiving this mail because:
> You reported the bug.
>