On Mon, Nov 21, 2016 at 06:25:29PM +0000, Jürgen Hartmann wrote: > > It's really complicated, but let me try to explain what's going > > on, in case we need to understand why I made the current patch - > > at some time in the distant future. > > [Very thorough and enlightening explanation skipped.] > > > Duh. > > > > Obviously vmplayer cannot handle this strange situation and ends > > up with no window mapped. > > Thank you for this comprehensive explanation including references for further > reading (ICCCM2). > > > As far as I understand it, HandleUnmapNotify() is broken at least > > since the day in 1998 when the fvwm sources were moved to CVS. > > I've spent much time thinking about this, reading the ICCCM2 and > > the Xlib manuals, and now I'm convinced that HandleUnmapNotify() > > must never unmap the client window itself. (The *icon* window is > > a different story.) However, since there's no documentation about > > this bit of code, it's hard to guess whether there are or were > > really broken clients that needed this buggy window manager > > behaviour. Anyway, if there are such clients, they won't work on > > any modern window manager. > > > > Over the years there were several patches to fix problems caused > > by unmapping windows in HandleUnmapNotify, but none of us ever > > figured out the real bug for more than fifteen years. :-/ > > So this fix of yours really seems to be a big step. > > How would you judge its behavior concerning stability and side effects: > Would it be to risky to use it right away in a production system, aka > "testing under wild life conditions"?
The worst that can happen is that different windows aren't accessible. Regarding stability, I'd say the patched code is how it should have been from the start, but you never know what strange and broken applications are around and how they react to changes in the events before you just try it for a while. This certainly needs testing. However, this patch only affects clients that do things like iconifying or withdrawing their windows, i.e. the vast majority of programs won't be affected, but you never know what closed source programs until they break. Ciao Dominik ^_^ ^_^ -- Dominik Vogt
