Version: (using KDE KDE 3.1.4) Installed from: Gentoo Packages OS: Linux If you use krfb on a remote X-server then the viewer only gets a black screen. You are still able to control the mouse and keyboard but you don't see anything. Is this a limitation of X?
This is a problem of your X11 server. Unfortunately some X11 servers (especially X11 terminals) claim to support the XShm extension and then just provide black images. But as you are not the only one I should add an option to the configuration panel to turn XShm off. Currently it is detected automatically, but if the server lies the detection fails.
Implemented the option.
Do you have any information about which X11 server doesn't "lie" about XShm? I've only tested different recent Versions of XFree86 on different platforms (SuSE, Gentoo, Igel Thin Clients)... all with the same result. What is the alternative of using the XShm extension? (I'm not very familiar with the X protocol)
> What is the alternative of using the XShm extension? I've just browsed the CVS source and now it's a little clearer to me. I've thougt that XShm is a prerequisite for using krfb but that's not the case. It's an alternative (faster?) way of getting the image data but if the X server lies about it... It should work now?
> ... I should add an option to the configuration panel to turn XShm off I wonder if XShm for a for a remote display is possible at all. If it's possible then there should be an option. But if it's not possible (and I think so) XShm should be turned off gererally for remote displays. btw: i've disabled the use of XShm in xupdatescanner.cc and it works now :-)
So far I have thought that it was a problem of some X11 terminals, but XFree got me thinking... probably I also need to check for the XShm version in order to make it work. I'll try that. And yes, XShm is used for performance and only possible on a local system. Wth XShm krfb can access the framebuffer directly.
Committed the new detection mechanism. (BTW forgot to commit the kcontrol module for manual XShm disabling yesterday, but it is hopefully not neccessary with the new code anyway)
*** Bug 73825 has been marked as a duplicate of this bug. ***
Still doesn't seem to be fixed in all cases. This exact problem is occurring on Fedore Core 2 stock install. Any attempt to use krfb/krdc results in a black screen on the krdc side (although a brief 8-bit picture appears). All other functionality seems to be working fine; ie - I can move the mouse, bring up menus and start apps on the distant (krfb) end, I just can't see what I am doing on the local (krdc) side.