Open Radar

 
This is a duplicate of rdar://19382113

Summary:
Windows don't repaint correctly over a VNC connection. Portions of windows don't redraw and pieces of other windows are left around on screen.

Steps to Reproduce:
1. Connect to a system running 10.10.1 (14B25)
2. Use it for awhile

Expected Results:
The windows should repaint correctly

Actual Results:
Eventually the windows will fail to repaint.

Version:
10.10.1 (14B25)

Notes:
A workaround is to disable beam sync in Quartz Debug. After the beam sync is disabled, the windows repaint correctly.

Note that I can't take a screenshot of this because doing so causes all the corrupted windows to repaint.

This problem looks like the same thing that happens when using a virtual machine (like VMware) on Yosemite: https://derflounder.wordpress.com/2014/12/13/improving-yosemite-vm-performance-in-vmware-fusion/

I find this corruption whether I’m using Screens.app - Apple Screen Sharing app - Apple Remote Desktop. It’s irritating and sometimes fatal when supporting a remote server with a low bandwidth connection. Dropping the resolution only works so far and interacting with Time Machine to restore files remotely is a real pain when the screen repaint is so buggy and full of garbage when things get garbled.