The canvas is positioned incorrectly in (at least) Firefox 39 on Android after doing this: - Start a session in the normal 1:1 mode - Reconfigure the desktop to something larger - Pan a bit - Rotate the device to trigger a resize The canvas will now be positioned incorrectly by the same amount as the panning that was previously performed. The "dead" areas exposed show old data, rather than some background colour, so this might be a browser bug. OTOH, we're not behaving very nice by fighting with the browser over the canvas position so this might be an undefined corner case.
Seeing the same issue on Chrome 46 on Android.
Fixed in upstream noVNC by double buffering: https://github.com/novnc/noVNC/pull/699
This is fixed now.
Verified that i could reproduce the issue against our internal 4.7.0 server using Firefox 50.1.0 and Chrome 56.0.2924.87 on android. Did the same tests against 4.7.0post 5365 and the problem is not reproducible. Works as expected.