terminal scrolls by updating different regions out-of-sync

[Seth Arnold]

urxvt's scrolling behaviour has changed after upgrading to trusty.

Between precise and saucy, scrolling a line at a time in mutt (holding down enter) or less (also holding down enter) was smooth and easy on the eyes. In trusty, however, such scrolling is distracting because different portions of the terminal update at different rates or at different times. The effect is very 'bouncy'.

Probably the easiest way to see the issue:

Start a urxvt instance
Maximize the urxvt
Run the following command
paste /var/log/syslog /var/log/syslog /var/log/syslog | less
Hold down <enter> to scroll through the content on screen. See if any areas update oddly or otherwise bounce or vibrate.

Compare the scrolling against xterm; on my system, xterm scrolls as expected. Compare against scrolling with the wheel mouse or two-finger touch-pad scrolling; on my system, this scrolling is smooth and works as expected.

Thanks

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: rxvt-unicode 9.19-1
ProcVersionSignature: Ubuntu 3.13.0-23.45-generic 3.13.8
Uname: Linux 3.13.0-23-generic x86_64
ApportVersion: 2.14.1-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Apr 14 18:17:34 2014
InstallationDate: Installed on 2012-10-18 (543 days ago)
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
SourcePackage: rxvt-unicode
UpgradeStatus: Upgraded to trusty on 2014-04-12 (3 days ago)

[Seth Arnold (seth-arnold)]

I initially thought this was about left-half vs right-half of the terminal, but I found that the tearing line is actually fixed with respect to my monitor -- maximizing the window shows three different tearing sections, roughly spaced at 1/3 intervals on the screen. The left and right segments act the same, the center segment acts differently.

Thanks