Tests ----- http://test.csswg.org/suites/css-writing-modes-3_dev/nightly-unstable/html/form-controls-vrl-005.htm http://test.csswg.org/suites/css-writing-modes-3_dev/nightly-unstable/html/form-controls-vlr-005.htm http://test.csswg.org/suites/css-writing-modes-3_dev/nightly-unstable/html/form-controls-srl-005.htm Step ---- Make the <textarea> as wide as you can and then narrow it down slowly: try to horizontally-only narrow it down. Actual ------ The right border of the <textarea> gets repainted intermittently, creating a residual painting trace Expected -------- The right border of the <textarea> should not be repainted intermittently, therefore it should not create a residual painting trace Explanation ----------- This layout issue can be reproduced in tests with 'writing-mode: horizontal-tb'. Other form controls can be affected by a resizing <textarea>; <input type="text"> can also start painting its left or right border intermittently as/if its horizontal position changes, moves leftwardedly (from right toward left) Notes ----- - Severity set to minor - this spun from bug 1272997 comment 3 and bug 1272997 comment 5 - Another test with 'writing-mode: horizontal-tb' is coming up - I am using Firefox 49.0a1 buildID=20160520030251 - I use Linux 3.13.0-86-generic x86_64, Qt: 4.8.6, KDE 4.13.3; Kubuntu (trusty) 14.04.4 LTS - I've searched for duplicates and did not find any.
I do not know for sure if this bug affects Windows and/or Mac OS X. So, I'm marking this Linux-only for now.
Firefox 46.0.1 buildID=20160511224433 and Firefox 48.0a1 buildID=20160401175617 (both under Linux) also render actual results. Screenshots available if requested.