vertical-rl columns don't repaint properly when there is overflow out the left side of the column set.
Created attachment 233005 [details] Patch
Attachment 233005 [details] did not pass style-queue: ERROR: Source/WebCore/rendering/RenderLayer.cpp:5109: Weird number of spaces at line-start. Are you using a 4-space indent? [whitespace/indent] [3] Total errors found: 1 in 2 files If any of these errors are false positives, please file a bug against check-webkit-style.
It seems partially this patch is implemented - https://searchfox.org/wubkat/source/Source/WebCore/rendering/RenderMultiColumnSet.cpp#735 Do we need to do anything more here? Thanks!