RESOLVED INVALID 126646
Subpixel layout: desiredColumnWidth in RenderBlock::calcColumnWidth() needs flooring. 
https://bugs.webkit.org/show_bug.cgi?id=126646
Summary Subpixel layout: desiredColumnWidth in RenderBlock::calcColumnWidth() needs f...
zalan
Reported 2014-01-08 10:46:06 PST
LayoutUnit desiredColumnWidth = std::max<LayoutUnit>(0, ((availWidth - ((desiredColumnCount - 1) * colGap)) / desiredColumnCount)) produces different CSS pixel results when subpixel is off. failed case: fast/events/document-elementFromPoint.html fast/multicol/break-properties.html fast/multicol/column-break-with-balancing.html fast/multicol/float-paginate-complex.html fast/multicol/layers-in-multicol.html fast/multicol/overflow-across-columns-percent-height.html fast/multicol/overflow-across-columns.html fast/multicol/overflow-unsplittable.html fast/multicol/scrolling-overflow.html fast/multicol/span/clone-flexbox.html fast/multicol/span/clone-summary.html fast/multicol/table-vertical-align.html fast/multicol/vertical-lr/break-properties.html fast/multicol/vertical-lr/column-break-with-balancing.html fast/multicol/vertical-lr/float-multicol.html fast/multicol/vertical-rl/break-properties.html fast/multicol/vertical-rl/column-break-with-balancing.html fast/multicol/vertical-rl/float-multicol.html fast/multicol/newmulticol/column-rules-fixed-height.html fast/multicol/newmulticol/columns-shorthand-parsing.html fast/multicol/newmulticol/layers-in-multicol.html
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zalan
Comment 1 2014-01-08 11:17:28 PST
If we start snapping columns widths to CSS pixels, we lose subpixels while layouting the columns content.
Simon Fraser (smfr)
Comment 2 2014-01-08 15:22:04 PST
Need to talk to Dave Hyatt.
zalan
Comment 3 2014-01-14 16:39:33 PST
Matches FF(v26) rendering.
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