Fix contain-size-monolithic-002.html.
Created attachment 462230 [details] Patch
Is this is the same bug as bug 238854?
Bug 238854 has a testcase of the bug without CSS containment, so ideally the fix would be fixing that testcase as well.
Bug 41796 is related as well.
Created attachment 462295 [details] Patch
Created attachment 462319 [details] Patch
(In reply to Tim Nguyen (:ntim) from comment #4) > Bug 41796 is related as well. Thanks Tim, I knew about this one but not bug 238854.
@Alan I noticed fragmentedFlowPortionOverflowRect does not include column gap. My patch adds the column gap later on to paginationClip so we include the column gap when clipping for painting columns in RenderLayer and thus fixes contain-size-monolithic-002.html and bug 41796 test case. However I do not know this code very well. In general, do you know how clipping should work for multicol? For example I notice for some reason the bug 238854 test case is not clipped to the total column bounds in chromium, but is in Firefox. I also wonder if out of flow content is clipped at all in multcol.
(In reply to Rob Buis from comment #8) > @Alan I noticed fragmentedFlowPortionOverflowRect does not include column > gap. My patch adds the column gap later on to paginationClip so we include > the column gap when clipping for painting columns in RenderLayer and thus > fixes contain-size-monolithic-002.html and bug 41796 test case. However I do > not know this code very well. In general, do you know how clipping should > work for multicol? No, I don't know too much about clipping in general. Maybe Simon? For example I notice for some reason the bug 238854 test > case is not clipped to the total column bounds in chromium, but is in > Firefox. I also wonder if out of flow content is clipped at all in multcol. Not sure but I'd think it's relatively easy to create a test case to confirm it.
Layer tree without the position: relative: layer 0x143003400 scrollableArea 0x10504d6c0 at (0,0) size 938x753 (composited [root], bounds=at (0,0) size 938x753, drawsContent=1, paints into ancestor=0) RenderView 0x143003120 at (0,0) size 938x753 positive z-order list (1) layer 0x143000b90 scrollableArea 0x10504d940 at (0,0) size 938x58 RenderBlock 0x143001860 {HTML} at (0,0) size 938x58 RenderBody 0x143001ad0 {BODY} at (8,16) size 922x34 RenderBlock 0x143005060 {P} at (0,0) size 922x18 RenderText 0x1430051a0 {#text} at (0,0) size 274x18 text run at (0,0) width 274: "Test passes if there is a filled green square." normal flow list (1) layer 0x1430019a0 at (8,50) size 300x0 RenderBlock 0x143005230 {DIV} at (0,34) size 300x0 id="multicol" RenderMultiColumnSet 0x143005a60 at (0,0) size 300x0 normal flow list (1) layer 0x143005930 at (8,50) size 89x0 RenderMultiColumnFlowThread 0x143005720 at (0,0) size 90x0 RenderBlock 0x143005370 {DIV} at (0,0) size 90x0 id="container" positive z-order list (1) layer 0x1430055f0 at (8,50) size 100x100 RenderBlock (positioned) 0x1430054b0 {DIV} at (8,50) size 100x100 [bgcolor=#008000] id="abs-size-contain" with position: relative: layer 0x135003400 scrollableArea 0x10504f380 at (0,0) size 938x753 (composited [root], bounds=at (0,0) size 938x753, drawsContent=1, paints into ancestor=0) RenderView 0x135003120 at (0,0) size 938x753 positive z-order list (1) layer 0x135000b90 scrollableArea 0x10504f600 at (0,0) size 938x158 RenderBlock 0x135001860 {HTML} at (0,0) size 938x158 RenderBody 0x135001ad0 {BODY} at (8,16) size 922x134 RenderBlock 0x135005060 {P} at (0,0) size 922x18 RenderText 0x1350051a0 {#text} at (0,0) size 274x18 text run at (0,0) width 274: "Test passes if there is a filled green square." normal flow list (1) layer 0x1350019a0 at (8,50) size 300x100 RenderBlock 0x135005230 {DIV} at (0,34) size 300x100 id="multicol" RenderMultiColumnSet 0x135005b90 at (0,0) size 300x100 normal flow list (1) layer 0x135005a60 at (8,50) size 89x0 RenderMultiColumnFlowThread 0x135005850 at (0,0) size 90x0 (layout overflow 0,0 100x100) positive z-order list (2) layer 0x1350054b0 at (8,50) size 89x0 RenderBlock (relative positioned) 0x135005370 {DIV} at (0,0) size 90x0 id="container" (layout overflow 0,0 100x100) layer 0x135005720 at (8,50) size 100x100 RenderBlock (positioned) 0x1350055e0 {DIV} at (0,0) size 100x100 [bgcolor=#008000] id="abs-size-contain"
<rdar://problem/100026789>
Created attachment 462399 [details] Patch
Created attachment 462407 [details] Patch
The testcase in bug 238854 still doesn't look quite right with the patch applied. The green area looks shorter than other browsers.
Created attachment 462412 [details] Screenshot of testcase in bug 238854 I think we might need to expand beyond the colGap, but to the width of the largest item in the column.
Comment on attachment 462407 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=462407&action=review > COMMIT_MESSAGE:6 > +Include the column gap when calculating the pagination clip. This comment is rather redundant.
Comment on attachment 462407 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=462407&action=review >> COMMIT_MESSAGE:6 >> +Include the column gap when calculating the pagination clip. > > This comment is rather redundant. Thanks for the review! Unfortunately, now that I look at it again, it is probably not the right fix, as the test case will fail if the div is made wider (it would still be clipped at 100px). I think the real fix is https://bugs.webkit.org/show_bug.cgi?id=238854.
Ths is fixed by the bug 238854 fix.