242550 2022-07-08 20:47:32 -0700 A vertical scrollbar is shown when none is necessary 2023-05-04 13:43:24 -0700 1 1 1 Unclassified WebKit Layout and Rendering Safari Technology Preview Unspecified Unspecified NEW https://bugs.webkit.org/show_bug.cgi?id=256298 InRadar P2 Normal --- 1 simon.fraser webkit-unassigned bfulgham simon.fraser webkit-bug-importer zalan oldest_to_newest 1881856 0 460775 simon.fraser 2022-07-08 20:47:32 -0700 Created attachment 460775 Testcase When the content size matches the view size (or the iframe size), then we'll create a vertical scrollbar and trigger vertical scrolling when it's not necessary (when scrollbars take space, i.e. non-overlay scrollbars). Turn on always-on scrollbars. Load the attached testcase Size the window so that the gray rectangle just covers the web view. Reload; note how a vertical scrollbar appears. Now size the window from the bottom, making it slightly taller then shorter, back to the original size. Note how you can make the scrollbar go away. 1881857 1 simon.fraser 2022-07-08 20:48:27 -0700 This is about code in in `FrameView::adjustScrollbarsForLayout()` that forces on the vertical scrollbar for the first layout, but doesn't compute that it can remove it again and still fit the content. The state is unstable; some future layout can cause the scrollbar to disappear. 1884519 2 webkit-bug-importer 2022-07-15 20:48:14 -0700 <rdar://problem/97108398> 460775 2022-07-08 20:47:32 -0700 2022-07-08 20:47:32 -0700 Testcase exact-fit-scrollbars.html text/html 781 simon.fraser PCFET0NUWVBFIGh0bWw+CjxodG1sPgo8aGVhZD4KICAgIDxtZXRhIG5hbWU9InZpZXdwb3J0IiBj b250ZW50PSJ3aWR0aD1kZXZpY2Utd2lkdGgsIGluaXRpYWwtc2NhbGU9MSwgc2hyaW5rLXRvLWZp dD1ubyI+CiAgICA8c3R5bGU+CiAgICAgICAgaHRtbCB7CiAgICAgICAgICAgICBmb250LXNpemU6 IDIwcHg7CiAgICAgICAgICAgICBsaW5lLWhlaWdodDogMjBweDsKICAgICAgICAgICAgIGJhY2tn cm91bmQtaW1hZ2U6IGxpbmVhci1ncmFkaWVudChzaWx2ZXIsIHNpbHZlcik7CiAgICAgICAgICAg ICBiYWNrZ3JvdW5kLXNpemU6IDYwOHB4IDI4MnB4OwogICAgICAgICAgICAgYmFja2dyb3VuZC1y ZXBlYXQ6IG5vLXJlcGVhdDsKICAgICAgICB9CiAgICAgICAgCiAgICAgICAgYm9keSB7CiAgICAg ICAgICAgIG1hcmdpbjogMDsKICAgICAgICB9CiAgICA8L3N0eWxlPgo8L2hlYWQ+Cjxib2R5Pgog ICAgPGRpdj54eDwvZGl2PgogICAgPGRpdj54eDwvZGl2PgogICAgPGRpdj54eHh4eHh4eHh4eHh4 eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eCB6PC9kaXY+CiAg ICA8ZGl2Pnh4PC9kaXY+CiAgICA8ZGl2Pnh4PC9kaXY+CiAgICA8ZGl2Pnh4PC9kaXY+CiAgICA8 ZGl2Pnh4PC9kaXY+CiAgICA8ZGl2Pnh4PC9kaXY+CiAgICA8ZGl2Pnh4PC9kaXY+CiAgICA8ZGl2 Pnh4PC9kaXY+CiAgICA8ZGl2Pnh4PC9kaXY+CiAgICA8ZGl2Pnh4PC9kaXY+CiAgICA8ZGl2Pnh4 PC9kaXY+CiAgICA8ZGl2Png8L2Rpdj4KPC9ib2R5Pgo8L2h0bWw+Cg==