Bug 209624

Summary:	[ Mac wk2 ] tiled-drawing/scrolling/fixed/four-bars-zoomed.html is flaky failing.
Product:	WebKit	Reporter:	Jason Lawrence <Lawrence.j>
Component:	Scrolling	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	rackler, webkit-bot-watchers-bugzilla, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Mac
OS:	macOS 10.14

Description Jason Lawrence 2020-03-26 15:51:15 PDT

tiled-drawing/scrolling/fixed/four-bars-zoomed.html

Description:
This test is flaky failing on Mac wk2 Release. When scrolling back through the visible history, it appears that the test was previously failing consistently and then started to flaky fail on 03/19/2020.

History:
https://results.webkit.org/?suite=layout-tests&test=tiled-drawing%2Fscrolling%2Ffixed%2Ffour-bars-zoomed.html&flavor=wk2&style=release

Diff:
--- /Volumes/Data/slave/catalina-release-tests-wk2/build/layout-test-results/tiled-drawing/scrolling/fixed/four-bars-zoomed-expected.txt
+++ /Volumes/Data/slave/catalina-release-tests-wk2/build/layout-test-results/tiled-drawing/scrolling/fixed/four-bars-zoomed-actual.txt
@@ -56,9 +56,9 @@
       (coverage rect 0.00, 0.00 341.30 x 254.35)
       (intersects coverage rect 1)
       (contentsScale 2.30)
-      (tile cache coverage 0, 0 341 x 445)
-      (tile size 785 x 512)
-      (top left tile 0, 0 tiles grid 1 x 2)
+      (tile cache coverage 0, 0 445 x 445)
+      (tile size 512 x 512)
+      (top left tile 0, 0 tiles grid 2 x 2)
       (in window 1)
       (children 4
         (GraphicsLayer

Comment 1 Radar WebKit Bug Importer 2020-03-26 15:51:36 PDT

<rdar://problem/60940236>

Comment 2 Jason Lawrence 2020-03-26 15:57:40 PDT

I have marked this test as failing while this issue is investigated. 
https://trac.webkit.org/changeset/259088/webkit

Comment 3 Karl Rackler 2020-07-23 05:39:19 PDT

I have marked debug additionally as this test as failing while this issue is investigated.
https://trac.webkit.org/changeset/264757/webkit

Comment 4 Karl Rackler 2020-07-23 05:44:46 PDT

REGRESSION: [ macOS wk2 ] tiled-drawing/scrolling/fixed/four-bars-zoomed.html is a flaky failure

Description:
tiled-drawing/scrolling/fixed/four-bars-zoomed.html

This started approximately 06/12/20 and has been a flaky failure since.

History:
https://results.webkit.org/?suite=layout-tests&test=tiled-drawing%2Fscrolling%2Ffixed%2Ffour-bars-zoomed.html&flavor=wk2&platform=mac&style=debug&limit=50000

Diff:
--- /Volumes/Data/slave/catalina-debug-tests-wk2/build/layout-test-results/tiled-drawing/scrolling/fixed/four-bars-zoomed-expected.txt
+++ /Volumes/Data/slave/catalina-debug-tests-wk2/build/layout-test-results/tiled-drawing/scrolling/fixed/four-bars-zoomed-actual.txt
@@ -56,9 +56,9 @@
       (coverage rect 0.00, 0.00 341.30 x 254.35)
       (intersects coverage rect 1)
       (contentsScale 2.30)
-      (tile cache coverage 0, 0 341 x 445)
-      (tile size 785 x 512)
-      (top left tile 0, 0 tiles grid 1 x 2)
+      (tile cache coverage 0, 0 445 x 445)
+      (tile size 512 x 512)
+      (top left tile 0, 0 tiles grid 2 x 2)
       (in window 1)
       (children 4
         (GraphicsLayer