Bug 307582 – REGRESSION(307212@main): [iOS] compositing/overflow/rtl-scrollbar-layer-positioning.html is a constant text failure

• Component: Compositing
• Status: NEW

[Diego De La Toba]

compositing/overflow/rtl-scrollbar-layer-positioning.html is a constant text failure. Regression at 307212@main verified via bisection. 


HISTORY:
https://results.webkit.org/?suite=layout-tests&test=compositing%2Foverflow%2Frtl-scrollbar-layer-positioning.html


TEXT DIFF:
--- /Volumes/Data/worker/Apple-iOS-26-Simulator-Debug-WK2-Tests/build/layout-test-results/fast/css/target-fragment-match-expected.txt
+++ /Volumes/Data/worker/Apple-iOS-26-Simulator-Debug-WK2-Tests/build/layout-test-results/fast/css/target-fragment-match-actual.txt
@@ -5,5 +5,5 @@
     RenderBody {BODY} at (8,16) size 784x20
       RenderBlock {DIV} at (0,0) size 784x20
         RenderBlock {P} at (0,0) size 784x20
-          RenderText {#text} at (0,0) size 624x19
+          RenderText {#text} at (0,0) size 624x20
             text run at (0,0) width 624: "I should be highlighted first because of the anchor, and de-highlighted when there is no fragment."


DIFF URL:
https://build.webkit.org/results/Apple-iOS-26-Simulator-Debug-WK2-Tests/307245%40main%20(703)/fast/css/target-fragment-match-pretty-diff.html


REPRODUCTION:
I was able to reproduce this failure on an iPhone 12 simulator running iOS 26.2 ToT with the following:

run-webkit-tests --ios-simulator --child-processes=1 --no-retry --exit-after-n-failures=5 --iterations 100 compositing/overflow/rtl-scrollbar-layer-positioning.html

I am going to mark expectations as fail while this pends investigation.

[Radar WebKit Bug Importer]

<rdar://problem/170165781>

[Diego De La Toba]

CORRECTED DIFF AND URL:
https://build.webkit.org/results/Apple-iOS-26-Simulator-Debug-WK2-Tests/307245%40main%20(703)/compositing/overflow/rtl-scrollbar-layer-positioning-pretty-diff.html

--- /Volumes/Data/worker/Apple-iOS-26-Simulator-Debug-WK2-Tests/build/layout-test-results/compositing/overflow/rtl-scrollbar-layer-positioning-expected.txt
+++ /Volumes/Data/worker/Apple-iOS-26-Simulator-Debug-WK2-Tests/build/layout-test-results/compositing/overflow/rtl-scrollbar-layer-positioning-actual.txt
@@ -15,14 +15,14 @@
             (GraphicsLayer
               (offsetFromRenderer width=13 height=13)
               (position 23.00 23.00)
-              (bounds origin 292.00 0.00)
+              (bounds origin 300.00 0.00)
               (bounds 316.00 316.00)
               (children 1
                 (GraphicsLayer
                   (offsetFromRenderer width=13 height=13)
-                  (scrollOffset (292,0))
+                  (scrollOffset (300,0))
                   (anchor 0.00 0.00)
-                  (bounds 608.00 616.00)
+                  (bounds 616.00 616.00)
                 )
               )
             )

[Alexey Proskuryakov]

This updated diff makes it look like something is truly wrong with scrollbar, and it's not for rebaselining.

[Diego De La Toba]

Pull request: https://github.com/WebKit/WebKit/pull/58550

[EWS]

Test gardening commit 307407@main (ff0c84b551c9): <https://commits.webkit.org/307407@main>

Reviewed commits have been landed. Closing PR #58550 and removing active labels.