Bug 299727

Summary:

Missing paint invalidation of area previously covered by a repositioned element

Product:

WebKit

Reporter:

Jonas Walldén <jonasw>

Component:

Compositing

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED DUPLICATE

Severity:

Normal

CC:

simon.fraser

Priority:

Version:

Safari 26

Hardware:

Mac (Apple Silicon)

OS:

macOS 26

Attachments:

Description	Flags
Test case	none

Jonas Walldén

Reported 2025-09-29 04:58:57 PDT

Created attachment 476889 [details] Test case The attached test case creates a ruler and tracks the mouse to render a measurement value on top of the ruler. When mousing around in the window I see remnants of earlier placements still on screen. This is a regression from before version 26, and I've reproduced it in two different macOS installations: Safari 21622.1.22.11.14 running on macOS 26.0 (25A354), and Safari 20622.1.22.118.4 running on macOS 15.7 (24G222). It's also present in Safari Technology Preview r228. I've noticed three workarounds which are included in the test case as `body.workaround1`, `body.workaround2` and `body.workaround3`. They include switching from fixed to absolute positioning, disabling overflow and not setting a z-index.

Attachments
Test case (2.23 KB, text/html) 2025-09-29 04:58 PDT, Jonas Walldén	no flags	Details
View All Add attachment proposed patch, testcase, etc.

Jonas Walldén

Comment 1 2025-09-29 05:03:22 PDT

*** This bug has been marked as a duplicate of bug 299728 ***

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