[webkit-changes] [WebKit/WebKit] 997b59: Bitmap-only layers sometimes get stuck with empty ...

[Tim Horton]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 997b59a25b4cf0e265fc3d918592b9a535e9108a
      https://github.com/WebKit/WebKit/commit/997b59a25b4cf0e265fc3d918592b9a535e9108a
  Author: Tim Horton <timothy_horton at apple.com>
  Date:   2023-04-24 (Mon, 24 Apr 2023)

  Changed paths:
    M Source/WebCore/platform/graphics/cocoa/WebCoreCALayerExtras.h
    M Source/WebCore/platform/graphics/cocoa/WebCoreCALayerExtras.mm
    M Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.mm

  Log Message:
  -----------
  Bitmap-only layers sometimes get stuck with empty CG display lists
https://bugs.webkit.org/show_bug.cgi?id=255796
rdar://108347964

Reviewed by Dean Jackson.

When a layer transitions from having a display list to not (e.g. a layer
/becomes/ bitmap-only), we need to actually clear the existing display list.
Also ensure that we turn off all of the related CALayer bits, not just the display list.
Also remove a stale workaround.

* Source/WebCore/platform/graphics/cocoa/WebCoreCALayerExtras.h:
* Source/WebCore/platform/graphics/cocoa/WebCoreCALayerExtras.mm:
(-[CALayer _web_clearContents]):
(-[CALayer _web_clearCGDisplayListIfNeeded]):
* Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.mm:
(WebKit::RemoteLayerBackingStoreProperties::applyBackingStoreToLayer):

Canonical link: https://commits.webkit.org/263317@main