[webkit-changes] [WebKit/WebKit] 223cdc: In some macOS VM configurations, layer content is ...

[Simon Fraser]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 223cdceb76379ccf7c9094c58312bbd5ec3fb944
      https://github.com/WebKit/WebKit/commit/223cdceb76379ccf7c9094c58312bbd5ec3fb944
  Author: Simon Fraser <simon.fraser at apple.com>
  Date:   2023-08-10 (Thu, 10 Aug 2023)

  Changed paths:
    M Source/WebCore/platform/graphics/cocoa/IOSurface.mm

  Log Message:
  -----------
  In some macOS VM configurations, layer content is sometimes missing
https://bugs.webkit.org/show_bug.cgi?id=260003
<rdar://112875397>

Reviewed by Tim Horton.

In some macOS VM configs without accelerated graphics, IOSurfaceGetPropertyMaximum()
returns INT_MAX. This resulted in `TileController::computeTileSize()` sometimes computing
negative tile widths, which resulted in missing content.

Fix by clamping to fallbackMaxSurfaceDimension(), which is something we already did on iOS;
on macOS this will clamp to a max of 32K, which prevents the INT_MAX causing math errors.

* Source/WebCore/platform/graphics/cocoa/IOSurface.mm:
(WebCore::computeMaximumSurfaceSize):

Canonical link: https://commits.webkit.org/266767@main