[webkit-changes] [WebKit/WebKit] 34c2d1: RemoteImageBufferSet::prepareBufferForDisplay uses...

[Kimmo Kinnunen]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 34c2d1233dec1417e97868ce1c575e31b7f15fbc
      https://github.com/WebKit/WebKit/commit/34c2d1233dec1417e97868ce1c575e31b7f15fbc
  Author: Kimmo Kinnunen <kkinnunen at apple.com>
  Date:   2023-12-20 (Wed, 20 Dec 2023)

  Changed paths:
    M Source/WebKit/GPUProcess/graphics/RemoteImageBufferSet.cpp

  Log Message:
  -----------
  RemoteImageBufferSet::prepareBufferForDisplay uses source rects larger than the layer bounds
https://bugs.webkit.org/show_bug.cgi?id=266628
rdar://problem/119862411

Reviewed by Matt Woodrow.

The drawImageBuffer(ib, ..., sourceRect, ..) would receive
   FloatRect sourceRect = expandedIntRect({ { }, ib->logicalSize() })

This does not make sense, it is not well defined what it means to fetch
pixels outside of the source. This should be a caller bug.
For example, the logicalSize might be 95.5 with scale = 2. The
underlying native image would be 191 pixels.

The problem was caused by dirty rect calculations with Region, which
does not support floating point dimensions.

* Source/WebKit/GPUProcess/graphics/RemoteImageBufferSet.cpp:
(WebKit::RemoteImageBufferSet::prepareBufferForDisplay):

Canonical link: https://commits.webkit.org/272330@main