Bug 118026 – CSS clip property should not force additional clamping to border box

• Status: NEW
• Component: Layout and Rendering

[Ryosuke Niwa]

Merge https://chromium.googlesource.com/chromium/blink/+/3f848e4438bc0c6da76778a91761d61fcc3bd2e8

For a composited layer computing its bounds, there is a code path that
clamps a layer's cliprect to the corresponding element's border box.
However, this is incorrect, since a CSS clip may have valid bounds that
include things outside the border box. So, that clamping should only occur
if there is an overflow clip.

[Ryosuke Niwa]

Also merge https://chromium.googlesource.com/chromium/blink/+/bb121b3868296b08830181e1787ae6da1a7d6609

[Ahmad Saleem]

Renamed to - hasNonVisibleOverflow after this commit:

https://github.com/WebKit/WebKit/commit/10c7d6957a522b7a2db927f31f4c45b17ab02378

Change here - https://github.com/WebKit/WebKit/blob/5730d5c8fb455166bc00aaaef3689b3d07dcdc34/Source/WebCore/rendering/RenderLayer.cpp#L4550

} else {

to 

} else if (renderer()-> hasNonVisibleOverflow()) {

^ This was revert back to original in below:

______


In other, no need to change this because it already has hasNonVisibleOverflow:

https://github.com/WebKit/WebKit/blob/5730d5c8fb455166bc00aaaef3689b3d07dcdc34/Source/WebCore/rendering/RenderLayer.cpp#L4424

and not sure on what to do here:

https://github.com/WebKit/WebKit/blob/5730d5c8fb455166bc00aaaef3689b3d07dcdc34/Source/WebCore/rendering/RenderLayer.cpp#L4428

and this can be removed (hasClip):

https://github.com/WebKit/WebKit/blob/5730d5c8fb455166bc00aaaef3689b3d07dcdc34/Source/WebCore/rendering/RenderLayer.cpp#L4445

and this FIXME need to be updated:

https://github.com/WebKit/WebKit/blob/5730d5c8fb455166bc00aaaef3689b3d07dcdc34/Source/WebCore/rendering/RenderLayer.cpp#L4542

and add remaining bits here:

https://github.com/WebKit/WebKit/blob/5730d5c8fb455166bc00aaaef3689b3d07dcdc34/Source/WebCore/rendering/RenderLayer.cpp#L4560