[webkit-changes] [WebKit/WebKit] 71f363: [IFC][Integration][Line clamp] Block children star...

[Ethan Wong]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 71f363c22510a871c79e265d62436443c7802743
      https://github.com/WebKit/WebKit/commit/71f363c22510a871c79e265d62436443c7802743
  Author: Ethan Wong <e1hanw0ng at gmail.com>
  Date:   2023-04-18 (Tue, 18 Apr 2023)

  Changed paths:
    A LayoutTests/fast/text/layout-overflow-hidden-for-line-clamped-content-expected.html
    A LayoutTests/fast/text/layout-overflow-hidden-for-line-clamped-content.html
    M Source/WebCore/layout/integration/inline/LayoutIntegrationLineLayout.cpp

  Log Message:
  -----------
  [IFC][Integration][Line clamp] Block children starting with lines exceeding `maximumLineCountForLineClamp` should be fully collapsed.
https://bugs.webkit.org/show_bug.cgi?id=255487

Reviewed by Alan Baradlay.

`-webkit-line-clamp` expects the logical height of the content box to be
collapsed to the last visible line.

At `LineLayout::lastLineIndexForContentHeight()`, `visibleLineCountForLineClamp`
of the current layout state may be greater than `maximumLineCountForLineClamp`
when multiple children are being laid out within the same context of line clamp.
In this case, the last line index should be returned as empty in order for the
individual child block to be fully collapsed.

* LayoutTests/fast/text/layout-overflow-hidden-for-line-clamped-content-expected.html: Added.
* LayoutTests/fast/text/layout-overflow-hidden-for-line-clamped-content.html: Added.
* Source/WebCore/layout/integration/inline/LayoutIntegrationLineLayout.cpp:
(WebCore::LayoutIntegration::LineLayout::lastLineIndexForContentHeight const):

Canonical link: https://commits.webkit.org/263079@main