[webkit-changes] [WebKit/WebKit] 7e8fe9: threejs.org renders mostly blank (lazy image loadi...

[Alan Baradlay]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 7e8fe9be9b2266454fc088151004b49c49535cf8
      https://github.com/WebKit/WebKit/commit/7e8fe9be9b2266454fc088151004b49c49535cf8
  Author: Alan Baradlay <zalan at apple.com>
  Date:   2022-12-08 (Thu, 08 Dec 2022)

  Changed paths:
    A LayoutTests/fast/text/line-height-zero-with-inline-level-content-expected.html
    A LayoutTests/fast/text/line-height-zero-with-inline-level-content.html
    M Source/WebCore/layout/formattingContexts/inline/InlineFormattingGeometry.cpp

  Log Message:
  -----------
  threejs.org renders mostly blank (lazy image loading inside 0-height inline is broken?)
https://bugs.webkit.org/show_bug.cgi?id=246060
rdar://99905638

Reviewed by Antti Koivisto.

This part of the "inline level box affects the line box height" logic is a leftover from when
we used the notion of "setIsNonEmpty" to decide if an inline level box should be taken into account
at line box sizing (see webkit.org/b/218767 216957 and 220232).
However with the most recent "layout bounds" approach, ignoring "empty" atomic inline level boxes is incorrect.
While an inline level box with zero height produces the layout bounds of (0, 0), it may still put constraint on
the line box when a non-normal "line-height" triggers negative layout bounds on the inline boxes (most notably on the root inline box).
(Like in this case the root inline box ends up with the layout bounds of [5, -5] (triggered by line-height: 0) but
merging it with the <img>'s [0, 0] layout bounds will still produce a 5px tall line box).

* LayoutTests/fast/text/line-height-zero-with-inline-level-content-expected.html: Added.
* LayoutTests/fast/text/line-height-zero-with-inline-level-content.html: Added.
* Source/WebCore/layout/formattingContexts/inline/InlineFormattingGeometry.cpp:
(WebCore::Layout::InlineFormattingGeometry::inlineLevelBoxAffectsLineBox const):

Canonical link: https://commits.webkit.org/257565@main