[webkit-changes] [WebKit/WebKit] c2e83f: [css-grid] adjustGridPositionsFromStyle should set...

[Sammy Gill]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: c2e83fc185932b1b09c3ef4d75468cf47b2515d2
      https://github.com/WebKit/WebKit/commit/c2e83fc185932b1b09c3ef4d75468cf47b2515d2
  Author: Sammy Gill <sammy.gill at apple.com>
  Date:   2023-09-27 (Wed, 27 Sep 2023)

  Changed paths:
    M LayoutTests/TestExpectations
    M Source/WebCore/rendering/style/GridPositionsResolver.cpp

  Log Message:
  -----------
  [css-grid] adjustGridPositionsFromStyle should set a subgrid's indefinite span to use the null string
https://bugs.webkit.org/show_bug.cgi?id=260527
rdar://114271485

Reviewed by Matt Woodrow.

If a subgrid has an indefinite span in the subgridded dimension,
adjustGridPositionsFromStyle will attempt to set the span size based
on the the number of named lines that it has. This is done with a call
similar to span.setSpanPosition(std::max(1, lineCount - 1), emtpyString()).

This code presumably does not want to set the m_namedGridLine portion
of the GridPosition as we are not actually referencing a named grid
line. However, we should probably be using String() here instead of
emptyString() to set that value to the null string as the rest of the
code checks against !position.namedGridLine().isNull() when attempting
to use the named grid line. This change helps us avoid entering code
guarded by that type of logic when we probably do not want to.

* LayoutTests/TestExpectations:
* Source/WebCore/rendering/style/GridPositionsResolver.cpp:
(WebCore::adjustGridPositionsFromStyle):

Canonical link: https://commits.webkit.org/268510@main