tree 03d456881e5d27cc6de1ac956ac377c71548092c
parent 91593e66e79885911d0e937006b3efc6c4d33cae
author zalan@apple.com <zalan@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1643241227 +0000
committer zalan@apple.com <zalan@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1643241227 +0000

REGRESSION (r281306): Non-breaking space incorrectly collapsed when webkit-nbsp-mode is set to "space"
https://bugs.webkit.org/show_bug.cgi?id=235627
<rdar://88004831>

Reviewed by Antti Koivisto.

Source/WebCore:

"-webkit-nbsp-mode: space" has a peculiar collapsing behavior. It only collapses as leading content
preceded by forced line break.

<div style="-webkit-nbsp-mode: space; width: 0px;">
  first_line&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;second_line
</div>
The non-breaking space is collapsed. It does not show on the second line as leading content.

<div style="-webkit-nbsp-mode: space; width: 0px;">
  first_line<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;second_line
</div>
The non-breaking space is NOT collapsed. It shows up as leading content on the second line, indenting the "second_line" text content.

To mimic this legacy behavior, it's easier just to switch back to handling nbsp; as a non-whitespace inline item and
collapse it as leading content (depending on the breaking context).
(as opposed to customize regular whitespace content collapsing behavior just to support this quirk)

Test: fast/text/collapsible-non-breaking-space.html

* layout/formattingContexts/inline/InlineItemsBuilder.cpp:
(WebCore::Layout::moveToNextNonWhitespacePosition): remove special nbsp; handling
(WebCore::Layout::InlineItemsBuilder::handleTextContent): create an inline text item for the special mon-breaking space content.
* layout/formattingContexts/inline/InlineLine.cpp:
(WebCore::Layout::Line::initialize):
(WebCore::Layout::Line::appendTextContent):
* layout/formattingContexts/inline/InlineLine.h:
* layout/formattingContexts/inline/InlineLineBuilder.cpp:
(WebCore::Layout::LineBuilder::inlineItemWidth const):
(WebCore::Layout::LineBuilder::initialize):
(WebCore::Layout::LineBuilder::candidateContentForLine):
(WebCore::Layout::LineBuilder::handleInlineContent):
(WebCore::Layout::LineBuilder::rebuildLine):
* layout/formattingContexts/inline/InlineLineBuilder.h:
(WebCore::Layout::LineBuilder::isFirstLine const):
* layout/formattingContexts/inline/InlineTextItem.cpp:
(WebCore::Layout::InlineTextItem::isCollapsibleNonBreakingSpace const):
* layout/formattingContexts/inline/InlineTextItem.h:

LayoutTests:

* fast/text/collapsible-non-breaking-space-expected.html: Added.
* fast/text/collapsible-non-breaking-space.html: Added.
* platform/ios/fast/text/whitespace/nbsp-mode-and-linewraps-expected.txt: A slight behavior change with trailing content trimming, but
not generally noticeable and very specific to this non-standard property.
* platform/mac/fast/text/whitespace/nbsp-mode-and-linewraps-expected.txt:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@288650 268f45cc-cd09-0410-ab3c-d52691b4dbfc