[LFC][IFC] Inline boxes with collapsible content only should not be c…

…onsidered opaque bidi items

https://bugs.webkit.org/show_bug.cgi?id=235447

Reviewed by Antti Koivisto.

Source/WebCore:

We don't normally submit inline boxes with content to ubidi re-ordering since their content drives the visual
position unless they are empty. While empty inline boxes do not usually produce visual artifacts (except ones with decoration)
they still need to be able to answer "bounding box" type of questions.

So in order to have geometry generated for inline boxes, they either
1, need to have some content so that while processing their content, we also compute their geometries
2, have to participate in ubidi's visual re-ordering so that they show up in the visual list (which is the input to the display box create function)

This patch treats inline boxes with fully collapsible content empty so that they fall into group #2.

* layout/formattingContexts/inline/InlineItemsBuilder.cpp:
(WebCore::Layout::InlineItemsBuilder::breakAndComputeBidiLevels):

LayoutTests:

* TestExpectations:



Canonical link: https://commits.webkit.org/246272@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@288371 268f45cc-cd09-0410-ab3c-d52691b4dbfc

LayoutTests/ChangeLog

@@ -1,3 +1,12 @@
+2022-01-21  Alan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Inline boxes with collapsible content only should not be considered opaque bidi items
+        https://bugs.webkit.org/show_bug.cgi?id=235447
+
+        Reviewed by Antti Koivisto.
+
+        * TestExpectations:
+
 2022-01-21  Robert Jenner  <Jenner@apple.com>
 
         [ iOS EWS ] imported/w3c/web-platform-tests/dom/events/focus-event-document-move.html is a constant text failure

LayoutTests/TestExpectations

@@ -2745,7 +2745,6 @@ webkit.org/b/195275 imported/w3c/web-platform-tests/css/css-text/white-space/tab
 webkit.org/b/195275 imported/w3c/web-platform-tests/css/css-text/white-space/tab-stop-threshold-006.html [ ImageOnlyFailure ]
 webkit.org/b/195275 imported/w3c/web-platform-tests/css/css-text/white-space/control-chars-000.html [ ImageOnlyFailure ]
 webkit.org/b/195275 imported/w3c/web-platform-tests/css/css-text/white-space/text-space-collapse-preserve-breaks-001.xht [ ImageOnlyFailure ]
-webkit.org/b/214290 [ Debug ] imported/w3c/web-platform-tests/css/css-text/white-space/eol-spaces-bidi-001.html [ Skip ]
 webkit.org/b/214290 imported/w3c/web-platform-tests/css/css-text/white-space/seg-break-transformation-018.html [ ImageOnlyFailure ]
 webkit.org/b/214290 imported/w3c/web-platform-tests/css/css-text/white-space/seg-break-transformation-019.html [ ImageOnlyFailure ]
 webkit.org/b/214290 imported/w3c/web-platform-tests/css/css-text/white-space/textarea-pre-wrap-012.html [ ImageOnlyFailure ]

Source/WebCore/ChangeLog

@@ -1,3 +1,23 @@
+2022-01-21  Alan Bujtas  <zalan@apple.com>
+
+        [LFC][IFC] Inline boxes with collapsible content only should not be considered opaque bidi items
+        https://bugs.webkit.org/show_bug.cgi?id=235447
+
+        Reviewed by Antti Koivisto.
+
+        We don't normally submit inline boxes with content to ubidi re-ordering since their content drives the visual
+        position unless they are empty. While empty inline boxes do not usually produce visual artifacts (except ones with decoration)
+        they still need to be able to answer "bounding box" type of questions.
+
+        So in order to have geometry generated for inline boxes, they either
+        1, need to have some content so that while processing their content, we also compute their geometries
+        2, have to participate in ubidi's visual re-ordering so that they show up in the visual list (which is the input to the display box create function) 
+
+        This patch treats inline boxes with fully collapsible content empty so that they fall into group #2. 
+
+        * layout/formattingContexts/inline/InlineItemsBuilder.cpp:
+        (WebCore::Layout::InlineItemsBuilder::breakAndComputeBidiLevels):
+
 2022-01-21  Antti Koivisto  <antti@apple.com>
 
         WPT version of css/css-cascade/parsing/layer-import-parsing.html crashes with nullptr

Source/WebCore/layout/formattingContexts/inline/InlineItemsBuilder.cpp

@@ -428,7 +428,8 @@ void InlineItemsBuilder::breakAndComputeBidiLevels(InlineItems& inlineItems)
                 continue;
             }
             // Mark the inline box stack with "content yes", when we come across a content type of inline item.
-            inlineBoxContentFlagStack.fill(InlineBoxHasContent::Yes);
+            if (!inlineItem.isText() || !downcast<InlineTextItem>(inlineItem).isWhitespace() || TextUtil::shouldPreserveSpacesAndTabs(inlineItem.layoutBox()))
+                inlineBoxContentFlagStack.fill(InlineBoxHasContent::Yes);
         }
     };
     setBidiLevelForOpaqueInlineItems();