Changeset 295478 in webkit

Timestamp:

Jun 12, 2022 7:45:22 AM (2 years ago)

Author:

Alan Bujtas

Message:

Incorrect sizing of elements with visually hidden text inside
​https://bugs.webkit.org/show_bug.cgi?id=241459

Reviewed by Antti Koivisto.

This patch fixes the incorrect inline width computation when an inline box (e.g. <span>) with margin-inline-start (e.g. margin-left) is followed by an out-of-flow element.

<div id=container>some<span style="margin-left: 10px"><div style="position: absolute"></div>text</span></div>

In LineBreaker::nextLineBreak, while iterating through the content of [container], the margin-left of the inline box (span) is included twice; first for the out-of-flow box and second for the [text] content. This patch ensures that when we reach the [text] content, we check if we have already reserved the space for the inline box's margin (padding and border).
(While out-of-flow inline level boxes are not supposed to participate in inline layout, (in legacy line layout) in order to compute their static position we include them in line layout. A more involved fix would be to exclude all out-of-flow boxes from line layout and deal with their static positioning after completing the core line layout).

• LayoutTests/fast/block/shrink-to-fit-with-out-of-flow-and-inline-box-margin-expected.html: Added.
• LayoutTests/fast/block/shrink-to-fit-with-out-of-flow-and-inline-box-margin.html: Added.
• Source/WebCore/rendering/line/BreakingContext.h: Make sure when the out-of-flow box takes the margin, we don't add it again for the text content. Also, reset this flag for subsequent content.

(WebCore::inlineLogicalWidth):

Canonical link: ​https://commits.webkit.org/251483@main

Location:

trunk

Files:

• LayoutTests/fast/block/shrink-to-fit-with-out-of-flow-and-inline-box-margin-expected.html (added)
• LayoutTests/fast/block/shrink-to-fit-with-out-of-flow-and-inline-box-margin.html (added)
• Source/WebCore/rendering/line/BreakingContext.h (modified) (3 diffs)

trunk/Source/WebCore/rendering/line/BreakingContext.h

@@ -353 +353 @@
         positionedObjects.append(&box);
 
-    m_width.addUncommittedWidth(inlineLogicalWidth(box));
+    if (auto inlineBoxStartWidth = inlineLogicalWidth(box)) {
+        m_width.addUncommittedWidth(inlineBoxStartWidth);
+        m_appliedStartWidth = true;
+    }
     // Reset prior line break context characters.
     m_renderTextInfo.lineBreakIterator.resetPriorContext();
@@ -638 +641 @@
 inline bool BreakingContext::handleText(WordMeasurements& wordMeasurements, bool& hyphenated,  unsigned& consecutiveHyphenatedLines)
 {
-    if (!m_current.offset())
-        m_appliedStartWidth = false;
-
     auto& renderer = downcast<RenderText>(*m_current.renderer());
     bool isSVGText = renderer.isSVGInlineText();
@@ -1051 +1051 @@
         }
     }
+    m_appliedStartWidth = false;
     return false;
 }