text-indent not working on contenteditable elements in Safari 26.2

alanbaradlay · alanbaradlay · commit 7594f8949c63 · 2026-02-16T07:59:06.000-08:00
https://bugs.webkit.org/show_bug.cgi?id=307125 <rdar://problem/170280101> Reviewed by Antti Koivisto. 1. text-indent relies on 'isFirstFormattedLineCandidate' 2. isFirstFormattedLineCandidate checks if there's a valid previousLine (std::optional<PreviousLine> When partial layout starts from the first line (damage is either on the first or the second line), we should just have std::null_opt as PreviousLine. Test: fast/text/partial-layout-with-text-indent.html * LayoutTests/fast/text/partial-layout-with-text-indent-expected.html: Added. * LayoutTests/fast/text/partial-layout-with-text-indent.html: Added. * Source/WebCore/layout/formattingContexts/inline/InlineFormattingContext.cpp: (WebCore::Layout::InlineFormattingContext::layout): Canonical link: https://commits.webkit.org/307646@main
diff --git a/LayoutTests/fast/text/partial-layout-with-text-indent-expected.html b/LayoutTests/fast/text/partial-layout-with-text-indent-expected.html
@@ -0,0 +1,10 @@
+<style>
+div {
+  text-indent: 20px;
+  border: 1px solid green;
+  width: 200px;
+  height: 400px;
+  font-family: Ahem;
+}
+</style>
+<div id=change_this class="editable" contenteditable="true"> some text</div>
diff --git a/LayoutTests/fast/text/partial-layout-with-text-indent.html b/LayoutTests/fast/text/partial-layout-with-text-indent.html
@@ -0,0 +1,14 @@
+<style>
+div {
+  text-indent: 20px;
+  border: 1px solid green;
+  width: 200px;
+  height: 400px;
+  font-family: Ahem;
+}
+</style>
+<div id=change_this class="editable" contenteditable="true"> some </div>
+<script>
+document.body.offsetHeight;
+change_this.appendChild(document.createTextNode("text"));
+</script>
diff --git a/Source/WebCore/layout/formattingContexts/inline/InlineFormattingContext.cpp b/Source/WebCore/layout/formattingContexts/inline/InlineFormattingContext.cpp
@@ -158,6 +158,8 @@ std::unique_ptr<InlineLayoutResult> InlineFormattingContext::layout(const Constr
             ASSERT_NOT_REACHED();
             return { };
         }
+        if (!lineDamage->layoutStartPosition()->lineIndex)
+            return { };
         auto lastLineIndex = lineDamage->layoutStartPosition()->lineIndex - 1;
         // FIXME: We should be able to extract the last line information and provide it to layout as "previous line" (ends in line break and inline direction).
         return PreviousLine { lastLineIndex, { }, { }, { }, { } };

Original file line number	Diff line number	Diff line change
`@@ -158,6 +158,8 @@ std::unique_ptr<InlineLayoutResult> InlineFormattingContext::layout(const Constr`
`158`	`158`	`ASSERT_NOT_REACHED();`
`159`	`159`	`return { };`
`160`	`160`	`}`
	`161`	`+ if (!lineDamage->layoutStartPosition()->lineIndex)`
	`162`	`+ return { };`
`161`	`163`	`auto lastLineIndex = lineDamage->layoutStartPosition()->lineIndex - 1;`
`162`	`164`	`// FIXME: We should be able to extract the last line information and provide it to layout as "previous line" (ends in line break and inline direction).`
`163`	`165`	`return PreviousLine { lastLineIndex, { }, { }, { }, { } };`