[line-clamp] Disable overflow-wrap in a line with the ellipsis

andreubotella · chromium-wpt-export-bot · commit c740cb6add3c · 2025-06-18T12:14:35.000-07:00
Per the specification of `block-ellipsis` (one of the unexposed longhands that `line-clamp` is a shorthand for in the spec), the line-clamp ellipsis is placed after the last soft wrap opportunity that still allows the ellipsis to fit in the line, where soft wrap opportunities added by `overflow-wrap` are ignored. A previous CL, https://crrev.com/c/6394977, tried to implement this, and added a WPT test for it (`block-ellipsis-016.html`). However, it only tested and handled the case where the line would have overflown because it had `text-wrap: nowrap`, which was also handled specially with the line-clamp ellipsis. It did not handle cases where the line overflows because it has no soft wrap opportunities. This CL fixes that by not setting `break_anywhere_if_overflow_` when the line has a line-clamp ellipsis. Bug: 40336192 Change-Id: I657bc4b4b252c6b4f1fa39b57ff20d1446b5d0b9 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6654782 Commit-Queue: Andreu Botella <abotella@igalia.com> Reviewed-by: Koji Ishii <kojii@chromium.org> Cr-Commit-Position: refs/heads/main@{#1475729}
diff --git a/css/css-overflow/line-clamp/block-ellipsis-016.html b/css/css-overflow/line-clamp/block-ellipsis-016.html
@@ -3,19 +3,20 @@
 <title>CSS Overflow: soft wrap opportunities created by overflow-wrap are ignored for inserting block-ellipsis</title>
 <link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
 <link rel="help" href="https://drafts.csswg.org/css-overflow-4/#block-ellipsis">
-<link rel="match" href="reference/block-ellipsis-001-ref.html">
-<meta name="assert" content="The block-ellipsis is placed after the last soft wrap opportunity in the line box that fits the ellipsis. This happens even with text-wrap: nowrap, since that only prevents line wrapping, rather than removing wrap opportunities.">
+<link rel="match" href="reference/block-ellipsis-016-ref.html">
+<meta name="assert" content="The block-ellipsis is placed after the last soft wrap opportunity in the line box that fits the ellipsis. `overflow-wrap: anywhere`, however, does not count as creating soft wrap opportunities. Therefore, if a line with the ellipsis has no breakpoints that would prevent it from overflowing, it gets entirely displaced by the ellipsis.">
 <style>
 .clamp {
-  line-clamp: 2;
-  width: 63.1ch;
+  line-clamp: 3;
+  width: 20.1ch;
   border: 1px solid black;
   font-family: monospace;
-  white-space: pre;
   overflow-wrap: anywhere;
 }
 </style>
-<div class="clamp">This time, Mark, who had always been the center of attention in
-any social gathering, walked into the room uncharacteristically quietly, barely speaking as he settled into a chair.
-
-When asked, he said that he was fine, when he wasn't really fine.</div>
+<div class="clamp">
+  This time, Mark
+  walked in
+  uncharacteristically  <!-- the ellipsis would cause this line to overflow -->
+  quietly.
+</div>
diff --git a/css/css-overflow/line-clamp/reference/block-ellipsis-016-ref.html b/css/css-overflow/line-clamp/reference/block-ellipsis-016-ref.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  width: 20.1ch;
+  border: 1px solid black;
+  font-family: monospace;
+}
+</style>
+<div class="clamp">
+  This time, Mark
+  walked in <br>
+  …
+</div>
