Lay a table cell's one text inline, so a copied row stays on one line

CHANGELOG.md

@@ -6,6 +6,14 @@ and `MarkupString.Pueblo`. The packages share one version and are released toget
 The format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and the project
 follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 2.24.1 — Unreleased
+
+### Fixed
+
+- **A copied table keeps its rows**: a cell's text is no longer a block of its own, which a browser copied
+  as a line per cell. A cell that holds one text is laid out inline, so a copied row is its cells with tabs
+  between them.
+
 ## 2.24.0 — Unreleased
 
 ### Added

MarkupString.Html/LayoutCss.cs

@@ -101,6 +101,9 @@ public static class LayoutCss
 		".ms-table { border-collapse: collapse; }\n" +
 		".ms-table.ms-fill { width: 100%; }\n" +
 		".ms-table th, .ms-table td { padding: 0 1ch; vertical-align: top; text-align: left; }\n" +
+		// A block inside a cell is copied as a line of its own, so a cell of one text is laid out inline: a copied
+		// row is its cells with tabs between, as a table with bare text in its cells copies.
+		".ms-table :is(th, td) > .ms-text:only-child { display: inline-block; width: 100%; }\n" +
 		".ms-table th { border-bottom: 1px solid var(--ms-header-rule, var(--ms-header-rule-default, currentColor)); color: var(--ms-heading, var(--ms-heading-default, inherit)); }\n" +
 		".ms-table.ms-striped > tbody > tr:nth-child(even) { background: var(--ms-stripe, var(--ms-stripe-default, rgba(127, 127, 127, 0.12))); }\n" +
 		".ms-table .ms-nowrap, .ms-table .ms-nowrap .ms-text { white-space: pre; overflow-wrap: normal; }\n" +

MarkupString.Tests/Layout/WidgetLayoutTests.cs

@@ -187,6 +187,13 @@ public async Task Table_InHtml_KeepsAColumnThatDoesNotWrapOnOneLine()
 		await Assert.That(LayoutCss.Fixed).Contains(".ms-table .ms-nowrap, .ms-table .ms-nowrap .ms-text { white-space: pre; overflow-wrap: normal; }");
 	}
 
+	[Test]
+	public async Task Table_InHtml_LaysACellsOneTextInline()
+	{
+		// A browser copies a block as a line of its own: a cell's only text inline keeps a copied row on one line.
+		await Assert.That(LayoutCss.Fixed).Contains(".ms-table :is(th, td) > .ms-text:only-child { display: inline-block; width: 100%; }");
+	}
+
 	[Test]
 	public async Task Table_InHtml_NoWrapWithoutPriority_HasOnlyItsClass()
 	{