From 5f9ca781d15092251a58a0723cce81c48bff7f59 Mon Sep 17 00:00:00 2001
From: Stegmujo <johannesst@gmx.de>
Date: Thu, 16 Mar 2023 14:47:26 +0000
Subject: [PATCH] Fix spaces not rendering if within mtext

* MMLFullCoverageTest case: 260

Bug: T327391
Change-Id: Ifd858216b646efd53c401ac9bcddfc7fb1c1a933
---
 src/TexVC/Nodes/Box.php                    | 14 +++++++++++++-
 tests/phpunit/unit/TexVC/Nodes/BoxTest.php | 10 ++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/TexVC/Nodes/Box.php b/src/TexVC/Nodes/Box.php
index 3c4c95a82..01e5f673c 100644
--- a/src/TexVC/Nodes/Box.php
+++ b/src/TexVC/Nodes/Box.php
@@ -45,8 +45,20 @@ class Box extends TexNode {
 	public function renderMML( $arguments = [], $state = [] ) {
 		$mrow = new MMLmrow();
 		$mtext = new MMLmtext();
+		$arg = $this->getArg();
+
+		if ( strlen( $arg ) >= 1 ) {
+			// Replace trailing and leading spaces with special space sign
+			if ( substr( $arg, -1, 1 ) === " " ) {
+				$arg = rtrim( $arg, " " ) . "&#xA0;";
+			}
+			if ( substr( $arg, 0, 1 ) == " " ) {
+				$arg = "&#xA0;" . ltrim( $arg, " " );
+			}
+		}
+
 		return $mrow->encapsulateRaw(
-			$mtext->encapsulateRaw( $this->getArg() )
+			$mtext->encapsulateRaw( $arg )
 		);
 	}
 
diff --git a/tests/phpunit/unit/TexVC/Nodes/BoxTest.php b/tests/phpunit/unit/TexVC/Nodes/BoxTest.php
index 152b09c1c..9a7f1beb6 100644
--- a/tests/phpunit/unit/TexVC/Nodes/BoxTest.php
+++ b/tests/phpunit/unit/TexVC/Nodes/BoxTest.php
@@ -57,4 +57,14 @@ class BoxTest extends MediaWikiUnitTestCase {
 		$box = new Box( '\\hbox', 'a' );
 		$this->assertStringContainsString( '</mtext>', $box->renderMML(), 'Render MathML as text.' );
 	}
+
+	public function testTrailingSpaceBoxMML() {
+		$box = new Box( '\\hbox', 'a ' );
+		$this->assertStringContainsString( '&#xA0;', $box->renderMML(), 'Should have trailing rendered space' );
+	}
+
+	public function testPrecedingSpaceBoxMML() {
+		$box = new Box( '\\hbox', ' a' );
+		$this->assertStringContainsString( '&#xA0;', $box->renderMML(), 'Should have preceding rendered space' );
+	}
 }