From 80d8af47f7dc64d6615f813dc3d69230230d0580 Mon Sep 17 00:00:00 2001
From: daniel <dkinzler@wikimedia.org>
Date: Thu, 3 Nov 2022 16:40:59 +0100
Subject: [PATCH] Produce HTML for invalid JSON

implementations of ContentHandler::fillParserOutput MUST set HTML if
$cpoParams->getGenerateHtml() returns true.

Bug: T321319
Change-Id: Ibd43f7420e949666649752dce7072dc35bc1f440
---
 includes/content/JsonContentHandler.php                | 10 ++++++++--
 .../content/JsonContentHandlerIntegrationTest.php      | 10 +++++++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/includes/content/JsonContentHandler.php b/includes/content/JsonContentHandler.php
index bfad6851157..4e166a3c76e 100644
--- a/includes/content/JsonContentHandler.php
+++ b/includes/content/JsonContentHandler.php
@@ -129,8 +129,14 @@ class JsonContentHandler extends CodeContentHandler {
 		'@phan-var JsonContent $content';
 		// FIXME: WikiPage::doUserEditContent generates parser output before validation.
 		// As such, native data may be invalid (though output is discarded later in that case).
-		if ( $cpoParams->getGenerateHtml() && $content->isValid() ) {
-			$parserOutput->setText( $content->rootValueTable( $content->getData()->getValue() ) );
+		if ( $cpoParams->getGenerateHtml() ) {
+			if ( $content->isValid() ) {
+				$parserOutput->setText( $content->rootValueTable( $content->getData()->getValue() ) );
+			} else {
+				$error = wfMessage( 'invalid-json-data' )->parse();
+				$parserOutput->setText( $error );
+			}
+
 			$parserOutput->addModuleStyles( [ 'mediawiki.content.json' ] );
 		} else {
 			$parserOutput->setText( null );
diff --git a/tests/phpunit/includes/content/JsonContentHandlerIntegrationTest.php b/tests/phpunit/includes/content/JsonContentHandlerIntegrationTest.php
index 94506c76881..9f47a6a2728 100644
--- a/tests/phpunit/includes/content/JsonContentHandlerIntegrationTest.php
+++ b/tests/phpunit/includes/content/JsonContentHandlerIntegrationTest.php
@@ -48,6 +48,10 @@ class JsonContentHandlerIntegrationTest extends MediaWikiLangTestCase {
 				'&lt;script>alert("evil!")&lt;/script>"' .
 				'</td></tr></tbody></table>',
 			],
+			[
+				'{ broken JSON ]',
+				'Invalid JSON: $1',
+			],
 		];
 	}
 
@@ -56,7 +60,11 @@ class JsonContentHandlerIntegrationTest extends MediaWikiLangTestCase {
 	 * @covers JsonContentHandler::fillParserOutput
 	 */
 	public function testFillParserOutput( $data, $expected ) {
-		$content = new JsonContent( FormatJson::encode( $data ) );
+		if ( !is_string( $data ) ) {
+			$data = FormatJson::encode( $data );
+		}
+
+		$content = new JsonContent( $data );
 		$contentRenderer = $this->getServiceContainer()->getContentRenderer();
 		$parserOutput = $contentRenderer->getParserOutput(
 			$content,