From 1aac0a2992e3bbec0436c5e01e00bfc4fef3ccc2 Mon Sep 17 00:00:00 2001
From: Brad Jorsch <bjorsch@wikimedia.org>
Date: Thu, 27 Apr 2017 12:58:17 -0400
Subject: [PATCH] Wrap parser output in <div class="mw-parser-output">

This will allow CSS to target just the parser output, without also
accidentally targeting the edit form, diff tables, and so on.

Bug: T37247
Change-Id: If4eb5bf71f94fa366ec4eddb6964e8f4df6b824a
Depends-On: I330c6aa4aaee045614b1801ed34bc9e03be69650
Depends-On: I52a518fa44e017841fe78474012cd69823e0a41d
---
 RELEASE-NOTES-1.30                            |  8 ++++--
 includes/api/ApiParse.php                     |  4 +++
 includes/api/i18n/en.json                     |  1 +
 includes/api/i18n/qqq.json                    |  1 +
 includes/cache/MessageCache.php               |  6 ++++
 includes/parser/Parser.php                    |  8 ++++++
 includes/parser/ParserOptions.php             | 28 +++++++++++++++++++
 tests/parser/ParserTestRunner.php             |  4 +++
 tests/parser/parserTests.txt                  |  1 +
 tests/phpunit/includes/ExtraParserTest.php    |  2 ++
 .../includes/content/WikitextContentTest.php  |  2 +-
 tests/phpunit/includes/page/WikiPageTest.php  |  8 ++++--
 .../phpunit/includes/parser/TagHooksTest.php  | 23 +++++++++------
 13 files changed, 83 insertions(+), 13 deletions(-)

diff --git a/RELEASE-NOTES-1.30 b/RELEASE-NOTES-1.30
index cdf8ba4421..1351c00f38 100644
--- a/RELEASE-NOTES-1.30
+++ b/RELEASE-NOTES-1.30
@@ -14,7 +14,9 @@ production.
   documentation of $wgShellLocale for details.
 
 === New features in 1.30 ===
-* …
+* (T37247) Output from Parser::parse() will now be wrapped in a div with
+  class="mw-parser-output" by default. This may be changed or disabled using
+  ParserOptions::setWrapOutputClass().
 
 === External library changes in 1.30 ===
 
@@ -31,7 +33,9 @@ production.
 * …
 
 === Action API changes in 1.30 ===
-* …
+* (T37247) action=parse output will be wrapped in a div with
+  class="mw-parser-output" by default. This may be changed or disabled using
+  the new 'wrapoutputclass' parameter.
 
 === Action API internal changes in 1.30 ===
 * …
diff --git a/includes/api/ApiParse.php b/includes/api/ApiParse.php
index d6489688e6..7d22d9c470 100644
--- a/includes/api/ApiParse.php
+++ b/includes/api/ApiParse.php
@@ -478,6 +478,9 @@ class ApiParse extends ApiBase {
 		if ( $params['disabletidy'] ) {
 			$popts->setTidy( false );
 		}
+		$popts->setWrapOutputClass(
+			$params['wrapoutputclass'] === '' ? false : $params['wrapoutputclass']
+		);
 
 		$reset = null;
 		$suppressCache = false;
@@ -788,6 +791,7 @@ class ApiParse extends ApiBase {
 					'parsetree' => [ 'apihelp-parse-paramvalue-prop-parsetree', CONTENT_MODEL_WIKITEXT ],
 				],
 			],
+			'wrapoutputclass' => 'mw-parser-output',
 			'pst' => false,
 			'onlypst' => false,
 			'effectivelanglinks' => false,
diff --git a/includes/api/i18n/en.json b/includes/api/i18n/en.json
index 7a04cafafb..387e4b6d7a 100644
--- a/includes/api/i18n/en.json
+++ b/includes/api/i18n/en.json
@@ -349,6 +349,7 @@
 	"apihelp-parse-paramvalue-prop-limitreporthtml": "Gives the HTML version of the limit report. Gives no data, when <var>$1disablelimitreport</var> is set.",
 	"apihelp-parse-paramvalue-prop-parsetree": "The XML parse tree of revision content (requires content model <code>$1</code>)",
 	"apihelp-parse-paramvalue-prop-parsewarnings": "Gives the warnings that occurred while parsing content.",
+	"apihelp-parse-param-wrapoutputclass": "CSS class to use to wrap the parser output.",
 	"apihelp-parse-param-pst": "Do a pre-save transform on the input before parsing it. Only valid when used with text.",
 	"apihelp-parse-param-onlypst": "Do a pre-save transform (PST) on the input, but don't parse it. Returns the same wikitext, after a PST has been applied. Only valid when used with <var>$1text</var>.",
 	"apihelp-parse-param-effectivelanglinks": "Includes language links supplied by extensions (for use with <kbd>$1prop=langlinks</kbd>).",
diff --git a/includes/api/i18n/qqq.json b/includes/api/i18n/qqq.json
index 6e70653463..81adeec437 100644
--- a/includes/api/i18n/qqq.json
+++ b/includes/api/i18n/qqq.json
@@ -331,6 +331,7 @@
 	"apihelp-parse-paramvalue-prop-limitreporthtml": "{{doc-apihelp-paramvalue|parse|prop|limitreporthtml}}",
 	"apihelp-parse-paramvalue-prop-parsetree": "{{doc-apihelp-paramvalue|parse|prop|parsetree|params=* $1 - Value of the constant CONTENT_MODEL_WIKITEXT|paramstart=2}}",
 	"apihelp-parse-paramvalue-prop-parsewarnings": "{{doc-apihelp-paramvalue|parse|prop|parsewarnings}}",
+	"apihelp-parse-param-wrapoutputclass": "{{doc-apihelp-param|parse|wrapoutputclass}}",
 	"apihelp-parse-param-pst": "{{doc-apihelp-param|parse|pst}}",
 	"apihelp-parse-param-onlypst": "{{doc-apihelp-param|parse|onlypst}}",
 	"apihelp-parse-param-effectivelanglinks": "{{doc-apihelp-param|parse|effectivelanglinks}}",
diff --git a/includes/cache/MessageCache.php b/includes/cache/MessageCache.php
index 355aff40ed..5caa7d5f35 100644
--- a/includes/cache/MessageCache.php
+++ b/includes/cache/MessageCache.php
@@ -193,6 +193,7 @@ class MessageCache {
 				$po = ParserOptions::newFromAnon();
 				$po->setEditSection( false );
 				$po->setAllowUnsafeRawHtml( false );
+				$po->setWrapOutputClass( false );
 				return $po;
 			}
 
@@ -202,6 +203,11 @@ class MessageCache {
 			// from malicious sources. As a precaution, disable
 			// the <html> parser tag when parsing messages.
 			$this->mParserOptions->setAllowUnsafeRawHtml( false );
+			// Wrapping messages in an extra <div> is probably not expected. If
+			// they're outside the content area they probably shouldn't be
+			// targeted by CSS that's targeting the parser output, and if
+			// they're inside they already are from the outer div.
+			$this->mParserOptions->setWrapOutputClass( false );
 		}
 
 		return $this->mParserOptions;
diff --git a/includes/parser/Parser.php b/includes/parser/Parser.php
index 5b1e86d252..ecee0e22d3 100644
--- a/includes/parser/Parser.php
+++ b/includes/parser/Parser.php
@@ -589,6 +589,14 @@ class Parser {
 					$this->mTitle->getPrefixedDBkey() );
 			}
 		}
+
+		# Wrap non-interface parser output in a <div> so it can be targeted
+		# with CSS (T37247)
+		$class = $this->mOptions->getWrapOutputClass();
+		if ( $class !== false && !$this->mOptions->getInterfaceMessage() ) {
+			$text = Html::rawElement( 'div', [ 'class' => $class ], $text );
+		}
+
 		$this->mOutput->setText( $text );
 
 		$this->mRevisionId = $oldRevisionId;
diff --git a/includes/parser/ParserOptions.php b/includes/parser/ParserOptions.php
index 2cdd8c7075..d4d104231d 100644
--- a/includes/parser/ParserOptions.php
+++ b/includes/parser/ParserOptions.php
@@ -258,6 +258,12 @@ class ParserOptions {
 	 */
 	private $allowUnsafeRawHtml = true;
 
+	/**
+	 * CSS class to use to wrap output from Parser::parse().
+	 * @var string|false
+	 */
+	private $wrapOutputClass = 'mw-parser-output';
+
 	public function getInterwikiMagic() {
 		return $this->mInterwikiMagic;
 	}
@@ -481,6 +487,15 @@ class ParserOptions {
 		return $this->allowUnsafeRawHtml;
 	}
 
+	/**
+	 * Class to use to wrap output from Parser::parse()
+	 * @since 1.30
+	 * @return string|bool
+	 */
+	public function getWrapOutputClass() {
+		return $this->wrapOutputClass;
+	}
+
 	public function setInterwikiMagic( $x ) {
 		return wfSetVar( $this->mInterwikiMagic, $x );
 	}
@@ -629,6 +644,19 @@ class ParserOptions {
 		return wfSetVar( $this->allowUnsafeRawHtml, $x );
 	}
 
+	/**
+	 * CSS class to use to wrap output from Parser::parse()
+	 * @since 1.30
+	 * @param string|bool $className Set false to disable wrapping.
+	 * @return string|bool Current value
+	 */
+	public function setWrapOutputClass( $className ) {
+		if ( $className === true ) { // DWIM, they probably want the default class name
+			$className = 'mw-parser-output';
+		}
+		return wfSetVar( $this->wrapOutputClass, $className );
+	}
+
 	/**
 	 * Set the redirect target.
 	 *
diff --git a/tests/parser/ParserTestRunner.php b/tests/parser/ParserTestRunner.php
index f100411f25..f44b0d5e26 100644
--- a/tests/parser/ParserTestRunner.php
+++ b/tests/parser/ParserTestRunner.php
@@ -747,6 +747,10 @@ class ParserTestRunner {
 		$user = $context->getUser();
 		$options = ParserOptions::newFromContext( $context );
 
+		if ( !isset( $opts['wrap'] ) ) {
+			$options->setWrapOutputClass( false );
+		}
+
 		if ( isset( $opts['tidy'] ) ) {
 			if ( !$this->tidySupport->isEnabled() ) {
 				$this->recorder->skipped( $test, 'tidy extension is not installed' );
diff --git a/tests/parser/parserTests.txt b/tests/parser/parserTests.txt
index e12c136d91..6477356c8a 100644
--- a/tests/parser/parserTests.txt
+++ b/tests/parser/parserTests.txt
@@ -32,6 +32,7 @@
 # local         format section links in edit comment text as local links
 # notoc         disable table of contents
 # thumbsize=NNN set the default thumb size to NNNpx for this test
+# wrap          include the normal wrapper <div class="mw-parser-output"> (since 1.30)
 #
 # You can also set the following parser properties via test options:
 #  wgEnableUploads, wgAllowExternalImages, wgMaxTocLevel,
diff --git a/tests/phpunit/includes/ExtraParserTest.php b/tests/phpunit/includes/ExtraParserTest.php
index 4e95a30e09..a4e3bb9493 100644
--- a/tests/phpunit/includes/ExtraParserTest.php
+++ b/tests/phpunit/includes/ExtraParserTest.php
@@ -26,6 +26,7 @@ class ExtraParserTest extends MediaWikiTestCase {
 		// FIXME: This test should pass without setting global content language
 		$this->options = ParserOptions::newFromUserAndLang( new User, $contLang );
 		$this->options->setTemplateCallback( [ __CLASS__, 'statelessFetchTemplate' ] );
+		$this->options->setWrapOutputClass( false );
 		$this->parser = new Parser;
 
 		MagicWord::clearCache();
@@ -40,6 +41,7 @@ class ExtraParserTest extends MediaWikiTestCase {
 
 		$title = Title::newFromText( 'Unit test' );
 		$options = ParserOptions::newFromUser( new User() );
+		$options->setWrapOutputClass( false );
 		$this->assertEquals( "<p>$longLine</p>",
 			$this->parser->parse( $longLine, $title, $options )->getText() );
 	}
diff --git a/tests/phpunit/includes/content/WikitextContentTest.php b/tests/phpunit/includes/content/WikitextContentTest.php
index 4c69d871b9..b9ce997f23 100644
--- a/tests/phpunit/includes/content/WikitextContentTest.php
+++ b/tests/phpunit/includes/content/WikitextContentTest.php
@@ -29,7 +29,7 @@ more stuff
 				"WikitextContentTest_testGetParserOutput",
 				CONTENT_MODEL_WIKITEXT,
 				"hello ''world''\n",
-				"<p>hello <i>world</i>\n</p>"
+				"<div class=\"mw-parser-output\"><p>hello <i>world</i>\n</p>\n\n\n</div>"
 			],
 			// TODO: more...?
 		];
diff --git a/tests/phpunit/includes/page/WikiPageTest.php b/tests/phpunit/includes/page/WikiPageTest.php
index 6b911bf3a6..556a34813c 100644
--- a/tests/phpunit/includes/page/WikiPageTest.php
+++ b/tests/phpunit/includes/page/WikiPageTest.php
@@ -549,7 +549,11 @@ class WikiPageTest extends MediaWikiLangTestCase {
 
 	public static function provideGetParserOutput() {
 		return [
-			[ CONTENT_MODEL_WIKITEXT, "hello ''world''\n", "<p>hello <i>world</i></p>" ],
+			[
+				CONTENT_MODEL_WIKITEXT,
+				"hello ''world''\n",
+				"<div class=\"mw-parser-output\"><p>hello <i>world</i></p></div>"
+			],
 			// @todo more...?
 		];
 	}
@@ -566,7 +570,7 @@ class WikiPageTest extends MediaWikiLangTestCase {
 		$text = $po->getText();
 
 		$text = trim( preg_replace( '/<!--.*?-->/sm', '', $text ) ); # strip injected comments
-		$text = preg_replace( '!\s*(</p>)!sm', '\1', $text ); # don't let tidy confuse us
+		$text = preg_replace( '!\s*(</p>|</div>)!sm', '\1', $text ); # don't let tidy confuse us
 
 		$this->assertEquals( $expectedHtml, $text );
 
diff --git a/tests/phpunit/includes/parser/TagHooksTest.php b/tests/phpunit/includes/parser/TagHooksTest.php
index 12936ee21d..06fe272b29 100644
--- a/tests/phpunit/includes/parser/TagHooksTest.php
+++ b/tests/phpunit/includes/parser/TagHooksTest.php
@@ -43,18 +43,25 @@ class TagHookTest extends MediaWikiTestCase {
 		return [ [ "foo<bar" ], [ "foo>bar" ], [ "foo\nbar" ], [ "foo\rbar" ] ];
 	}
 
+	private function getParserOptions() {
+		global $wgContLang;
+		$popt = ParserOptions::newFromUserAndLang( new User, $wgContLang );
+		$popt->setWrapOutputClass( false );
+		return $popt;
+	}
+
 	/**
 	 * @dataProvider provideValidNames
 	 */
 	public function testTagHooks( $tag ) {
-		global $wgParserConf, $wgContLang;
+		global $wgParserConf;
 		$parser = new Parser( $wgParserConf );
 
 		$parser->setHook( $tag, [ $this, 'tagCallback' ] );
 		$parserOutput = $parser->parse(
 			"Foo<$tag>Bar</$tag>Baz",
 			Title::newFromText( 'Test' ),
-			ParserOptions::newFromUserAndLang( new User, $wgContLang )
+			$this->getParserOptions()
 		);
 		$this->assertEquals( "<p>FooOneBaz\n</p>", $parserOutput->getText() );
 
@@ -66,14 +73,14 @@ class TagHookTest extends MediaWikiTestCase {
 	 * @expectedException MWException
 	 */
 	public function testBadTagHooks( $tag ) {
-		global $wgParserConf, $wgContLang;
+		global $wgParserConf;
 		$parser = new Parser( $wgParserConf );
 
 		$parser->setHook( $tag, [ $this, 'tagCallback' ] );
 		$parser->parse(
 			"Foo<$tag>Bar</$tag>Baz",
 			Title::newFromText( 'Test' ),
-			ParserOptions::newFromUserAndLang( new User, $wgContLang )
+			$this->getParserOptions()
 		);
 		$this->fail( 'Exception not thrown.' );
 	}
@@ -82,14 +89,14 @@ class TagHookTest extends MediaWikiTestCase {
 	 * @dataProvider provideValidNames
 	 */
 	public function testFunctionTagHooks( $tag ) {
-		global $wgParserConf, $wgContLang;
+		global $wgParserConf;
 		$parser = new Parser( $wgParserConf );
 
 		$parser->setFunctionTagHook( $tag, [ $this, 'functionTagCallback' ], 0 );
 		$parserOutput = $parser->parse(
 			"Foo<$tag>Bar</$tag>Baz",
 			Title::newFromText( 'Test' ),
-			ParserOptions::newFromUserAndLang( new User, $wgContLang )
+			$this->getParserOptions()
 		);
 		$this->assertEquals( "<p>FooOneBaz\n</p>", $parserOutput->getText() );
 
@@ -101,7 +108,7 @@ class TagHookTest extends MediaWikiTestCase {
 	 * @expectedException MWException
 	 */
 	public function testBadFunctionTagHooks( $tag ) {
-		global $wgParserConf, $wgContLang;
+		global $wgParserConf;
 		$parser = new Parser( $wgParserConf );
 
 		$parser->setFunctionTagHook(
@@ -112,7 +119,7 @@ class TagHookTest extends MediaWikiTestCase {
 		$parser->parse(
 			"Foo<$tag>Bar</$tag>Baz",
 			Title::newFromText( 'Test' ),
-			ParserOptions::newFromUserAndLang( new User, $wgContLang )
+			$this->getParserOptions()
 		);
 		$this->fail( 'Exception not thrown.' );
 	}
-- 
2.20.1