WordPress · sirreal · Sep 12, 2024 · Sep 12, 2024 · Sep 13, 2024 · Sep 13, 2024
diff --git a/src/wp-includes/html-api/class-wp-html-processor.php b/src/wp-includes/html-api/class-wp-html-processor.php
@@ -279,51 +279,62 @@ class WP_HTML_Processor extends WP_HTML_Tag_Processor {
 	 * form is provided because a context element may have attributes that
 	 * impact the parse, such as with a SCRIPT tag and its `type` attribute.
 	 *
-	 * ## Current HTML Support
+	 * Example:
+	 *
+	 *     // Usually, snippets of HTML ought to be processed in the default `<body>` context:
+	 *     $processor = WP_HTML_Processor::create_fragment( '<p>Hi</p>' );
+	 *
+	 *     // Some fragments should be processed in the correct context like this SVG:
+	 *     $processor = WP_HTML_Processor::create_fragment( '<rect width="10" height="10" />', '<svg>' );
+	 *
+	 *     // This fragment with TD tags should be processed in a TR context:
+	 *     $processor = WP_HTML_Processor::create_fragment(
+	 *         '<td>1<td>2<td>3',
+	 *         '<table><tbody><tr>'
+	 *     );
 	 *
-	 *  - The only supported context is `<body>`, which is the default value.
-	 *  - The only supported document encoding is `UTF-8`, which is the default value.
+	 * In order to create a fragment processor at the correct location, the
+	 * provided fragment will be processed as part of a full HTML document.
+	 * The processor will search for the last opener tag in the document and
+	 * create a fragment processor at that location. The document will be
+	 * forced into "no-quirks" mode by including the HTML5 doctype.
+	 *
+	 * For advanced usage and precise control over the context element, use
+	 * `WP_HTML_Processor::create_full_processor()` and
+	 * `WP_HTML_Processor::create_fragment_at_current_node()`.
+	 *
+	 * UTF-8 is the only allowed encoding. If working with a document that
+	 * isn't UTF-8, first convert the document to UTF-8, then pass in the
+	 * converted HTML.
 	 *
 	 * @since 6.4.0
 	 * @since 6.6.0 Returns `static` instead of `self` so it can create subclass instances.
+	 * @since 6.8.0 Can create fragments with any context element.
 	 *
 	 * @param string $html     Input HTML fragment to process.
-	 * @param string $context  Context element for the fragment, must be default of `<body>`.
+	 * @param string $context  Context element for the fragment. Defaults to `<body>`.
 	 * @param string $encoding Text encoding of the document; must be default of 'UTF-8'.
 	 * @return static|null The created processor if successful, otherwise null.
 	 */
 	public static function create_fragment( $html, $context = '<body>', $encoding = 'UTF-8' ) {
-		if ( '<body>' !== $context || 'UTF-8' !== $encoding ) {
+		$context_processor = static::create_full_parser( "<!DOCTYPE html>{$context}", $encoding );
+		if ( null === $context_processor ) {
 			return null;
 		}
 
-		$processor                             = new static( $html, self::CONSTRUCTOR_UNLOCK_CODE );
-		$processor->state->insertion_mode      = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
-		$processor->state->encoding            = $encoding;
-		$processor->state->encoding_confidence = 'certain';
-
-		// @todo Create "fake" bookmarks for non-existent but implied nodes.
-		$processor->bookmarks['root-node']    = new WP_HTML_Span( 0, 0 );
-		$processor->bookmarks['context-node'] = new WP_HTML_Span( 0, 0 );
-
-		$root_node = new WP_HTML_Token(
-			'root-node',
-			'HTML',
-			false
-		);
-
-		$processor->state->stack_of_open_elements->push( $root_node );
-
-		$context_node = new WP_HTML_Token(
-			'context-node',
-			'BODY',
-			false
-		);
+		while ( $context_processor->next_tag() ) {
+			$context_processor->set_bookmark( 'final_node' );
+		}
 
-		$processor->context_node = $context_node;
-		$processor->breadcrumbs  = array( 'HTML', $context_node->node_name );
+		if (
+			! $context_processor->has_bookmark( 'final_node' ) ||
+			! $context_processor->seek( 'final_node' )
+		) {
+			_doing_it_wrong( __METHOD__, __( 'No valid context element was detected.' ), '6.8.0' );
+			return null;
+		}
 
-		return $processor;
+		return $context_processor->create_fragment_at_current_node( $html );
 	}
 
 	/**
@@ -333,9 +344,9 @@ public static function create_fragment( $html, $context = '<body>', $encoding =
 	 * entire HTML document from start to finish. Consider a fragment parser with
 	 * a context node of `<body>`.
 	 *
-	 * Since UTF-8 is the only currently-accepted charset, if working with a
-	 * document that isn't UTF-8, it's important to convert the document before
-	 * creating the processor: pass in the converted HTML.
+	 * UTF-8 is the only allowed encoding. If working with a document that
+	 * isn't UTF-8, first convert the document to UTF-8, then pass in the
+	 * converted HTML.
 	 *
 	 * @param string      $html                    Input HTML document to process.
 	 * @param string|null $known_definite_encoding Optional. If provided, specifies the charset used
@@ -459,35 +470,72 @@ function ( WP_HTML_Token $token ): void {
 	 *
 	 * @see https://html.spec.whatwg.org/multipage/parsing.html#html-fragment-parsing-algorithm
 	 *
+	 * @since 6.8.0
+	 *
 	 * @param string $html Input HTML fragment to process.
 	 * @return static|null The created processor if successful, otherwise null.
 	 */
 	public function create_fragment_at_current_node( string $html ) {
 		if ( $this->get_token_type() !== '#tag' || $this->is_tag_closer() ) {
+			_doing_it_wrong(
+				__METHOD__,
+				__( 'The context element must be a start tag.' ),
+				'6.8.0'
+			);
 			return null;
 		}
 
+		$tag_name  = $this->current_element->token->node_name;
 		$namespace = $this->current_element->token->namespace;
 
+		if ( 'html' === $namespace && self::is_void( $tag_name ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				sprintf(
+					// translators: %s: A tag name like INPUT or BR.
+					__( 'The context element cannot be a void element, found "%s".' ),
+					$tag_name
+				),
+				'6.8.0'
+			);
+			return null;
+		}
+
 		/*
 		 * Prevent creating fragments at nodes that require a special tokenizer state.
 		 * This is unsupported by the HTML Processor.
 		 */
 		if (
 			'html' === $namespace &&
-			in_array( $this->current_element->token->node_name, array( 'IFRAME', 'NOEMBED', 'NOFRAMES', 'SCRIPT', 'STYLE', 'TEXTAREA', 'TITLE', 'XMP', 'PLAINTEXT' ), true )
+			in_array( $tag_name, array( 'IFRAME', 'NOEMBED', 'NOFRAMES', 'SCRIPT', 'STYLE', 'TEXTAREA', 'TITLE', 'XMP', 'PLAINTEXT' ), true )
 		) {
+			_doing_it_wrong(
+				__METHOD__,
+				sprintf(
+					// translators: %s: A tag name like IFRAME or TEXTAREA.
+					__( 'The context element "%s" is not supported.' ),
+					$tag_name
+				),
+				'6.8.0'
+			);
 			return null;
 		}
 
-		$fragment_processor = static::create_fragment( $html );
-		if ( null === $fragment_processor ) {
-			return null;
-		}
+		$fragment_processor = new static( $html, self::CONSTRUCTOR_UNLOCK_CODE );
 
 		$fragment_processor->compat_mode = $this->compat_mode;
 
-		$fragment_processor->context_node                = clone $this->state->current_token;
+		// @todo Create "fake" bookmarks for non-existent but implied nodes.
+		$fragment_processor->bookmarks['root-node'] = new WP_HTML_Span( 0, 0 );
+		$root_node                                  = new WP_HTML_Token(
+			'root-node',
+			'HTML',
+			false
+		);
+		$fragment_processor->state->stack_of_open_elements->push( $root_node );
+
+		$fragment_processor->bookmarks['context-node']   = new WP_HTML_Span( 0, 0 );
+		$fragment_processor->context_node                = clone $this->current_element->token;
 		$fragment_processor->context_node->bookmark_name = 'context-node';
 		$fragment_processor->context_node->on_destroy    = null;
 

diff --git a/tests/phpunit/tests/html-api/wpHtmlProcessor.php b/tests/phpunit/tests/html-api/wpHtmlProcessor.php
@@ -1043,83 +1043,6 @@ public function test_ensure_next_token_method_extensibility( $html, $expected_to
 		$this->assertEquals( $expected_token_counts, $processor->token_seen_count, 'Snapshot: ' . var_export( $processor->token_seen_count, true ) );
 	}
 
-	/**
-	 * @ticket 62357
-	 */
-	public function test_create_fragment_at_current_node_in_foreign_content() {
-		$processor = WP_HTML_Processor::create_full_parser( '<svg>' );
-		$this->assertTrue( $processor->next_tag( 'SVG' ) );
-
-		$fragment = $processor->create_fragment_at_current_node( "\0preceded-by-nul-byte<rect /><circle></circle><foreignobject><div></div></foreignobject><g>" );
-
-		$this->assertSame( 'svg', $fragment->get_namespace() );
-		$this->assertTrue( $fragment->next_token() );
-
-		/*
-		 * In HTML parsing, a nul byte would be ignored.
-		 * In SVG it should be replaced with a replacement character.
-		 */
-		$this->assertSame( '#text', $fragment->get_token_type() );
-		$this->assertSame( "\u{FFFD}", $fragment->get_modifiable_text() );
-
-		$this->assertTrue( $fragment->next_tag( 'RECT' ) );
-		$this->assertSame( 'svg', $fragment->get_namespace() );
-
-		$this->assertTrue( $fragment->next_tag( 'CIRCLE' ) );
-		$this->assertSame( array( 'HTML', 'SVG', 'CIRCLE' ), $fragment->get_breadcrumbs() );
-		$this->assertTrue( $fragment->next_tag( 'foreignObject' ) );
-		$this->assertSame( 'svg', $fragment->get_namespace() );
-	}
-
-	/**
-	 * @ticket 62357
-	 */
-	public function test_create_fragment_at_current_node_in_foreign_content_integration_point() {
-		$processor = WP_HTML_Processor::create_full_parser( '<svg><foreignObject>' );
-		$this->assertTrue( $processor->next_tag( 'foreignObject' ) );
-
-		$fragment = $processor->create_fragment_at_current_node( "<image>\0not-preceded-by-nul-byte<rect />" );
-
-		// Nothing has been processed, the html namespace should be used for parsing as an integration point.
-		$this->assertSame( 'html', $fragment->get_namespace() );
-
-		// HTML parsing transforms IMAGE into IMG.
-		$this->assertTrue( $fragment->next_tag( 'IMG' ) );
-
-		$this->assertTrue( $fragment->next_token() );
-
-		// In HTML parsing, the nul byte is ignored and the text is reached.
-		$this->assertSame( '#text', $fragment->get_token_type() );
-		$this->assertSame( 'not-preceded-by-nul-byte', $fragment->get_modifiable_text() );
-
-		/*
-		 * svg:foreignObject is an HTML integration point, so the processor should be in the HTML namespace.
-		 * RECT is an HTML element here, meaning it may have the self-closing flag but does not self-close.
-		 */
-		$this->assertTrue( $fragment->next_tag( 'RECT' ) );
-		$this->assertSame( array( 'HTML', 'FOREIGNOBJECT', 'RECT' ), $fragment->get_breadcrumbs() );
-		$this->assertSame( 'html', $fragment->get_namespace() );
-		$this->assertTrue( $fragment->has_self_closing_flag() );
-		$this->assertTrue( $fragment->expects_closer() );
-	}
-
-	/**
-	 * @ticket 62357
-	 */
-	public function test_prevent_fragment_creation_on_closers() {
-		$processor = WP_HTML_Processor::create_full_parser( '<p></p>' );
-		$processor->next_tag( 'P' );
-		$processor->next_tag(
-			array(
-				'tag_name'    => 'P',
-				'tag_closers' => 'visit',
-			)
-		);
-		$this->assertSame( 'P', $processor->get_tag() );
-		$this->assertTrue( $processor->is_tag_closer() );
-		$this->assertNull( $processor->create_fragment_at_current_node( '<i>fragment HTML</i>' ) );
-	}
-
 	/**
 	 * Ensure that lowercased tag_name query matches tags case-insensitively.
 	 *