Fix span-of-dashes comment modifiable text

Author: dmsnell

src/wp-includes/html-api/class-wp-html-tag-processor.php

@@ -1603,8 +1603,13 @@ private function parse_next_tag() {
 						 */
 						$this->parser_state         = self::STATE_COMMENT;
 						$this->token_length         = $closer_at + $span_of_dashes + 1 - $this->token_starts_at;
-						$this->text_starts_at       = $this->token_starts_at + 4;
-						$this->text_length          = max( 0, $closer_at - $this->text_starts_at );
+
+						// Only provide modifiable text if the token is long enough to contain it.
+						if ( $span_of_dashes >= 2 ) {
+							$this->text_starts_at = $this->token_starts_at + 4;
+							$this->text_length    = $span_of_dashes - 2;
+						}
+
 						$this->bytes_already_parsed = $closer_at + $span_of_dashes + 1;
 						return true;
 					}

tests/phpunit/tests/html-api/wpHtmlTagProcessor-token-scanning.php

@@ -531,11 +531,13 @@ public function test_basic_assertion_common_comments( $html, $text ) {
 	 */
 	public function data_common_comments() {
 		return array(
-			'Shortest comment'       => array( '<!-->', '' ),
-			'Short comment'          => array( '<!--->', '' ),
-			'PI node without target' => array( '<? missing?>', ' missing?' ),
-			'Invalid PI node'        => array( '<?/missing/>', '/missing/' ),
-			'Invalid ! directive'    => array( '<!something else>', 'something else' ),
+			'Shortest comment'        => array( '<!-->', '' ),
+			'Short comment'           => array( '<!--->', '' ),
+			'Short comment w/o text'  => array( '<!---->', '' ),
+			'Short comment with text' => array( '<!----->', '-' ),
+			'PI node without target'  => array( '<? missing?>', ' missing?' ),
+			'Invalid PI node'         => array( '<?/missing/>', '/missing/' ),
+			'Invalid ! directive'     => array( '<!something else>', 'something else' ),
 		);
 	}
 
@@ -581,26 +583,6 @@ public function test_basic_assertion_html_comment() {
 		);
 	}
 
-	/**
-	 * Ensures that <!-----> HTML comment is properly parsed.
-	 *
-	 * @ticket 60170
-	 *
-	 * @since 6.5.0
-	 *
-	 * @covers WP_HTML_Tag_Processor::next_token
-	 */
-	public function test_html_comment_single_dash() {
-		$processor = WP_HTML_Processor::create_fragment( '<!----->' );
-		$processor->next_token();
-
-		$this->assertSame(
-			'-',
-			$processor->get_modifiable_text(),
-			'Found incorrect modifiable text.'
-		);
-	}
-
 	/**
 	 * Ensures that normative DOCTYPE elements are properly parsed.
 	 *