Add failing test for <!----->

Author: sirreal

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

@@ -581,6 +581,26 @@ 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.
 	 *