ignore invalid selectors

lib/single-file/css-rules-matcher.js

@@ -297,7 +297,12 @@ this.RulesMatcher = this.RulesMatcher || (() => {
 	}
 
 	function getFilteredSelector(selector) {
-		const selectors = cssWhat.parse(selector);
+		let selectors;
+		try {
+			selectors = cssWhat.parse(selector);
+		} catch (error) {
+			return selector;
+		}
 		return cssWhat.stringify(selectors.map(selector => filterPseudoClasses(selector)));
 
 		function filterPseudoClasses(selector, negatedData) {