Detect invalid calc definitions like 'calc ('

Author: raxbg

lib/Sabberworm/CSS/Value/CalcFunction.php

@@ -12,10 +12,13 @@ class CalcFunction extends CSSFunction {
 	public static function parse(ParserState $oParserState) {
 		$aOperators = array('+', '-', '*', '/');
 		$aTerminators = array('(', ';', "\n", "\r");
-		$sFunction = trim($oParserState->consumeUntil($aTerminators, false, true));
+		$sFunction = $oParserState->consumeUntil($aTerminators, false, true);
 		if ($oParserState->peek(1, -1) != '(') {
 			// Found ; or end of line before an opening bracket
 			throw new UnexpectedTokenException('(', $oParserState->peek(1, -1), 'literal', $oParserState->currentLine());
+		} else if (!in_array($sFunction, array('calc', '-moz-calc', '-webkit-calc'))) {
+			// Found invalid calc definition. Example calc (...
+			throw new UnexpectedTokenException('calc', $sFunction, 'literal', $oParserState->currentLine());
 		}
 		$oCalcList = new CalcRuleValueList($oParserState->currentLine());
 		$oList = new RuleValueList(',', $oParserState->currentLine());