"0" can be the only valid unitless number string

src/renderers/dom/shared/dangerousStyleValue.js

@@ -44,7 +44,7 @@ function dangerousStyleValue(name, value, component) {
   }
 
   var isNonNumeric = isNaN(value);
-  if (isNonNumeric || value === 0 ||
+  if (isNonNumeric || value === 0 || value === '0' ||
       isUnitlessNumber.hasOwnProperty(name) && isUnitlessNumber[name]) {
     return '' + value; // cast to string
   }