[Fix] functional SFC style injection support

Author: blake-newman

lib/component-normalizer.js

@@ -61,9 +61,18 @@ module.exports = function normalizeComponent (
     hook = injectStyles
   }
 
-  if (hook) {
+  var existing = options.functional ? options.render : options.beforeCreate
+
+  if (hook && options.functional && injectStyles) {
+    // inject styles for functioal component in vue file
+    options.render = function renderWithStyleInjection (h, context) {
+      hook(context)
+      return existing(h, context)
+    }
+  }
+
+  if (hook && !options.functional) {
     // inject component registration as beforeCreate hook
-    var existing = options.beforeCreate
     options.beforeCreate = existing
       ? [].concat(existing, hook)
       : [hook]