Improve check for empty content

This has been removed accidentally by a previous commit.

Author: jhnns

lib/loader.js

@@ -21,7 +21,6 @@ const asyncSassJobQueue = async.queue(sass.render, threadPoolSize - 1);
  * @param {string} content
  */
 function sassLoader(content) {
- content = content || '//';
  const callback = this.async();
  const isSync = typeof callback !== "function";
  const self = this;
@@ -44,6 +43,12 @@ function sassLoader(content) {
  addNormalizedDependency
  ));
 
+ // Skip empty files, otherwise it will stop webpack, see issue #21
+ if (options.data.trim() === "") {
+ callback(null, "");
+ return;
+ }
+
  // start the actual rendering
  asyncSassJobQueue.push(options, (err, result) => {
  if (err) {