Merge pull request #26 from ashaffer/patch-1

should not return a url when we have a dataUrl

source-map-support.js

@@ -70,6 +70,7 @@ function retrieveSourceMap(source) {
   if (sourceMappingURL.slice(0, dataUrlPrefix.length).toLowerCase() == dataUrlPrefix) {
     // Support source map URL as a data url
     sourceMapData = new Buffer(sourceMappingURL.slice(dataUrlPrefix.length), "base64").toString();
+    sourceMappingURL = null;
   } else {
     // Support source map URLs relative to the source URL
     sourceMappingURL = supportRelativeURL(source, sourceMappingURL);