workaround for new webr format

routes/cdn.js

@@ -39,7 +39,15 @@ function tar_index_files(input){
     var extract = tar.extract({allowUnknownFormat: true})
       .on('entry', process_entry)
       .on('finish', finish_stream)
-      .on('error', reject);
+      .on('error', function(err){
+        if (err.message.includes('Unexpected end') && files.length > 0){
+          finish_stream(); //workaround tar-stream bug for custom webr 0.4.2 tar headers
+        } else {
+          reject(err);
+        }
+      });
+
+
     input.pipe(gunzip()).pipe(extract);
   });
 }
@@ -66,7 +74,8 @@ send_from_bucket = function(hash, file, res){
     if(file === `${name}.index` && name.endsWith('gz')){
       return tar_index_files(stream_file(pkg)).then(function(index){
         index.files.forEach(function(entry){
-          entry.filename = entry.filename.match(/\/.*/)[0]; //strip pkg root dir
+          var newname = entry.filename.match(/\/.*/); //strip pkg root dir
+          entry.filename = newname ? newname[0] : "unknown";
         });
         index.gzip = true;
         res.send(index);