Makes things clearer and removes redundant / unused code.

lib/torrent.js

@@ -505,14 +505,12 @@ Torrent.prototype._onMetadata = function (metadata) {
     return new File(self, file)
   })
 
-  // Only select specified files (BEP53)
+  // Select only specified files (BEP53) http://www.bittorrent.org/beps/bep_0053.html
   if (self.so) {
-    var specificFiles = parseRange.parse(self.so)
-    // https://github.com/webtorrent/webtorrent/issues/164
-    self.deselect(0, self.pieces.length - 1, false)
+    var selectOnlyFiles = parseRange.parse(self.so)
 
     self.files.forEach(function (v, i) {
-      specificFiles.indexOf(i) === -1 ? self.files[i].deselect() : self.files[i].select(true)
+      if (selectOnlyFiles.includes(i)) self.files[i].select(true)
     })
   } else {
     // start off selecting the entire torrent with low priority