fix continue downloading after reopening store files

lib/torrent.js

@@ -31,6 +31,8 @@ var uniq = require('uniq')
 var utMetadata = require('ut_metadata')
 var utPex = require('ut_pex') // browser exclude
 var parseRange = require('parse-numeric-range')
+var thunky = require('thunky')
+var raf = require('random-access-file')
 
 var File = require('./file')
 var Peer = require('./peer')
@@ -1602,21 +1604,24 @@ Torrent.prototype._checkDone = function () {
     }
     if (!done) break
   }
-  if (!self.done && done) {
+  if (done) {
     const done = () => {
-    self.done = true
+      self.done = true
       self._debug('torrent done: ' + self.infoHash)
       self.emit('done')
     }
     // flush files to be able to open after download finish
     if(self._store === FSChunkStore)
     {
-      let tasks = self.store.store.files.map(function (file) {
+      let tasks = self.store.store.files.map(function (storeFile) {
         return function (cb) {
-            file.open(function (err, file) {
+            storeFile.open(function (err, file) {
              // an open error is okay because that means the file is not open
              if (err) return cb(null)
-               file.close(cb)
+             file.close(() => {
+                storeFile.open = thunky((cb) => cb(null, raf(storeFile.path)))
+                cb()
+             })
             })
           }
       })