fs.ReadStream: Passing null for file position on all reads except the first read of a range read.

lib/fs.js

@@ -683,9 +683,8 @@ ReadStream.prototype._read = function () {
     allocNewPool();
   }
 
-  if (this.start !== undefined && this.firstRead) {
-    this.pos = this.start;
-    this.firstRead = false;
+  if (self.start !== undefined && self.firstRead) {
+    self.pos = self.start;
   }
 
   // Grab another reference to the pool in the case that while we're in the
@@ -731,7 +730,10 @@ ReadStream.prototype._read = function () {
     self._read();
   }
 
-  fs.read(self.fd, pool, pool.used, toRead, this.pos, afterRead);
+  // pass null for position after we've seeked to the start of a range read
+  // always pass null on a non-range read
+  fs.read(self.fd, pool, pool.used, toRead, (self.firstRead ? self.pos : null), afterRead);
+  self.firstRead = false;
 
   if (self.pos !== undefined) {
     self.pos += toRead;