don't shadow global window.length value

lib/b64.js

@@ -81,18 +81,16 @@ function encodeChunk (uint8, start, end) {
 }
 
 function fromByteArray (uint8) {
-  var i
+  var i, temp, len2
   var len = uint8.length
   var extraBytes = len % 3 // if we have 1 byte left, pad 2 bytes
   var output = ''
   var parts = []
-  var temp, length
   var maxChunkLength = 16383 // must be multiple of 3
 
   // go through the array every three bytes, we'll deal with trailing stuff later
-
-  for (i = 0, length = len - extraBytes; i < length; i += maxChunkLength) {
-    parts.push(encodeChunk(uint8, i, (i + maxChunkLength) > length ? length : (i + maxChunkLength)))
+  for (i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
+    parts.push(encodeChunk(uint8, i, (i + maxChunkLength) > len2 ? len2 : (i + maxChunkLength)))
   }
 
   // pad the end with zeros, but make sure to not forget the extra bytes