Buffer.slice is broken for Windows Edge users and in Firefox developer edition

[jcalfee]

We noticed that some Windows Edge users and in the latest developer edition of Firefox (v49) Buffer slice is failing. We successfully worked around the problem by setting TYPED_ARRAY_SUPPORT = false. The issue happens when this.subarray(start, end) returns the wrong results. You can see the problem with this test: new Buffer("abc").slice(0, 2) === "abc" .. This will return true if you have the bug.

I believe this.subarray is native so I have also reported this issue here: https://bugzilla.mozilla.org/show_bug.cgi?id=1280052

Buffer.prototype.slice = function slice (start, end) {
...
 var newBuf
  if (Buffer.TYPED_ARRAY_SUPPORT) {
    newBuf = Buffer._augment(this.subarray(start, end))
  } else {
    var sliceLen = end - start
    newBuf = new Buffer(sliceLen, undefined)
    for (var i = 0; i < sliceLen; i++) {
      newBuf[i] = this[i + start]
    }
  }
...

[feross]

It looks like you're using an old version of this library. You can use npm ls buffer to see which packages are depending on buffer. The current version of buffer is 4.6.0.

[feross]

This issue is fixed in the latest version of buffer.

[nolanlawson]

By any chance was an issue filed on Edge as well? We care a lot about library compat and want to make sure we don't break the ecosystem.

Here's our issue tracker. A complete Gist to reproduce would be really helpful (or at least which version of buffer you're using so that we can reproduce).

[feross]

@nolanlawson This issue was fixed by #97 a while ago.

[nolanlawson]

Ah OK, got it. I'll add a comment to the Mozilla bug.