Q:

Microsoft Edge PDF inline issue

Our Rails web app generates PDFs using wkhtmltopdf and sends them to the client. This works in every web browser we've tested it with except Edge.
We've tried rendering the response in a couple of different ways, this is how it was originally:
kit = PDFKit.new(@html_content)
render text: kit.to_pdf, content_type: 'application/pdf'

This opens the PDF viewer with the PDF displaying correctly in every browser that we tested with except Edge where the browser displays: Something's keeping this PDF from opening.
In our application logs, there is the POST request which is the form submission and I can see our app send the pdf file response, then there are subsequent GET requests to the form submission url which error because it's not expecting any GET request to that url. I've no idea what's going on here.
The response headers for the request are:
Cache-Control: max-age=0, private, must-revalidate
Connection: Keep-Alive
Content-Length: 34865
Content-Type: application/pdf; charset=utf-8
Date: Thu, 18 Jun 2015 14:35:30 GMT
Etag: "4baf297d1866339e60e8e893300909a0"
Server: WEBrick/1.3.1 (Ruby/2.0.0/2013-06-27)
Set-Cookie: _APP_session=<long cookie>; path=/; HttpOnly
X-Request-Id: 617580a8-4d7d-43c4-8e49-aeaeafba7b79
X-Runtime: 21.868098
X-XSS-Protection: 1; mode=block
x-content-type-options: nosniff
x-frame-options: SAMEORIGIN
x-ua-compatible: chrome=1

I have also tried using send_data like this:
send_data kit.to_pdf, type: 'application/pdf', disposition: 'inline'

Which results in the following response headers but ultimately the same problem:
Cache-Control: private
Connection: Keep-Alive
Content-Disposition: inline
Content-Length: 34866
Content-Transfer-Encoding: binary
Content-Type: application/pdf
Date: Thu, 18 Jun 2015 14:39:42 GMT
Etag: "11db49f1a26444a38fa2b51f3c3336ed"
Server: WEBrick/1.3.1 (Ruby/2.0.0/2013-06-27)
Set-Cookie: _APP_session=<long cookie>; path=/; HttpOnly
X-Request-Id: 501d9832-b07e-4764-8ecc-f1c1e9a6421e
X-Runtime: 7.054236
X-XSS-Protection: 1; mode=block
x-content-type-options: nosniff
x-frame-options: SAMEORIGIN
x-ua-compatible: chrome=1

If I remove the Content-Disposition: inline header from the above it brings up the save file prompt and downloading the file works fine. We need it to load in the browser window though.
I don't believe it to be a duplicate of this question because it works in IE 9, 10 and 11 and is only a problem with Edge.

A:

It was a bug but Microsoft have fixed it in build 10158! :)

