Subject: bug#28503: 25.3; buffer-file-name returns nil in eww-pdfs

From: Glenn Morris <[email-masked]>
Date: Mon, 18 Sep 2017 20:40:37 -0400

Alex Branham wrote:

> M-x eww
> (navigate to a pdf, I found this by searching "pdf test page"): http://www.orimi.com/pdf-test.pdf
>
> then eval (buffer-file-name)
>
> For me, it returns nil even though the pdf is a file on my computer (somewhere in /tmp for me).

For me, the pdf is displayed using Emacs's Doc View mode.
This converts the pdf to a png and displays the png.
So you aren't viewing the actual pdf file, you can't edit it, etc.
So I don't think it would make sense to set buffer-file-name as if you were.
(There is doc-view--buffer-file-name, an internal variable.)