I'll make a couple more comments on the original problem I explained. It looks like you may have identified additional improvements in the process.
I believe the first problem for me is that both mailcap-mime-data and mailcap-user-mime-data are nil. This causes the `error in process filter: mailcap-view-mime: Symbol’s function definition is void: nil` and makes the pdf download and appear in Fundamental mode. This occurs whether I will be using doc-view-mode or pdf-view-mode. I'll use DocView for the rest of this example.
1. emacs -Q
2. M-x eww
This results in the error message and the following:
This can be (partially) corrected by running the following code before the steps 2 and 3:
'((type . "application/pdf")
(viewer . doc-view-mode)))
This chooses a view mode for the pdf but that brings the second problem. This selects the default encoding of raw-text and the conversion fails:
Instead I choose doc-view-mode manually for the eww pdf buffer:
Then selecting binary for the encoding finally gets a viewable pdf:
I hope this is in some way helpful.
On Sat, Oct 31, 2020 at 7:43 AM Basil L. Contovounesios <firstname.lastname@example.org
Nicholas Harrison <email@example.com> writes:
> Using the EWW browser, I can navigate around to webpages, but navigating
> to a pdf fails. It appears to download an unreadable pdf. Downloading
> and viewing the pdf manually in emacs (pdf-view-mode) works fine.
> I've tried these solutions to no avail:
> - Adding "application/pdf; emacsclient %s" to a ~/.mailcap file. This
> makes the process hang indefinitely.
> - Running the following elisp code:
> `(add-to-list 'mailcap-user-mime-data
> '((type . "application/pdf")
> (viewer . pdf-view-mode)))`
> This doesn't seem to have an effect.
Seems to have been fixed on master:
1. emacs -Q
2. M-x eww RET https://www.gnu.org/software/emacs/manual/emacs.html RET
3. C-s extra pdf RET RET
This opens the "Specialized Emacs Features" manual in a *eww pdf* buffer
With PDF Tools and the mailcap-user-mime-data setting above installed,
it opens in pdf-view-mode instead.
I'm surprised the setting for mailcap-user-mime-data is needed though,
since pdf-view-mode appears before doc-view-mode in both
mailcap-mime-data and my version of auto-mode-alist.