New webkit renders PDF itself

[msdemlei]

Current Behavior:

When luakit "opens" a PDF, it (well: the embedded webkit) renders it itself rather than handing it over to viewpdf or just downloading it. That behaviour was introduced somewhere between webkit 2.34 and 2.40.

Desired Behavior:

Have a knob (in settings?) to turn off the webkit-internal PDF renderer (if you ask me: I'd make it default off).

How can we reproduce it (step by step):

Link against webkit2gtk 2.40.3 (as in Debian bookworm), follow a link to an application/pdf.

Environment:

Linux Distribution & Version: Debian bookworm
Output of luakit --version:
luakit 2.3.3
built with webkit 2.38.2 (installed version: 2.40.3)

[Hm... now that I read this... could this be trouble?]

[taobert]

[Hm... now that I read this... could this be trouble?]

No, i see the behaviour too with:

# luakit --version
luakit 2.3.3-40-g73ce8add
  built with: webkit 2.40.4 (installed version: 2.40.4)
                 GTK 3.24.38
                GLIB 2.76.4
                SOUP 3.2.2

[henkmet]

The good thing is that webkit now renders the pdf correctly whereas earlier it would be a sure crash (for me). But likewise, I find that I'm very often downloading the file to use my system viewer. A seting would be welcome.

[msdemlei]

I've dug a bit, and over at WebKit, there's even a PR tag for the whole calamity: https://github.com/WebKit/WebKit/pulls?page=2&q=is%3Apr+pdf+is%3Aclosed+label%3APDF, but there are quite a few more PRs that mention "PDF" on top. The one introducing pdfjs in the first place, however, I've not found yet (but then I was was too stingy to clone the whole tree, which looks like several gigabyte-ish).

There's an easy-to-find build-time setting to throw out pdfjs, but I certainly don't want to rebuild webkit (regularly); the code that decides to do some wild iframing for application/pdf, on the other hand, I have not found.

I've also experimented with blocking the webkit-pdfjs-viewer: URI scheme webkit uses internally from within luakit, but that (understandably) results in a white page when clicking a PDF.

So... I guess I'd rather ask around rather than keep on poking blindly. Does anyone know a good place to ask?