1831751 - Print to PDF doesn't support same-document anchor links (e.g. `<a href="#section-1.1">1.1</a>`)

Status: RESOLVED DUPLICATE of bug 1729276

(Core :: Printing: Output, defect)

Description

[chansey97]

Steps to reproduce:

Print a webpage to PDF, but generated .pdf file doesn't support anchor link.

Reproduce steps:

1. Open https://datatracker.ietf.org/doc/html/rfc1945 in Firefox.

Note that in this page I can jump to "1.1 Purpose" section via clicking the hyperlink "1.1" in "Table of Contents".

2. File -> Print... -> Save to PDF -> Save.

Firefox then generates a file "RFC 1945 - Hypertext Transfer Protocol -- HTTP_1.0.pdf"

4. Open that .pdf with a well-known PDF viewer (e.g. Adobe Acrobat) and click the the link "1.1".

Actual results:

Adobe Acrobat opens web browser to https://datatracker.ietf.org/doc/html/rfc1945#section-1.1

Obviously, this is not a expected behavior.

Expected results:

Adobe Acrobat jumps to "1.1 Purpose" section in the PDF.

Note that if the .pdf generated by Google Chrome, there is no problem.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Printing: Output' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Daniel Holbert [:dholbert]]

Thanks for the bug report! I can reproduce. I think we only added support for links in print-to-PDF in the last year or two (I can't find the bug number, but I recall it being part of a cairo upgrade).

jfkthame, do you know if this use-case was supposed to be addressed by that? Or is this a known missing feature in our cairo-based PDF printing backend?

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: pdf generated from Firefox Nightly 114 with print-to-pdf

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: pdf generated from Chrome 115.0.5750.0 (Official Build) dev (64-bit) with print-to-pdf

Comment 5

[Daniel Holbert [:dholbert]]

So in the Firefox print-to-pdf output, the 1.1 link is literally a link to https://datatracker.ietf.org/doc/html/rfc1945#section-1.1 as you can see if you open my first attachment and hover the 1.1 link. If you click it, you get redirected away from the PDF and to that^ site.

In the Chrome print-to-PDF output, the 1.1 link is a local in-doc link, which (as viewed with PDF.js) is pointed at https://bug1831751.bmoattachments.org/attachment.cgi?id=9332310#section-1.1 i.e. the anchor within the same document.

Comment 6

[Jonathan Kew [:jfkthame]]

This is a known limitation. You can try enabling "internal" link destinations by setting print.save_as_pdf.internal_destinations.enabled to true in about:config, but in some cases this results in an error generating the PDF; see bug 1725743. So until that issue is resolved, the feature is disabled by default.

There's been some recent work in this area in upstream cairo, so we should re-examine this and check whether pulling the latest fixes from there will allow us to re-enable internal links. That's bug 1729276, so this is basically a dupe of that issue.