Chromium displays form fields of a PDF different/wrong

[Randall Whitman]

With Evince-3.36.10-0ubuntu1, fill in US-IRS PDF Y2020 tax forms (f1040, f1040s1, f1040s2) and save.

With PDF-Arranger 1.4.2-1:
[+] t2210-f1040.pdf
[+] t2210-1040s1.pdf
[+] t2210-1040s2.pdf
Export (down-arrow icon) t2210-tax-cat2.pdf - popped up warnings in dialog box:

The metadata field /Accessibility with value 'structured; tagged' has no XMP equivalent, so it was discarded
The metadata field /Form with value 'fillable' has no XMP equivalent, so it was discarded

Display of t2210-tax-cat2.pdf page 3 (f1040 s1):

* chromium-browser-106.0.5249.91: incorrectly displays form entry in lines 2b, 5, 7, 8-lhs, 11, 13, 16, 21.
* evince-3.36.10-0ubuntu1: correct (lines 1, 3, 9, 14 only)
* firefox-104: correct (lines 1, 3, 9, 14 only)
* xpdf-3.04-7: correct (lines 1, 3, 9, 14 only)

Display of t2210-tax-cat2.pdf page 4 (f1040 s2):

* chromium-browser-106.0.5249.91: incorrectly displays form entry in lines 1, 3, 6, 7b, 8, 8c
* evince-3.36.10-0ubuntu1: correctly blank except lines 4 & 10.
* firefox-104: correctly blank except lines 4 & 10.
* xpdf-3.04-7: correctly blank except lines 4 & 10.

Ubuntu-20.04.5/Linux-5.4.0/amd64

ProblemType: Bug
DistroRelease: Ubuntu 20.04
ProcVersionSignature: Ubuntu 5.4.0-125.141-generic 5.4.195
Uname: Linux 5.4.0-125-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.24
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: Unity:Unity7:ubuntu
Date: Fri Oct 14 20:40:01 2022
EcryptfsInUse: Yes
InstallationDate: Installed on 2018-11-21 (1424 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
Snap: chromium 106.0.5249.119 (latest/stable)
SnapSource: ubuntu/+source/chromium-browser
UpgradeStatus: Upgraded to focal on 2022-07-09 (97 days ago)

[Randall Whitman (ubuntu-whizman)]

Cross-reference https://bugs.launchpad.net/ubuntu/+source/evince/+bug/1924832 filed on Evince

[Nathan Teodosio (nteodosio)]

I can verify that the *cat2*.pdf file matches your description,
displaying incorrectly in Chromium 106.0.5249.119 and correctly on
Evince and Zathura.

  However, if I generate it myself from

   pdfarranger t2210-f1040.pdf t2210-1040s1.pdf t2210-1040s2.pdf

, with PDF-Arranger 1.8.2-1, the problem no longer occurs.

I see two possible conclusions:

- The concatenated file in your zip (and thus 1.4.2-1) has a bug such
that its rendering relies undefined behavior — but I don't know if there
is such a thing; or

- Chromium has a bug and renders a fine PDF incorrectly.

[Randall Whitman (ubuntu-whizman)]

In my assessment, there is almost certainly at least an interoperability issue with Chromium, if it displays markedly different content than multiple other implementations (and the other implementations are consistent between them).

It is possible that there is additionally an issue with certain versions of PDF-Arranger.

[Nathan Teodosio (nteodosio)]

Upstream endorses[1] the first hypothesis. The concatenated PDF is buggy.

[1]: https://bugs.chromium.org/p/chromium/issues/detail?id=1376014#c5

[Randall Whitman (ubuntu-whizman)]

Matching the stated behavior of either Acrobat or libpoppler, would be an improvement for chromium.