The "pdfcrop" utility crops an extra space at the top

[sasha1024]

I have a PDF-file that, when being cropped by "pdfcrop", is always cropped at the top by 28 pts more than expected.

For example

    pdfcrop --margins "-734 -14 -43 -42" that.pdf out1.pdf

acts as if I specified "-734 -42 -43 -42".

Trivial

   pdfcrop --margins "0 0 0 0" that.pdf out2.pdf

doesn't leave the PDF intact but removes the 28pt stripe from the top.

Interesting that cutting "0 0 0 0" again, i.e.

   pdfcrop --margins "0 0 0 0" out2.pdf out3.pdf

doesn't seem to change anything.

I'm not an expect, but I see nothing special in the original PDF file (that.pdf). The "pdfinfo" says for it:

    Creator: Adobe InDesign 14.0 (Windows)
    Producer: Adobe PDF Library 15.0
    CreationDate: Wed Aug 28 13:53:19 2019 EEST
    ModDate: Wed Aug 28 13:53:21 2019 EEST
    Tagged: no
    UserProperties: no
    Suspects: no
    Form: none
    JavaScript: no
    Pages: 1
    Encrypted: no
    Page size: 1275.59 x 788.031 pts
    Page rot: 0
    MediaBox: 0.00 0.00 1275.59 788.03
    CropBox: 0.00 0.00 1275.59 788.03
    BleedBox: 0.00 0.00 1275.59 788.03
    TrimBox: 0.00 0.00 1275.59 788.03
    ArtBox: 0.00 0.00 1275.59 788.03
    File size: 910760 bytes
    Optimized: no
    PDF version: 1.4

Passing that PDF through pdftk or qpdf (before using pdfcrop) doesn't change anything (neither in PDF appearance nor in pdfcrop behavior).

I can provide that PDF file, but I prefer to do it privately (there's nothing secret in it, just I'm not sure whether the copyright owner will be happy if I share public it for everyone).

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: texlive-extra-utils 2019.202000218-1
ProcVersionSignature: Ubuntu 5.4.0-58.64-generic 5.4.73
Uname: Linux 5.4.0-58-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: KDE
Date: Thu Dec 24 17:06:56 2020
InstallationDate: Installed on 2020-03-04 (294 days ago)
InstallationMedia: Kubuntu 20.04 LTS "Focal Fossa" - Alpha amd64 (20200304)
PackageArchitecture: all
SourcePackage: texlive-extra
UpgradeStatus: No upgrade log present (probably fresh install)