Exporting a .jpg file from a .dng converted earlier with Lightroom Classic does not contain tags

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

As I'm started the process of leaving Lightroom for darktable, I came across a bug. In Lightroom i used to import images as .dng files. I have images that are already tagged in Lightroom and want to continue editing them in darktable, then export to .jpg.

When exporting a jpg from the .dng (originally .NEF converted with Lightroom Classic during the import process) with metadata, tags are missing from the .jpg file. When exporting the jpg from the original .nef (also added tags in Lightroom), the .jpg file contain the tags as expected. In both cases, tags are visible in darktable.

Attached both the .dng and .nef files with their .xmp sidecars and the exported .jpgs as well.

Steps to reproduce

1. Import the .dng and .nef files in darktable
2. Export them as .jpg files (at export module's settings check all the metadata fields except editing history

Expected behavior

Both the resulting .jpg files contain the tags/keywords.

Logfile | Screenshot | Screencast

No response

Commit

No response

Where did you obtain darktable from?

darktable.org / GitHub release

darktable version

5.6.0

What OS are you using?

Windows

What is the version of your OS?

Windows 10 Pro

Describe your system

Do not think that the system is relevant. I could reproduce with a win10 pro Intel i7 with NVIDIA GTX1050Ti notebook and also on another one with Win 11, AMD processor without dedicated GPU.

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

NVIDIA GTX 1050Ti (4GB) with NVIDIA Studio Driver v581.57

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

The issue was present in version 5.4.1 as well.

The .dng and .nef files and their xmps are attached as .txt files.

_DSC0493.dng.txt
_DSC0493.dng.xmp.txt
_DSC0493.NEF.txt
_DSC0493.NEF.xmp.txt

Attached the darktable log file as well, but for some reason it does not contain any entry (I have exported the images on 24.06.2024.

darktable-log.txt

Start by reproducing the export with the attached .dng, .nef, and XMP files, then compare metadata in the resulting JPG files. Trace why tags are preserved for the original .nef but not the Lightroom-converted .dng; done when both exported JPGs retain their keywords with the stated metadata settings.