bug in jpeg export

[mir07]

Describe the bug
When an image is exported as jpeg from darktable and then parsing image tags using exiftool the following error message is displayed:
"Warning" => "Can't decrypt Nikon information (no ShutterCount key)". The implication is that, among others, the tag LensID is missing. LensID gives a detailed information about the used lens -> "LensID" => "Tamron SP AF 150-600mm f/5-6.3 VC USD (A011)"

To Reproduce
Steps to reproduce the behavior:

1. Use any raw file (NEF): exiftool -LensID image.nef
   Output: Lens ID : Tamron SP AF 150-600mm f/5-6.3 VC USD (A011)
2. Export the raw file to jpeg from Darktable
3. exiftool -LensID image.jpg
   Output: Warning: Can't decrypt Nikon information (no ShutterCount key) - image.jpg

Expected behavior
Step 3 should output:
Lens ID : Tamron SP AF 150-600mm f/5-6.3 VC USD (A011)

Platform (please complete the following information):

• OS: Debian Sid (Unstable)
• Version 2.6.0

Additional context
I Have exported jpg's for 2.4.x which contains the same bug.

[mir07]

I forgot to mention that exporting from Rawtherapee works as expected.

[mir07]

Read more here: LycheeOrg/Lychee#234

[Nilvus]

Maybe it's not a darktable issue. As you said on Lychee, it's the same on Gimp that share libraries. So maybe it's an exiv or lensfun (exiv probably) issue. See which version you use and if lens is recognize correctly by these libraries.
And putting a RAW in this type of issues could help.

[mir07]

Files showing the problem attached.
Use:
exiv2 -Pkyct pr [file.jpg]
exiftool -LensID [file.jpg]

Both works with raw file exported to jpeg with Rawtherapee but only exiv2 works with the exported raw from darktable. I am not able to upload the raw file since it is both to large and it does not conform to the allowed file types for upload.

[mir07]

Forgot:
exiftool -ver
11.16
exiv2 --version
exiv2 0.25 001900 (64 bit build)
darktable --version
this is darktable 2.6.2+13~g0bef6bb76-dirty
rawtherapee -v
RawTherapee, version 5.5

So to the best of my knowledge this is a long standing bug in Darktable's jpg export module since Darktable and Rawtherapee uses the same image processing libraries but apparently darktable introduces bad formatted data into the file which brakes exiftool's tag parser.

[github-actions]

This issue did not get any activity in the past 30 days and will be closed in 7 days if no update occurs. Please check if the master branch has fixed it since then.