Canon EF 100mm f/2.8L Macro IS USM not accurately detected

[sans-c]

Describe the bug

EF100mm f/2.8L Macro IS USM yields incorrect value for CanonCs.LensType field (Unknown Lens (254))

To Reproduce

Steps to reproduce the behavior:

1. consider this file:
   

which is an out-of-camera, otherwise unprocessed jpg

2. exiv2 -P kt file | grep Unknown
   results in: Exif.CanonCs.LensType Unknown Lens (254)

Expected behavior

The lens used was a Canon EF 100mm f/2.8L Macro IS USM and should be detected as such.

Desktop (please complete the following information):

• OS and version: Linux (Endeavour)
• Exiv2 version and source: exiv2 0.28.2 from Arch repo

Additional context

The EF lens was mounted to an RF mount via a genuine Canon adapter. No idea if this has any influence. Unfortunately I cannot currently test this lens on an EF-mount.

[kmilos]

Can't reproduce w/ exiv2 0.28.2 on MSYS2 UCRT64 (nor CLANG64):

$ exiv2 -Pkt -g LensType 307813316-fc05b8da-ac3c-4bb3-a5c1-75140b63371a.jpg
Exif.CanonCs.LensType                         Canon EF 100mm f/2.8L Macro IS USM
Exif.CanonFi.RFLensType                       n/a

$ exiv2 -V
exiv2 0.28.2

Possibly related to or duplicate of #2746