exiftool -xmp:all= p.jxl
1 image files updated
exiftool -xmp:subject+="aaa" p.jxl
1 image files updated
exiftool -xmp:all -G1 p.jxl
[XMP-x] XMP Toolkit : Image::ExifTool 12.56
[XMP-dc] Subject : aaa
exiftool -xmp:subject+="bbb" p.jxl
1 image files updated
exiftool -xmp:all -G1 p.jxl
[XMP-x] XMP Toolkit : Image::ExifTool 12.56
[XMP-dc] Subject : bbb
OS : Linux
Phil will have to take a look at this because exiftool is writing multple XMP-dc:Subject. The -a (-duplicates) option (https://exiftool.org/exiftool_pod.html#a---a--duplicates---duplicates) is needed to see what is happening.
C:\>exiftool -G1 -a -s -subject Y:\!temp\dd\p-original.jxl
C:\>exiftool -P -overwrite_original -xmp:subject+="aaa" Y:\!temp\dd\p-original.jxl
Warning: [minor] Ignored empty rdf:Seq list for darktable:masks_history - Y:/!temp/dd/p-original.jxl
1 image files updated
C:\>exiftool -G1 -a -s -subject Y:\!temp\dd\p-original.jxl
[XMP-dc] Subject : aaa
[XMP-dc] Subject : aaa
C:\>exiftool -P -overwrite_original -xmp:subject+="bbb" Y:\!temp\dd\p-original.jxl
1 image files updated
C:\>exiftool -G1 -a -s -subject Y:\!temp\dd\p-original.jxl
[XMP-dc] Subject : aaa, bbb
[XMP-dc] Subject : aaa, bbb
[XMP-dc] Subject : bbb
Great, thanks for this report!
This bug will be fixed in 12.57.
- Phil
Version 12.57 is now available with this fix.
- Phil