BUG: Duplication of dc:creator with -tagsfromfile and XMP source and target

[Mac2]

When I run this args file:

-overwrite_original
-m
-use
MWG
-tagsfromfile
input.xmp
-all:all
output.xmp

on the input.xmp file attached below, the resulting output.xmp has a dc:creator tag with two entries instead of one:

<dc:creator>
   <rdf:Seq>
    <rdf:li>Joe Bananna</rdf:li>
    <rdf:li>Joe Bananna</rdf:li>
   </rdf:Seq>

I stripped down everything to the bare minimum, the original args file contains a number of removal tags etc.
The problem is the -use MWG argument. By removing it from the args file I can correct the output.

I use this args file as a generic, sometimes processing RAW files as input, sometimes processing XMP files as input. Maybe -use MWG is not valid when the input file is a XMP file?

[Phil Harvey]

Thanks for this report.

This is a tricky problem.  I have found out why this happens in the code.  This is done purposely so that multiple tags can be copied into a single list when wildcards are used (ie. "-creator<all").  In this case, since there are 2 creator tags extracted (XMP-dc:Creator and MWG:Creator), both get written.  I have to think about how this can be fixed without changing the intended behaviour.

I'll post back here when I know more.

Theoretically, using "-use MWG" should make no difference when the input/output are XMP files.

- Phil

[Mac2]

Thanks for looking into this, Phil!

[Phil Harvey]

Well, I think I have to disable the feature that allows you to do things like "-creator<all".  This feature was added in version 9.14, but this unintended side-effect is problematic.  The work around for anyone who was doing things like "-creator<all" will be to use -addTagsFromFile instead of -tagsFromFile.

So unless I come up with a better solution, or discover other features that this affects, I will revert this change from version 9.14, which should fix the problem you noticed.

- Phil

[Mac2]

Great.

Metadata is really a mess, sometimes. BIG sigh.

Even more so if you try to produce solid and high-quality metadata which works over a wide range of platforms and applications. I think we all cannot thank you enough for creating and maintaining (!) ExifTool!