hard link pointing to itself?

running 13.2-release,
created a tar archive, went to extract on another 13.2-release system,
and got several messages of the form:

$ tar xf tmp.tar path-to-file/filename.jpg:
  Skipping hardlink pointing to itself: path-to-file/filename.jpg:
  File exists

If I go to the source directory on the original system and do:

find . | grep filename.jpg

I see only one file.

Any idea how this file could have been created?  I'm pretty sure
the original was a lower-resolution file written from gimp, but
that wouldn't have been a hard link.  There's a reasonable chance
I tried to create a hard link at some point, but I don't see a
reference to it.  Suspiciously, the tarball had several of these,
and quit after reporting a few on extraction.

How does one tell it's a hard link?  I can get the inode number
using ls -il, but that doesn't tell me much regarding its being
a hard link when there is only one file.

Assuming I don't want to destroy the file, any suggestions on how
to fix it?  Copy to temp, remove/rename old file, rename?

Gary