Bitbucket and Bitbucket backup client fails due to high ascii chars in tags

A user managed to add a tag with a high ascii number character (194 dec = Â).
This resulted in the Bitbucket backup client to crash with the following error:

ERROR (15%) A backup could not be created. Reason: Some files could not be read in Bitbucket home. Please change their permissions to make them readable by the user running the backup client or exclude them from the backup using the bitbucket.home.excludes property and retry. The following files could not be read:

/data/stash-home/shared/data/repositories/nnn/refs/tags/AAA�AA_AAAA_AAAA

Then after a couple of days when the tag was moved to packed-refs, backups do not fail anymore, but when going into the administrative page for the repo in Bitbucket, the following error is displayed (with a grinning 500 error skull):

Error opening/reading [/data/stash-home/shared/data/repositories/nnn/packed-refs]
Please see your system administrator.

As git happily did swallow the character, so should Bitbucket backup client and Bitbucket server.