Bitbucket error 500 on files that only have the merge commit

Error

When we open some files in the UI it returns 500.
After analysing the logs we found that the error was:

"HTTP/1.0" c.a.s.i.w.s.f.AvatarUrlFunction Error getting avatar URL for null
java.lang.NullPointerException: person"

And we assumed that this happens when bitbucket is fetching for the avatar of the person that committed on the file.

Cause:
This is happening with files that were merge from another repository but their history was not kept. So they only have the merge commit. However the command that bitbucket uses to get the commits in the UI is git log --follows and this command ignores the merge commits.
So in the case of those files it returns null (this explains the error).

If we add a new commit to those files git log --follow works and there is no 500 anymore

thank you