Deadname rewriting

[Phil Hord <phil.hord@gmail.com>]

I know name-scrubbing is already covered in filter-branch and other
places. But we have a scenario becoming more common that makes it a
more sensitive topic.

At $work we have a long time employee who has changed their name from
Alice to Bob.  Bob doesn't want anyone to call him "Alice" anymore and
is prone to be offended if they do.  This is called "deadnaming".

We are able to convince most of our work tools to expunge the deadname
from usage anywhere, but git stubbornly calls Bob "Alice" whenever
someone asks for "git blame" or checks in "git log".

We could rewrite history with filter-branch, but that's quite
disruptive.  I found some alternatives.

.mailmap seems perfect for this task, but it doesn't work everywhere
(blame, log, etc.).  Also, it requires the deadname to be forever
proclaimed in the .mailmap file itself.

`git replace` works rather nicely, except all of Bob's old commits
show "replaced" in the decorator list. Also, it doesn't propagate well
from the central server since `refs/replaces` namespace isn't fetched
normally.  But in case anyone wants it, here's what I did:

git log --author=alice.smith --format="%h" --all |
   while read hash ; do
      GIT_EDITOR='sed -i -e s/Alice Smith/Bob Smith/g' -e
's/alice.smith/bob.smith/' \
      git replace --edit $hash
   done
git push origin 'refs/replace/*:refs/replace/*'

I'd quite like the .mailmap solution to work, and I might flesh that
out that some day.

It feels like `.git/info/grafts` would work the best if it could be
distributed with the project, but I'm pretty sure that's a non-starter
for many reasons.

Any other ideas?  Has anyone here encountered this already?