Fix commits by incorrect username/email

git-filter-branch.sh

#!/bin/sh

# USE:
# git update-ref -d refs/original/refs/heads/master
# ...or:
# git for-each-ref --format="%(refname)" refs/original/ | xargs -n 1 git update-ref -d
# If you see:
# Cannot create a new backup.
# A previous backup already exists in refs/original/
# Force overwriting the backup with -f

git filter-branch --env-filter '
OLD_EMAIL="person@example.com"
CORRECT_NAME="The Person"
CORRECT_EMAIL="person@new.com"
if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi
' --tag-name-filter cat -- --branches --tags