Running filter-branch over a range of commits

Question

git filter-branch --env-filter \'
export GIT_AUTHOR_EMAIL=\"foo@example.com\"
export GIT_AUTHOR_NAME=\"foo\"\' -- commita..commitb

Results in

Answer 1

Enclose you filter commands in an if-statement that checks for that range. You can check whether a commit is within a given range with this command:

git rev-list start..end | grep **fullsha**

The current commit will be stored in $GIT_COMMIT in your filter. So your filter becomes:

git filter-branch --env-filter '
  if git rev-list commita..commitb | grep $GIT_COMMIT; then
    export GIT_AUTHOR_EMAIL="foo@example.com"
    export GIT_AUTHOR_NAME="foo"
  fi' -- ^commita --all

If you want to only rewrite your current branch, replace --all with HEAD