support setting the author of a commit

update copy

pkg/commands/git_commands/commit.go

@@ -28,6 +28,12 @@ func (self *CommitCommands) ResetAuthor() error {
 	return self.cmd.New("git commit --allow-empty --only --no-edit --amend --reset-author").Run()
 }
 
+// Sets the commit's author to the supplied value. Value is expected to be of the form 'Name <Email>'
+func (self *CommitCommands) SetAuthor(value string) error {
+	commandStr := fmt.Sprintf("git commit --allow-empty --only --no-edit --amend --author=%s", self.cmd.Quote(value))
+	return self.cmd.New(commandStr).Run()
+}
+
 // ResetToCommit reset to commit
 func (self *CommitCommands) ResetToCommit(sha string, strength string, envVars []string) error {
 	return self.cmd.New(fmt.Sprintf("git reset --%s %s", strength, sha)).

pkg/commands/git_commands/rebase.go

@@ -63,9 +63,21 @@ func (self *RebaseCommands) RewordCommitInEditor(commits []*models.Commit, index
 }
 
 func (self *RebaseCommands) ResetCommitAuthor(commits []*models.Commit, index int) error {
+	return self.GenericAmend(commits, index, func() error {
+		return self.commit.ResetAuthor()
+	})
+}
+
+func (self *RebaseCommands) SetCommitAuthor(commits []*models.Commit, index int, value string) error {
+	return self.GenericAmend(commits, index, func() error {
+		return self.commit.SetAuthor(value)
+	})
+}
+
+func (self *RebaseCommands) GenericAmend(commits []*models.Commit, index int, f func() error) error {
 	if index == 0 {
 		// we've selected the top commit so no rebase is required
-		return self.commit.ResetAuthor()
+		return f()
 	}
 
 	err := self.BeginInteractiveRebaseForCommit(commits, index)
@@ -73,8 +85,8 @@ func (self *RebaseCommands) ResetCommitAuthor(commits []*models.Commit, index in
 		return err
 	}
 
-	// now the selected commit should be our head so we'll amend it with the new author
-	err = self.commit.ResetAuthor()
+	// now the selected commit should be our head so we'll amend it
+	err = f()
 	if err != nil {
 		return err
 	}