git-gui: Warn when username and e-mail address is unconfigured?

Hi!

When using Git on Windows, it doesn't pick up a user name from the environment, which leads to commits made by git gui (and probably by git itself) to show up as being made by "unknown <username@.(none)>" (where "username" is the Windows account name).

Is it possible to add a warning to git-gui the first time a commit is attempted if the e-mail address is not configured, and have the user open the configuration dialogue to set up the name properly?