Merge branch 'fix' into maint

* fix:
  Ensure author & committer before asking for commit message.
diff --git a/git-commit.sh b/git-commit.sh
index 26cd7ca..6ef1a9d 100755
--- a/git-commit.sh
+++ b/git-commit.sh
@@ -640,6 +640,8 @@
 		exit 1
 		;;
 	esac
+	git-var GIT_AUTHOR_IDENT > /dev/null  || die
+	git-var GIT_COMMITTER_IDENT > /dev/null  || die
 	${VISUAL:-${EDITOR:-vi}} "$GIT_DIR/COMMIT_EDITMSG"
 	;;
 esac