From 467a0d3d0c27ed7e688c040281aced98d37120d2 Mon Sep 17 00:00:00 2001
From: Michael Hoang <enzime@users.noreply.github.com>
Date: Thu, 24 Oct 2024 02:00:15 +1100
Subject: [PATCH] users: prevent deleting the user calling `darwin-rebuild`

`sysadminctl -deleteUser` will only prevent you from deleting the
current user if it's not the last admin and not the last secure token
user, otherwise it will happily oblige.
---
 modules/users/default.nix | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/modules/users/default.nix b/modules/users/default.nix
index ce77d4d9..e8a030b4 100644
--- a/modules/users/default.nix
+++ b/modules/users/default.nix
@@ -149,6 +149,15 @@ in
       echo "setting up users..." >&2
 
       deleteUser() {
+        # TODO: add `darwin.primaryUser` as well
+        if [[ "$1" == "$SUDO_USER" ]]; then
+          printf >&2 '\e[1;31merror: refusing to delete the user calling `darwin-rebuild` (%s), aborting activation\e[0m\n', "$1"
+          exit 1
+        elif [[ "$1" == "root" ]]; then
+          printf >&2 '\e[1;31merror: refusing to delete `root`, aborting activation\e[0m\n', "$1"
+          exit 1
+        fi
+
         fullDiskAccess=false
 
         if cat /Library/Preferences/com.apple.TimeMachine.plist > /dev/null 2>&1; then
@@ -191,8 +200,15 @@ in
         ${optionalString cfg.forceRecreate ''
           u=$(id -u ${name} 2> /dev/null) || true
           if [[ "$u" -eq ${toString v.uid} ]]; then
-            echo "deleting user ${v.name}..." >&2
-            deleteUser ${name}
+            # TODO: add `darwin.primaryUser` as well
+            if [[ ${name} == "$SUDO_USER" ]]; then
+              printf >&2 'warning: not going to recreate the user calling `darwin-rebuild` (%s), skipping...\n' "$SUDO_USER"
+            elif [[ ${name} == "root" ]]; then
+              printf >&2 'warning: not going to recreate root, skipping...\n'
+            else
+              printf >&2 'deleting user ${v.name}...\n'
+              deleteUser ${name}
+            fi
           else
             echo "warning: existing user '${v.name}' has unexpected uid $u, skipping..." >&2
           fi