anzeige.c: do not fail if dropping of privileges fails due to being non-root

1 files changed, 11 insertions, 7 deletions

diff --git a/anzeige.c b/anzeige.c
index 60ac8f9..90282a2 100644
--- a/anzeige.c
+++ b/anzeige.c
@@ -117,16 +117,20 @@ int main(int argc, char **argv)
 //
 void drop_privileges()
 {
-   /*  Drop superuser privileges in correct order */
+  /*  Drop superuser privileges in correct order */
 
-   if (setgid(99) == -1) {
-      perror("can't drop group privileges");
+  int is_already_unprivileged = 0;
+
+  if (setgid(99) == -1) {
+    perror("can't drop group privileges");
+    if (! (is_already_unprivileged = (errno == 1)))
       exit(-1);
-   }
-   if (setuid(99) == -1) {
-      perror("can't drop user privileges");
+  }
+  if (setuid(99) == -1) {
+    perror("can't drop user privileges");
+    if (is_already_unprivileged != (errno == 1))
       exit(-1);
-   }
+  }
 } // drop_root
 
 void handle_signals(int signo)