port to GNU hosts, where getuid and friends can fail

* src/groups.c (main):
* src/install.c (need_copy):
* src/su.c (log_su):
* src/test.c (unary_operator):
* src/whoami.c (main):
Don't assume that getuid and friends always succeed.
This fixes the same problem that we recently fixed with 'id'.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/whoami.c b/src/whoami.c
index e563dcf20..1b0c3cdb6 100644
--- a/src/whoami.c
+++ b/src/whoami.c
@@ -61,6 +61,7 @@ main (int argc, char **argv)
 {
   struct passwd *pw;
   uid_t uid;
+  uid_t NO_UID = -1;
 
   initialize_main (&argc, &argv);
   set_program_name (argv[0]);
@@ -81,8 +82,9 @@ main (int argc, char **argv)
       usage (EXIT_FAILURE);
     }
 
+  errno = 0;
   uid = geteuid ();
-  pw = getpwuid (uid);
+  pw = (uid == NO_UID && errno ? NULL : getpwuid (uid));
   if (pw)
     {
       puts (pw->pw_name);