>From 97249cf2945e8fe18ed138af20d6e46761fd0470 Mon Sep 17 00:00:00 2001
From: Guilherme de Almeida Suckevicz <address@hidden>
Date: Wed, 14 May 2014 22:06:24 +0100
Subject: [PATCH] getlogin-tests: avoid false failure under sudo/ssh etc.

* modules/getlogin-tests (configure.ac): Check for ttyname().
* tests/test-getlogin.c (main): Don't depend on environment variables
to correlate with getlogin(), since sudo and ssh etc. can tamper
with the LOGNAME and USER env vars.  Instead lookup the name from
the uid associated with the stdin tty.
---
 ChangeLog              |    9 +++++++++
 modules/getlogin-tests |    1 +
 tests/test-getlogin.c  |   36 +++++++++++++++++++++++++++++++-----
 3 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a8b2ee0..19dfba5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2014-05-14  Guilherme de Almeida Suckevicz  <address@hidden>
+
+	getlogin-tests: avoid false failure under sudo/ssh etc.
+	* modules/getlogin-tests (configure.ac): Check for ttyname().
+	* tests/test-getlogin.c (main): Don't depend on environment variables
+	to correlate with getlogin(), since sudo and ssh etc. can tamper
+	with the LOGNAME and USER env vars.  Instead lookup the name from
+	the uid associated with the stdin tty.
+
 2014-05-11  Paul Eggert  <address@hidden>
 
 	mbsstr, quotearg, xstrtol: pacify IRIX 6.5 cc
diff --git a/modules/getlogin-tests b/modules/getlogin-tests
index 795fba7..6facd60 100644
--- a/modules/getlogin-tests
+++ b/modules/getlogin-tests
@@ -6,6 +6,7 @@ tests/macros.h
 Depends-on:
 
 configure.ac:
+AC_CHECK_FUNCS_ONCE([ttyname])
 
 Makefile.am:
 TESTS += test-getlogin
diff --git a/tests/test-getlogin.c b/tests/test-getlogin.c
index 197aed8..32fd893 100644
--- a/tests/test-getlogin.c
+++ b/tests/test-getlogin.c
@@ -27,6 +27,11 @@ SIGNATURE_CHECK (getlogin, char *, (void));
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+#include <pwd.h>
+
+#include <sys/stat.h>
+#include <sys/types.h>
 
 #include "macros.h"
 
@@ -62,11 +67,32 @@ main (void)
 #if !((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__)
   /* Unix platform */
   {
-    const char *name = getenv ("LOGNAME");
-    if (name == NULL || name[0] == '\0')
-      name = getenv ("USER");
-    if (name != NULL && name[0] != '\0')
-      ASSERT (strcmp (buf, name) == 0);
+# if HAVE_TTYNAME
+    const char *tty;
+    struct stat stat_buf;
+    struct passwd *pwd;
+
+    tty = ttyname (STDIN_FILENO);
+    if (tty == NULL)
+      {
+         ASSERT (errno == ENOTTY);
+
+         fprintf (stderr, "Skipping test: stdin is not a tty.\n");
+         return 77;
+      }
+
+    ASSERT (stat (tty, &stat_buf) == 0);
+
+    pwd = getpwuid (stat_buf.st_uid);
+    if (! pwd)
+      {
+         fprintf (stderr, "Skipping test: no name found for uid %d\n",
+                  stat_buf.st_uid);
+         return 77;
+      }
+
+    ASSERT (strcmp (pwd->pw_name, buf) == 0);
+# endif
   }
 #endif
 #if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
-- 
1.7.7.6