2010-05-05  Ulrich Drepper  <drepper@redhat.com>

	[BZ #11571]
	* sysdeps/unix/sysv/linux/getlogin_r.c (__getlogin_r_loginuid): Handle
	too small buffers according to the standard.

Index: glibc-2.12-2-gc4ccff1/sysdeps/unix/sysv/linux/getlogin_r.c
===================================================================
--- glibc-2.12-2-gc4ccff1.orig/sysdeps/unix/sysv/linux/getlogin_r.c
+++ glibc-2.12-2-gc4ccff1/sysdeps/unix/sysv/linux/getlogin_r.c
@@ -81,13 +81,22 @@ __getlogin_r_loginuid (name, namesize)
   if (tpwd == NULL)
     goto fail;
 
-  strncpy (name, pwd.pw_name, namesize - 1);
-  name[namesize - 1] = '\0';
+  int result = 0;
+  size_t needed = strlen (pwd.pw_name) + 1;
+  if (needed > namesize)
+    {
+      __set_errno (ERANGE);
+      result = ERANGE;
+      goto out;
+    }
 
+  memcpy (name, pwd.pw_name, needed);
+
+ out:
   if (use_malloc)
     free (buf);
 
-  return 0;
+  return result;
 }