diff -urNp coreutils-8.6-orig/src/su.c coreutils-8.6/src/su.c

--- coreutils-8.6-orig/src/su.c	2010-11-03 13:56:11.679069689 +0100

+++ coreutils-8.6/src/su.c	2010-11-03 13:56:45.304325661 +0100

@@ -153,6 +153,9 @@ static bool simulate_login;

 /* If true, change some environment vars to indicate the user su'd to.  */

 static bool change_environment;

+/* If true, then don't call setsid() with a command. */

+int same_session = 0;

+

 #ifdef USE_PAM

 static bool _pam_session_opened;

 static bool _pam_cred_established;

@@ -161,6 +164,7 @@ static bool _pam_cred_established;

 static struct option const longopts[] =

 {

   {"command", required_argument, NULL, 'c'},

+  {"session-command", required_argument, NULL, 'C'},

   {"fast", no_argument, NULL, 'f'},

   {"login", no_argument, NULL, 'l'},

   {"preserve-environment", no_argument, NULL, 'p'},

@@ -335,14 +339,27 @@ create_watching_parent (void)

       sigemptyset (&action.sa_mask);

       action.sa_flags = 0;

       sigemptyset (&ourset);

-      if (sigaddset (&ourset, SIGTERM)

-	  || sigaddset (&ourset, SIGALRM)

-	  || sigaction (SIGTERM, &action, NULL)

-	  || sigprocmask (SIG_UNBLOCK, &ourset, NULL))

-	{

+    if (!same_session)

+      {

+        if (sigaddset(&ourset, SIGINT) || sigaddset(&ourset, SIGQUIT))

+          {

+            error (0, errno, _("cannot set signal handler"));

+            caught_signal = true;

+          }

+      }

+    if (!caught_signal && (sigaddset(&ourset, SIGTERM)

+                    || sigaddset(&ourset, SIGALRM)

+                    || sigaction(SIGTERM, &action, NULL)

+                    || sigprocmask(SIG_UNBLOCK, &ourset, NULL))) {

 	  error (0, errno, _("cannot set signal handler"));

 	  caught_signal = true;

 	}

+    if (!caught_signal && !same_session && (sigaction(SIGINT, &action, NULL)

+                                     || sigaction(SIGQUIT, &action, NULL)))

+      {

+        error (0, errno, _("cannot set signal handler"));

+        caught_signal = true;

+      }

     }

   if (!caught_signal)

     {

@@ -627,6 +644,8 @@ Change the effective user id and group i

 \n\

   -, -l, --login               make the shell a login shell\n\

   -c, --command=COMMAND        pass a single COMMAND to the shell with -c\n\

+  --session-command=COMMAND    pass a single COMMAND to the shell with -c\n\

+                               and do not create a new session\n\

   -f, --fast                   pass -f to the shell (for csh or tcsh)\n\

   -m, --preserve-environment   do not reset environment variables\n\

   -p                           same as -m\n\

@@ -649,6 +668,7 @@ main (int argc, char **argv)

   int optc;

   const char *new_user = DEFAULT_USER;

   char *command = NULL;

+  int request_same_session = 0;

   char *shell = NULL;

   struct passwd *pw;

   struct passwd pw_copy;

@@ -674,6 +694,11 @@ main (int argc, char **argv)

           command = optarg;

           break;

+        case 'C':

+          command = optarg;

+          request_same_session = 1;

+          break;

+

         case 'f':

           fast_startup = true;

           break;

@@ -743,6 +768,9 @@ main (int argc, char **argv)

     }

 #endif

+  if (request_same_session || !command || !pw->pw_uid)

+    same_session = 1;

+

   if (!shell && !change_environment)

     shell = getenv ("SHELL");

   if (shell && getuid () != 0 && restricted_shell (pw->pw_shell))

@@ -764,6 +792,8 @@ main (int argc, char **argv)

 #endif

   change_identity (pw);

+  if (!same_session)

+    setsid ();

   /* Set environment after pam_open_session, which may put KRB5CCNAME

      into the pam_env, etc.  */