close all file descriptors w/ the exception of stdin/stdout/stderr

otherwise, parent's file descriptors are inherited and held open by
the child even if the parent dies

This commit was SVN r7652.

orte/mca/pls/fork/pls_fork_module.c

@@ -209,7 +209,7 @@ static int orte_pls_fork_proc(
         char *param, *param2;
         char *uri;
         char **environ_copy;
-
+        long fd, fdmax = sysconf(_SC_OPEN_MAX);
 #if 0
         /* for gperf - setup a new directory for each executable */
         char path[PATH_MAX];
@@ -327,6 +327,10 @@ static int orte_pls_fork_proc(
         /* setup stdout/stderr */
         orte_iof_base_setup_child(&opts);
 
+        /* close all file descriptors w/ exception of stdin/stdout/stderr */
+        for(fd=3; fd<fdmax; fd++)
+            close(fd);
+
         if (context->argv == NULL) {
             context->argv = malloc(sizeof(char*)*2);
             context->argv[0] = strdup(context->app);