slight open-pipe* / open-process refactor

* libguile/posix.c (scm_open_process): Return the ports as values
  instead of calling out to Scheme again to make-rw-port.  This
  function is private to (ice-9 popen).

* module/ice-9/popen.scm (open-pipe*): Adapt to change.

2 files changed, 16 insertions, 27 deletions

diff --git a/libguile/posix.c b/libguile/posix.c
index ce64256db..4d5fdcf96 100644
--- a/libguile/posix.c
+++ b/libguile/posix.c
@@ -1,5 +1,5 @@
 /* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
- *   2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+ *   2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -1351,7 +1351,7 @@ scm_open_process (SCM mode, SCM prog, SCM args)
   if (pid)
     /* Parent. */
     {
-      SCM read_port = SCM_BOOL_F, write_port = SCM_BOOL_F, port;
+      SCM read_port = SCM_BOOL_F, write_port = SCM_BOOL_F;
 
       /* There is no sense in catching errors on close().  */
       if (reading) 
@@ -1367,25 +1367,8 @@ scm_open_process (SCM mode, SCM prog, SCM args)
           scm_setvbuf (write_port, scm_from_int (_IONBF), SCM_UNDEFINED);
         }
       
-      if (reading && writing)
-        {
-          static SCM make_rw_port = SCM_BOOL_F;
-
-          if (scm_is_false (make_rw_port))
-            make_rw_port = scm_c_private_variable ("ice-9 popen",
-                                                   "make-rw-port");
-
-          port = scm_call_2 (scm_variable_ref (make_rw_port),
-                             read_port, write_port);
-        }
-      else if (reading)
-        port = read_port;
-      else if (writing)
-        port = write_port;
-      else
-        port = scm_sys_make_void_port (mode);
-
-      return scm_cons (port, scm_from_int (pid));
+      return scm_values
+        (scm_list_3 (read_port, write_port, scm_from_int (pid)));
     }
   
   /* The child.  */
diff --git a/module/ice-9/popen.scm b/module/ice-9/popen.scm
index 7ca486805..7d0549eb9 100644
--- a/module/ice-9/popen.scm
+++ b/module/ice-9/popen.scm
@@ -1,6 +1,6 @@
 ;; popen emulation, for non-stdio based ports.
 
-;;;; Copyright (C) 1998, 1999, 2000, 2001, 2003, 2006, 2010, 2011, 2012 Free Software Foundation, Inc.
+;;;; Copyright (C) 1998, 1999, 2000, 2001, 2003, 2006, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
 ;;;; 
 ;;;; This library is free software; you can redistribute it and/or
 ;;;; modify it under the terms of the GNU Lesser General Public
@@ -49,11 +49,17 @@ A port to the process (based on pipes) is created and returned.
 @var{mode} specifies whether an input, an output or an input-output
 port to the process is created: it should be the value of
 @code{OPEN_READ}, @code{OPEN_WRITE} or @code{OPEN_BOTH}."
-  (let* ((port/pid (apply open-process mode command args))
-	 (port (car port/pid)))
-    (pipe-guardian port)
-    (hashq-set! port/pid-table port (cdr port/pid))
-    port))
+  (call-with-values (lambda ()
+                      (apply open-process mode command args))
+    (lambda (read-port write-port pid)
+      (let ((port (or (and read-port write-port
+                           (make-rw-port read-port write-port))
+                      read-port
+                      write-port
+                      (%make-void-port mode))))
+        (pipe-guardian port)
+        (hashq-set! port/pid-table port pid)
+        port))))
 
 (define (open-pipe command mode)
   "Executes the shell command @var{command} (a string) in a subprocess.