From 7665470353aeda94026db669697ad1e1a6b32877 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Sun, 4 Jan 2009 18:05:10 +0000
Subject: [PATCH] Use new mdup(3mLib) function.

It makes descriptor juggling much more reliable.  Increase version
requirement on mLib to 2.1.0.
---
 configure.ac |  2 +-
 exec.c       | 13 +++++--------
 fwd.h        |  1 +
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/configure.ac b/configure.ac
index 64308fb..d5c3316 100644
--- a/configure.ac
+++ b/configure.ac
@@ -56,7 +56,7 @@ AC_SEARCH_LIBS([socket], [socket])
 AC_SEARCH_LIBS([gethostbyname], [nsl resolv])
 
 dnl Packages.
-PKG_CHECK_MODULES([mLib], [mLib >= 2.0.4])
+PKG_CHECK_MODULES([mLib], [mLib >= 2.1.0])
 
 dnl Functions.
 AC_CHECK_FUNCS([inet_aton])
diff --git a/exec.c b/exec.c
index 753fc4c..bdd9b5b 100644
--- a/exec.c
+++ b/exec.c
@@ -464,6 +464,7 @@ static void xept_attach(endpt *e, reffd *in, reffd *out)
 
   if (kid == 0) {
     xopts *xo = xe->xo;
+    mdup_fd md[3];
 
     /* --- Fiddle with the file descriptors --- *
      *
@@ -473,18 +474,14 @@ static void xept_attach(endpt *e, reffd *in, reffd *out)
      */
 
     close(fd[0]);
-    if (dup2(in->fd, STDIN_FILENO) < 0 ||
-	dup2(out->fd, STDOUT_FILENO) < 0 ||
-	dup2(fd[1], STDERR_FILENO) < 0) {
+    md[0].cur = in->fd;  md[0].want = STDIN_FILENO;
+    md[1].cur = out->fd; md[1].want = STDOUT_FILENO;
+    md[2].cur = fd[1];   md[2].want = STDERR_FILENO;
+    if (mdup(md, 3)) {
       moan("couldn't manipulate file descriptors: %s", strerror(errno));
       _exit(1);
     }
 
-    if (in->fd > 2)
-      close(in->fd);
-    if (out->fd > 2)
-      close(out->fd);
-
     fdflags(STDIN_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
     fdflags(STDOUT_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
     fdflags(STDERR_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0);
diff --git a/fwd.h b/fwd.h
index b45f397..6c16fb6 100644
--- a/fwd.h
+++ b/fwd.h
@@ -87,6 +87,7 @@
 #include <mLib/fdflags.h>
 #include <mLib/fdpass.h>
 #include <mLib/ident.h>
+#include <mLib/mdup.h>
 #include <mLib/mdwopt.h>
 #include <mLib/quis.h>
 #include <mLib/report.h>
-- 
2.11.0