dup2, dup3: work around another cygwin crasher

[gnulib.git] / lib / dup2.c

diff --git a/lib/dup2.c b/lib/dup2.c
index 6d3e4fc..f128e7a 100644 (file)
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -1,10 +1,11 @@
 /* Duplicate an open file descriptor to a specified file descriptor.
-   Copyright (C) 1999, 2004 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1999, 2004-2007, 2009-2013 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -12,26 +13,117 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* written by Paul Eggert */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
+
+/* Specification.  */
+#include <unistd.h>
 
 #include <errno.h>
+#include <fcntl.h>
+
+#if HAVE_DUP2
+
+# undef dup2
+
+# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 
-#if HAVE_FCNTL_H
-# include <fcntl.h>
-#endif
+/* Get declarations of the native Windows API functions.  */
+#  define WIN32_LEAN_AND_MEAN
+#  include <windows.h>
 
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+#  include "msvc-inval.h"
+
+/* Get _get_osfhandle.  */
+#  include "msvc-nothrow.h"
 
-#ifndef F_DUPFD
+static int
+ms_windows_dup2 (int fd, int desired_fd)
+{
+  int result;
+
+  /* If fd is closed, mingw hangs on dup2 (fd, fd).  If fd is open,
+     dup2 (fd, fd) returns 0, but all further attempts to use fd in
+     future dup2 calls will hang.  */
+  if (fd == desired_fd)
+    {
+      if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE)
+        {
+          errno = EBADF;
+          return -1;
+        }
+      return fd;
+    }
+
+  /* Wine 1.0.1 return 0 when desired_fd is negative but not -1:
+     http://bugs.winehq.org/show_bug.cgi?id=21289 */
+  if (desired_fd < 0)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  TRY_MSVC_INVAL
+    {
+      result = dup2 (fd, desired_fd);
+    }
+  CATCH_MSVC_INVAL
+    {
+      errno = EBADF;
+      result = -1;
+    }
+  DONE_MSVC_INVAL;
+
+  if (result == 0)
+    result = desired_fd;
+
+  return result;
+}
+
+#  define dup2 ms_windows_dup2
+
+# endif
+
+int
+rpl_dup2 (int fd, int desired_fd)
+{
+  int result;
+
+# ifdef F_GETFL
+  /* On Linux kernels 2.6.26-2.6.29, dup2 (fd, fd) returns -EBADF.
+     On Cygwin 1.5.x, dup2 (1, 1) returns 0.
+     On Cygwin 1.7.17, dup2 (1, -1) dumps core.
+     On Cygwin 1.7.25, dup2 (1, 256) can dump core.
+     On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC.  */
+#  if HAVE_SETDTABLESIZE
+  setdtablesize (desired_fd + 1);
+#  endif
+  if (desired_fd < 0)
+    fd = desired_fd;
+  if (fd == desired_fd)
+    return fcntl (fd, F_GETFL) == -1 ? -1 : fd;
+# endif
+
+  result = dup2 (fd, desired_fd);
+
+  /* Correct an errno value on FreeBSD 6.1 and Cygwin 1.5.x.  */
+  if (result == -1 && errno == EMFILE)
+    errno = EBADF;
+# if REPLACE_FCHDIR
+  if (fd != desired_fd && result != -1)
+    result = _gl_register_dup (fd, result);
+# endif
+  return result;
+}
+
+#else /* !HAVE_DUP2 */
+
+/* On older platforms, dup2 did not exist.  */
+
+# ifndef F_DUPFD
 static int
 dupfd (int fd, int desired_fd)
 {
@@ -47,17 +139,26 @@ dupfd (int fd, int desired_fd)
       return r;
     }
 }
-#endif
+# endif
 
 int
 dup2 (int fd, int desired_fd)
 {
-  if (fd == desired_fd)
-    return fd;
+  int result = fcntl (fd, F_GETFL) < 0 ? -1 : fd;
+  if (result == -1 || fd == desired_fd)
+    return result;
   close (desired_fd);
-#ifdef F_DUPFD
-  return fcntl (fd, F_DUPFD, desired_fd);
-#else
-  return dupfd (fd, desired_fd);
-#endif
+# ifdef F_DUPFD
+  result = fcntl (fd, F_DUPFD, desired_fd);
+#  if REPLACE_FCHDIR
+  if (0 <= result)
+    result = _gl_register_dup (fd, result);
+#  endif
+# else
+  result = dupfd (fd, desired_fd);
+# endif
+  if (result == -1 && (errno == EMFILE || errno == EINVAL))
+    errno = EBADF;
+  return result;
 }
+#endif /* !HAVE_DUP2 */