document mingw linker fix and close associated bug

[debian/gzip] / lib / dup2.c

diff --git a/lib/dup2.c b/lib/dup2.c
index f6d0f1c73c5aa3c1fe4d7b66c933d553885df7f6..c7d176728d4ba110fdc9cbf983f6df433d09e116 100644 (file)
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -1,6 +1,6 @@
 /* Duplicate an open file descriptor to a specified file descriptor.
 
-   Copyright (C) 1999, 2004-2007, 2009-2012 Free Software Foundation, Inc.
+   Copyright (C) 1999, 2004-2007, 2009-2018 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
@@ -13,7 +13,7 @@
    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, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 /* written by Paul Eggert */
 
@@ -29,16 +29,45 @@
 
 # undef dup2
 
-# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+# if defined _WIN32 && ! defined __CYGWIN__
 
 /* Get declarations of the native Windows API functions.  */
 #  define WIN32_LEAN_AND_MEAN
 #  include <windows.h>
 
-#  include "msvc-inval.h"
+#  if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#   include "msvc-inval.h"
+#  endif
 
 /* Get _get_osfhandle.  */
-#  include "msvc-nothrow.h"
+#  if GNULIB_MSVC_NOTHROW
+#   include "msvc-nothrow.h"
+#  else
+#   include <io.h>
+#  endif
+
+#  if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+static int
+dup2_nothrow (int fd, int desired_fd)
+{
+  int result;
+
+  TRY_MSVC_INVAL
+    {
+      result = dup2 (fd, desired_fd);
+    }
+  CATCH_MSVC_INVAL
+    {
+      errno = EBADF;
+      result = -1;
+    }
+  DONE_MSVC_INVAL;
+
+  return result;
+}
+#  else
+#   define dup2_nothrow dup2
+#  endif
 
 static int
 ms_windows_dup2 (int fd, int desired_fd)
@@ -59,23 +88,14 @@ ms_windows_dup2 (int fd, int desired_fd)
     }
 
   /* Wine 1.0.1 return 0 when desired_fd is negative but not -1:
-     http://bugs.winehq.org/show_bug.cgi?id=21289 */
+     https://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;
+  result = dup2_nothrow (fd, desired_fd);
 
   if (result == 0)
     result = desired_fd;
@@ -85,6 +105,57 @@ ms_windows_dup2 (int fd, int desired_fd)
 
 #  define dup2 ms_windows_dup2
 
+# elif defined __KLIBC__
+
+#  include <InnoTekLIBC/backend.h>
+
+static int
+klibc_dup2dirfd (int fd, int desired_fd)
+{
+  int tempfd;
+  int dupfd;
+
+  tempfd = open ("NUL", O_RDONLY);
+  if (tempfd == -1)
+    return -1;
+
+  if (tempfd == desired_fd)
+    {
+      close (tempfd);
+
+      char path[_MAX_PATH];
+      if (__libc_Back_ioFHToPath (fd, path, sizeof (path)))
+        return -1;
+
+      return open(path, O_RDONLY);
+    }
+
+  dupfd = klibc_dup2dirfd (fd, desired_fd);
+
+  close (tempfd);
+
+  return dupfd;
+}
+
+static int
+klibc_dup2 (int fd, int desired_fd)
+{
+  int dupfd;
+  struct stat sbuf;
+
+  dupfd = dup2 (fd, desired_fd);
+  if (dupfd == -1 && errno == ENOTSUP \
+      && !fstat (fd, &sbuf) && S_ISDIR (sbuf.st_mode))
+    {
+      close (desired_fd);
+
+      return klibc_dup2dirfd (fd, desired_fd);
+    }
+
+  return dupfd;
+}
+
+#  define dup2 klibc_dup2
 # endif
 
 int
@@ -95,7 +166,14 @@ rpl_dup2 (int fd, int desired_fd)
 # 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