Add gnulib `select' module.

Should fix fport_input_waiting when neither poll nor select nor FIONREAD
are available, which is the case on MinGW.  Thanks to Eli Zaretskii for
the report.

10 files changed, 1881 insertions, 2 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 1714cbb8c..c99a7550b 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil clock-time close connect dirfd duplocale environ extensions flock floor fpieee frexp full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nl_langinfo nproc open pipe2 putenv recv recvfrom regex rename send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat trunc verify vsnprintf warnings wchar
+# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil clock-time close connect dirfd duplocale environ extensions flock floor fpieee frexp full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nl_langinfo nproc open pipe2 putenv recv recvfrom regex rename select send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat trunc verify vsnprintf warnings wchar
 
 AUTOMAKE_OPTIONS = 1.5 gnits subdir-objects
 
@@ -62,6 +62,7 @@ libgnu_la_LDFLAGS += $(ISNANL_LIBM)
 libgnu_la_LDFLAGS += $(LDEXP_LIBM)
 libgnu_la_LDFLAGS += $(LIBSOCKET)
 libgnu_la_LDFLAGS += $(LIB_CLOCK_GETTIME)
+libgnu_la_LDFLAGS += $(LIB_SELECT)
 libgnu_la_LDFLAGS += $(LOG1P_LIBM)
 libgnu_la_LDFLAGS += $(LOG_LIBM)
 libgnu_la_LDFLAGS += $(LTLIBICONV)
@@ -87,6 +88,17 @@ EXTRA_DIST += alignof.h
 
 ## end   gnulib module alignof
 
+## begin gnulib module alloca
+
+
+libgnu_la_LIBADD += @LTALLOCA@
+libgnu_la_DEPENDENCIES += @LTALLOCA@
+EXTRA_DIST += alloca.c
+
+EXTRA_libgnu_la_SOURCES += alloca.c
+
+## end   gnulib module alloca
+
 ## begin gnulib module alloca-opt
 
 BUILT_SOURCES += $(ALLOCA_H)
@@ -371,6 +383,15 @@ EXTRA_DIST += dosname.h
 
 ## end   gnulib module dosname
 
+## begin gnulib module dup2
+
+
+EXTRA_DIST += dup2.c
+
+EXTRA_libgnu_la_SOURCES += dup2.c
+
+## end   gnulib module dup2
+
 ## begin gnulib module duplocale
 
 
@@ -1560,6 +1581,15 @@ EXTRA_DIST += same-inode.h
 
 ## end   gnulib module same-inode
 
+## begin gnulib module select
+
+
+EXTRA_DIST += select.c
+
+EXTRA_libgnu_la_SOURCES += select.c
+
+## end   gnulib module select
+
 ## begin gnulib module send
 
 
@@ -2314,6 +2344,40 @@ EXTRA_DIST += sys_file.in.h
 
 ## end   gnulib module sys_file
 
+## begin gnulib module sys_select
+
+BUILT_SOURCES += sys/select.h
+
+# We need the following in order to create <sys/select.h> when the system
+# doesn't have one that works with the given compiler.
+sys/select.h: sys_select.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(WARN_ON_USE_H)
+	$(AM_V_at)$(MKDIR_P) sys
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+	  sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+	      -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+	      -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+	      -e 's|@''NEXT_SYS_SELECT_H''@|$(NEXT_SYS_SELECT_H)|g' \
+	      -e 's|@''HAVE_SYS_SELECT_H''@|$(HAVE_SYS_SELECT_H)|g' \
+	      -e 's/@''GNULIB_PSELECT''@/$(GNULIB_PSELECT)/g' \
+	      -e 's/@''GNULIB_SELECT''@/$(GNULIB_SELECT)/g' \
+	      -e 's|@''HAVE_WINSOCK2_H''@|$(HAVE_WINSOCK2_H)|g' \
+	      -e 's|@''HAVE_PSELECT''@|$(HAVE_PSELECT)|g' \
+	      -e 's|@''REPLACE_PSELECT''@|$(REPLACE_PSELECT)|g' \
+	      -e 's|@''REPLACE_SELECT''@|$(REPLACE_SELECT)|g' \
+	      -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+	      -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+	      < $(srcdir)/sys_select.in.h; \
+	} > $@-t && \
+	mv $@-t $@
+MOSTLYCLEANFILES += sys/select.h sys/select.h-t
+MOSTLYCLEANDIRS += sys
+
+EXTRA_DIST += sys_select.in.h
+
+## end   gnulib module sys_select
+
 ## begin gnulib module sys_socket
 
 BUILT_SOURCES += sys/socket.h
diff --git a/lib/alloca.c b/lib/alloca.c
new file mode 100644
index 000000000..ee0f01886
--- /dev/null
+++ b/lib/alloca.c
@@ -0,0 +1,478 @@
+/* alloca.c -- allocate automatically reclaimed memory
+   (Mostly) portable public-domain implementation -- D A Gwyn
+
+   This implementation of the PWB library alloca function,
+   which is used to allocate space off the run-time stack so
+   that it is automatically reclaimed upon procedure exit,
+   was inspired by discussions with J. Q. Johnson of Cornell.
+   J.Otto Tennant <jot@cray.com> contributed the Cray support.
+
+   There are some preprocessor constants that can
+   be defined when compiling for your specific system, for
+   improved efficiency; however, the defaults should be okay.
+
+   The general concept of this implementation is to keep
+   track of all alloca-allocated blocks, and reclaim any
+   that are found to be deeper in the stack than the current
+   invocation.  This heuristic does not reclaim storage as
+   soon as it becomes invalid, but it will do so eventually.
+
+   As a special case, alloca(0) reclaims storage without
+   allocating any.  It is a good idea to use alloca(0) in
+   your main control loop, etc. to force garbage collection.  */
+
+#include <config.h>
+
+#include <alloca.h>
+
+#include <string.h>
+#include <stdlib.h>
+
+#ifdef emacs
+# include "lisp.h"
+# include "blockinput.h"
+# ifdef EMACS_FREE
+#  undef free
+#  define free EMACS_FREE
+# endif
+#else
+# define memory_full() abort ()
+#endif
+
+/* If compiling with GCC 2, this file's not needed.  */
+#if !defined (__GNUC__) || __GNUC__ < 2
+
+/* If someone has defined alloca as a macro,
+   there must be some other way alloca is supposed to work.  */
+# ifndef alloca
+
+#  ifdef emacs
+#   ifdef static
+/* actually, only want this if static is defined as ""
+   -- this is for usg, in which emacs must undefine static
+   in order to make unexec workable
+   */
+#    ifndef STACK_DIRECTION
+you
+lose
+-- must know STACK_DIRECTION at compile-time
+/* Using #error here is not wise since this file should work for
+   old and obscure compilers.  */
+#    endif /* STACK_DIRECTION undefined */
+#   endif /* static */
+#  endif /* emacs */
+
+/* If your stack is a linked list of frames, you have to
+   provide an "address metric" ADDRESS_FUNCTION macro.  */
+
+#  if defined (CRAY) && defined (CRAY_STACKSEG_END)
+long i00afunc ();
+#   define ADDRESS_FUNCTION(arg) (char *) i00afunc (&(arg))
+#  else
+#   define ADDRESS_FUNCTION(arg) &(arg)
+#  endif
+
+/* Define STACK_DIRECTION if you know the direction of stack
+   growth for your system; otherwise it will be automatically
+   deduced at run-time.
+
+   STACK_DIRECTION > 0 => grows toward higher addresses
+   STACK_DIRECTION < 0 => grows toward lower addresses
+   STACK_DIRECTION = 0 => direction of growth unknown  */
+
+#  ifndef STACK_DIRECTION
+#   define STACK_DIRECTION      0       /* Direction unknown.  */
+#  endif
+
+#  if STACK_DIRECTION != 0
+
+#   define STACK_DIR    STACK_DIRECTION /* Known at compile-time.  */
+
+#  else /* STACK_DIRECTION == 0; need run-time code.  */
+
+static int stack_dir;           /* 1 or -1 once known.  */
+#   define STACK_DIR    stack_dir
+
+static int
+find_stack_direction (int *addr, int depth)
+{
+  int dir, dummy = 0;
+  if (! addr)
+    addr = &dummy;
+  *addr = addr < &dummy ? 1 : addr == &dummy ? 0 : -1;
+  dir = depth ? find_stack_direction (addr, depth - 1) : 0;
+  return dir + dummy;
+}
+
+#  endif /* STACK_DIRECTION == 0 */
+
+/* An "alloca header" is used to:
+   (a) chain together all alloca'ed blocks;
+   (b) keep track of stack depth.
+
+   It is very important that sizeof(header) agree with malloc
+   alignment chunk size.  The following default should work okay.  */
+
+#  ifndef       ALIGN_SIZE
+#   define ALIGN_SIZE   sizeof(double)
+#  endif
+
+typedef union hdr
+{
+  char align[ALIGN_SIZE];       /* To force sizeof(header).  */
+  struct
+    {
+      union hdr *next;          /* For chaining headers.  */
+      char *deep;               /* For stack depth measure.  */
+    } h;
+} header;
+
+static header *last_alloca_header = NULL;       /* -> last alloca header.  */
+
+/* Return a pointer to at least SIZE bytes of storage,
+   which will be automatically reclaimed upon exit from
+   the procedure that called alloca.  Originally, this space
+   was supposed to be taken from the current stack frame of the
+   caller, but that method cannot be made to work for some
+   implementations of C, for example under Gould's UTX/32.  */
+
+void *
+alloca (size_t size)
+{
+  auto char probe;              /* Probes stack depth: */
+  register char *depth = ADDRESS_FUNCTION (probe);
+
+#  if STACK_DIRECTION == 0
+  if (STACK_DIR == 0)           /* Unknown growth direction.  */
+    STACK_DIR = find_stack_direction (NULL, (size & 1) + 20);
+#  endif
+
+  /* Reclaim garbage, defined as all alloca'd storage that
+     was allocated from deeper in the stack than currently.  */
+
+  {
+    register header *hp;        /* Traverses linked list.  */
+
+#  ifdef emacs
+    BLOCK_INPUT;
+#  endif
+
+    for (hp = last_alloca_header; hp != NULL;)
+      if ((STACK_DIR > 0 && hp->h.deep > depth)
+          || (STACK_DIR < 0 && hp->h.deep < depth))
+        {
+          register header *np = hp->h.next;
+
+          free (hp);            /* Collect garbage.  */
+
+          hp = np;              /* -> next header.  */
+        }
+      else
+        break;                  /* Rest are not deeper.  */
+
+    last_alloca_header = hp;    /* -> last valid storage.  */
+
+#  ifdef emacs
+    UNBLOCK_INPUT;
+#  endif
+  }
+
+  if (size == 0)
+    return NULL;                /* No allocation required.  */
+
+  /* Allocate combined header + user data storage.  */
+
+  {
+    /* Address of header.  */
+    register header *new;
+
+    size_t combined_size = sizeof (header) + size;
+    if (combined_size < sizeof (header))
+      memory_full ();
+
+    new = malloc (combined_size);
+
+    if (! new)
+      memory_full ();
+
+    new->h.next = last_alloca_header;
+    new->h.deep = depth;
+
+    last_alloca_header = new;
+
+    /* User storage begins just after header.  */
+
+    return (void *) (new + 1);
+  }
+}
+
+#  if defined (CRAY) && defined (CRAY_STACKSEG_END)
+
+#   ifdef DEBUG_I00AFUNC
+#    include <stdio.h>
+#   endif
+
+#   ifndef CRAY_STACK
+#    define CRAY_STACK
+#    ifndef CRAY2
+/* Stack structures for CRAY-1, CRAY X-MP, and CRAY Y-MP */
+struct stack_control_header
+  {
+    long shgrow:32;             /* Number of times stack has grown.  */
+    long shaseg:32;             /* Size of increments to stack.  */
+    long shhwm:32;              /* High water mark of stack.  */
+    long shsize:32;             /* Current size of stack (all segments).  */
+  };
+
+/* The stack segment linkage control information occurs at
+   the high-address end of a stack segment.  (The stack
+   grows from low addresses to high addresses.)  The initial
+   part of the stack segment linkage control information is
+   0200 (octal) words.  This provides for register storage
+   for the routine which overflows the stack.  */
+
+struct stack_segment_linkage
+  {
+    long ss[0200];              /* 0200 overflow words.  */
+    long sssize:32;             /* Number of words in this segment.  */
+    long ssbase:32;             /* Offset to stack base.  */
+    long:32;
+    long sspseg:32;             /* Offset to linkage control of previous
+                                   segment of stack.  */
+    long:32;
+    long sstcpt:32;             /* Pointer to task common address block.  */
+    long sscsnm;                /* Private control structure number for
+                                   microtasking.  */
+    long ssusr1;                /* Reserved for user.  */
+    long ssusr2;                /* Reserved for user.  */
+    long sstpid;                /* Process ID for pid based multi-tasking.  */
+    long ssgvup;                /* Pointer to multitasking thread giveup.  */
+    long sscray[7];             /* Reserved for Cray Research.  */
+    long ssa0;
+    long ssa1;
+    long ssa2;
+    long ssa3;
+    long ssa4;
+    long ssa5;
+    long ssa6;
+    long ssa7;
+    long sss0;
+    long sss1;
+    long sss2;
+    long sss3;
+    long sss4;
+    long sss5;
+    long sss6;
+    long sss7;
+  };
+
+#    else /* CRAY2 */
+/* The following structure defines the vector of words
+   returned by the STKSTAT library routine.  */
+struct stk_stat
+  {
+    long now;                   /* Current total stack size.  */
+    long maxc;                  /* Amount of contiguous space which would
+                                   be required to satisfy the maximum
+                                   stack demand to date.  */
+    long high_water;            /* Stack high-water mark.  */
+    long overflows;             /* Number of stack overflow ($STKOFEN) calls.  */
+    long hits;                  /* Number of internal buffer hits.  */
+    long extends;               /* Number of block extensions.  */
+    long stko_mallocs;          /* Block allocations by $STKOFEN.  */
+    long underflows;            /* Number of stack underflow calls ($STKRETN).  */
+    long stko_free;             /* Number of deallocations by $STKRETN.  */
+    long stkm_free;             /* Number of deallocations by $STKMRET.  */
+    long segments;              /* Current number of stack segments.  */
+    long maxs;                  /* Maximum number of stack segments so far.  */
+    long pad_size;              /* Stack pad size.  */
+    long current_address;       /* Current stack segment address.  */
+    long current_size;          /* Current stack segment size.  This
+                                   number is actually corrupted by STKSTAT to
+                                   include the fifteen word trailer area.  */
+    long initial_address;       /* Address of initial segment.  */
+    long initial_size;          /* Size of initial segment.  */
+  };
+
+/* The following structure describes the data structure which trails
+   any stack segment.  I think that the description in 'asdef' is
+   out of date.  I only describe the parts that I am sure about.  */
+
+struct stk_trailer
+  {
+    long this_address;          /* Address of this block.  */
+    long this_size;             /* Size of this block (does not include
+                                   this trailer).  */
+    long unknown2;
+    long unknown3;
+    long link;                  /* Address of trailer block of previous
+                                   segment.  */
+    long unknown5;
+    long unknown6;
+    long unknown7;
+    long unknown8;
+    long unknown9;
+    long unknown10;
+    long unknown11;
+    long unknown12;
+    long unknown13;
+    long unknown14;
+  };
+
+#    endif /* CRAY2 */
+#   endif /* not CRAY_STACK */
+
+#   ifdef CRAY2
+/* Determine a "stack measure" for an arbitrary ADDRESS.
+   I doubt that "lint" will like this much.  */
+
+static long
+i00afunc (long *address)
+{
+  struct stk_stat status;
+  struct stk_trailer *trailer;
+  long *block, size;
+  long result = 0;
+
+  /* We want to iterate through all of the segments.  The first
+     step is to get the stack status structure.  We could do this
+     more quickly and more directly, perhaps, by referencing the
+     $LM00 common block, but I know that this works.  */
+
+  STKSTAT (&status);
+
+  /* Set up the iteration.  */
+
+  trailer = (struct stk_trailer *) (status.current_address
+                                    + status.current_size
+                                    - 15);
+
+  /* There must be at least one stack segment.  Therefore it is
+     a fatal error if "trailer" is null.  */
+
+  if (trailer == 0)
+    abort ();
+
+  /* Discard segments that do not contain our argument address.  */
+
+  while (trailer != 0)
+    {
+      block = (long *) trailer->this_address;
+      size = trailer->this_size;
+      if (block == 0 || size == 0)
+        abort ();
+      trailer = (struct stk_trailer *) trailer->link;
+      if ((block <= address) && (address < (block + size)))
+        break;
+    }
+
+  /* Set the result to the offset in this segment and add the sizes
+     of all predecessor segments.  */
+
+  result = address - block;
+
+  if (trailer == 0)
+    {
+      return result;
+    }
+
+  do
+    {
+      if (trailer->this_size <= 0)
+        abort ();
+      result += trailer->this_size;
+      trailer = (struct stk_trailer *) trailer->link;
+    }
+  while (trailer != 0);
+
+  /* We are done.  Note that if you present a bogus address (one
+     not in any segment), you will get a different number back, formed
+     from subtracting the address of the first block.  This is probably
+     not what you want.  */
+
+  return (result);
+}
+
+#   else /* not CRAY2 */
+/* Stack address function for a CRAY-1, CRAY X-MP, or CRAY Y-MP.
+   Determine the number of the cell within the stack,
+   given the address of the cell.  The purpose of this
+   routine is to linearize, in some sense, stack addresses
+   for alloca.  */
+
+static long
+i00afunc (long address)
+{
+  long stkl = 0;
+
+  long size, pseg, this_segment, stack;
+  long result = 0;
+
+  struct stack_segment_linkage *ssptr;
+
+  /* Register B67 contains the address of the end of the
+     current stack segment.  If you (as a subprogram) store
+     your registers on the stack and find that you are past
+     the contents of B67, you have overflowed the segment.
+
+     B67 also points to the stack segment linkage control
+     area, which is what we are really interested in.  */
+
+  stkl = CRAY_STACKSEG_END ();
+  ssptr = (struct stack_segment_linkage *) stkl;
+
+  /* If one subtracts 'size' from the end of the segment,
+     one has the address of the first word of the segment.
+
+     If this is not the first segment, 'pseg' will be
+     nonzero.  */
+
+  pseg = ssptr->sspseg;
+  size = ssptr->sssize;
+
+  this_segment = stkl - size;
+
+  /* It is possible that calling this routine itself caused
+     a stack overflow.  Discard stack segments which do not
+     contain the target address.  */
+
+  while (!(this_segment <= address && address <= stkl))
+    {
+#    ifdef DEBUG_I00AFUNC
+      fprintf (stderr, "%011o %011o %011o\n", this_segment, address, stkl);
+#    endif
+      if (pseg == 0)
+        break;
+      stkl = stkl - pseg;
+      ssptr = (struct stack_segment_linkage *) stkl;
+      size = ssptr->sssize;
+      pseg = ssptr->sspseg;
+      this_segment = stkl - size;
+    }
+
+  result = address - this_segment;
+
+  /* If you subtract pseg from the current end of the stack,
+     you get the address of the previous stack segment's end.
+     This seems a little convoluted to me, but I'll bet you save
+     a cycle somewhere.  */
+
+  while (pseg != 0)
+    {
+#    ifdef DEBUG_I00AFUNC
+      fprintf (stderr, "%011o %011o\n", pseg, size);
+#    endif
+      stkl = stkl - pseg;
+      ssptr = (struct stack_segment_linkage *) stkl;
+      size = ssptr->sssize;
+      pseg = ssptr->sspseg;
+      result += size;
+    }
+  return (result);
+}
+
+#   endif /* not CRAY2 */
+#  endif /* CRAY */
+
+# endif /* no alloca */
+#endif /* not GCC 2 */
diff --git a/lib/dup2.c b/lib/dup2.c
new file mode 100644
index 000000000..89b40c466
--- /dev/null
+++ b/lib/dup2.c
@@ -0,0 +1,160 @@
+/* Duplicate an open file descriptor to a specified file descriptor.
+
+   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 Lesser General Public License as published by
+   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
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* written by Paul Eggert */
+
+#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__
+
+/* Get declarations of the native Windows API functions.  */
+#  define WIN32_LEAN_AND_MEAN
+#  include <windows.h>
+
+#  include "msvc-inval.h"
+
+/* Get _get_osfhandle.  */
+#  include "msvc-nothrow.h"
+
+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 Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC.  */
+  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)
+{
+  int duplicated_fd = dup (fd);
+  if (duplicated_fd < 0 || duplicated_fd == desired_fd)
+    return duplicated_fd;
+  else
+    {
+      int r = dupfd (fd, desired_fd);
+      int e = errno;
+      close (duplicated_fd);
+      errno = e;
+      return r;
+    }
+}
+# endif
+
+int
+dup2 (int fd, int desired_fd)
+{
+  int result = fcntl (fd, F_GETFL) < 0 ? -1 : fd;
+  if (result == -1 || fd == desired_fd)
+    return result;
+  close (desired_fd);
+# 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 */
diff --git a/lib/select.c b/lib/select.c
new file mode 100644
index 000000000..13ca15006
--- /dev/null
+++ b/lib/select.c
@@ -0,0 +1,547 @@
+/* Emulation for select(2)
+   Contributed by Paolo Bonzini.
+
+   Copyright 2008-2013 Free Software Foundation, Inc.
+
+   This file is part of gnulib.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, 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
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License along
+   with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+#include <alloca.h>
+#include <assert.h>
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Windows.  */
+
+#include <sys/types.h>
+#include <errno.h>
+#include <limits.h>
+
+#include <winsock2.h>
+#include <windows.h>
+#include <io.h>
+#include <stdio.h>
+#include <conio.h>
+#include <time.h>
+
+/* Get the overridden 'struct timeval'.  */
+#include <sys/time.h>
+
+#include "msvc-nothrow.h"
+
+#undef select
+
+struct bitset {
+  unsigned char in[FD_SETSIZE / CHAR_BIT];
+  unsigned char out[FD_SETSIZE / CHAR_BIT];
+};
+
+/* Declare data structures for ntdll functions.  */
+typedef struct _FILE_PIPE_LOCAL_INFORMATION {
+  ULONG NamedPipeType;
+  ULONG NamedPipeConfiguration;
+  ULONG MaximumInstances;
+  ULONG CurrentInstances;
+  ULONG InboundQuota;
+  ULONG ReadDataAvailable;
+  ULONG OutboundQuota;
+  ULONG WriteQuotaAvailable;
+  ULONG NamedPipeState;
+  ULONG NamedPipeEnd;
+} FILE_PIPE_LOCAL_INFORMATION, *PFILE_PIPE_LOCAL_INFORMATION;
+
+typedef struct _IO_STATUS_BLOCK
+{
+  union {
+    DWORD Status;
+    PVOID Pointer;
+  } u;
+  ULONG_PTR Information;
+} IO_STATUS_BLOCK, *PIO_STATUS_BLOCK;
+
+typedef enum _FILE_INFORMATION_CLASS {
+  FilePipeLocalInformation = 24
+} FILE_INFORMATION_CLASS, *PFILE_INFORMATION_CLASS;
+
+typedef DWORD (WINAPI *PNtQueryInformationFile)
+         (HANDLE, IO_STATUS_BLOCK *, VOID *, ULONG, FILE_INFORMATION_CLASS);
+
+#ifndef PIPE_BUF
+#define PIPE_BUF        512
+#endif
+
+/* Optimized test whether a HANDLE refers to a console.
+   See <http://lists.gnu.org/archive/html/bug-gnulib/2009-08/msg00065.html>.  */
+#define IsConsoleHandle(h) (((intptr_t) (h) & 3) == 3)
+
+static BOOL
+IsSocketHandle (HANDLE h)
+{
+  WSANETWORKEVENTS ev;
+
+  if (IsConsoleHandle (h))
+    return FALSE;
+
+  /* Under Wine, it seems that getsockopt returns 0 for pipes too.
+     WSAEnumNetworkEvents instead distinguishes the two correctly.  */
+  ev.lNetworkEvents = 0xDEADBEEF;
+  WSAEnumNetworkEvents ((SOCKET) h, NULL, &ev);
+  return ev.lNetworkEvents != 0xDEADBEEF;
+}
+
+/* Compute output fd_sets for libc descriptor FD (whose Windows handle is
+   H).  */
+
+static int
+windows_poll_handle (HANDLE h, int fd,
+                     struct bitset *rbits,
+                     struct bitset *wbits,
+                     struct bitset *xbits)
+{
+  BOOL read, write, except;
+  int i, ret;
+  INPUT_RECORD *irbuffer;
+  DWORD avail, nbuffer;
+  BOOL bRet;
+  IO_STATUS_BLOCK iosb;
+  FILE_PIPE_LOCAL_INFORMATION fpli;
+  static PNtQueryInformationFile NtQueryInformationFile;
+  static BOOL once_only;
+
+  read = write = except = FALSE;
+  switch (GetFileType (h))
+    {
+    case FILE_TYPE_DISK:
+      read = TRUE;
+      write = TRUE;
+      break;
+
+    case FILE_TYPE_PIPE:
+      if (!once_only)
+        {
+          NtQueryInformationFile = (PNtQueryInformationFile)
+            GetProcAddress (GetModuleHandle ("ntdll.dll"),
+                            "NtQueryInformationFile");
+          once_only = TRUE;
+        }
+
+      if (PeekNamedPipe (h, NULL, 0, NULL, &avail, NULL) != 0)
+        {
+          if (avail)
+            read = TRUE;
+        }
+      else if (GetLastError () == ERROR_BROKEN_PIPE)
+        ;
+
+      else
+        {
+          /* It was the write-end of the pipe.  Check if it is writable.
+             If NtQueryInformationFile fails, optimistically assume the pipe is
+             writable.  This could happen on Windows 9x, where
+             NtQueryInformationFile is not available, or if we inherit a pipe
+             that doesn't permit FILE_READ_ATTRIBUTES access on the write end
+             (I think this should not happen since Windows XP SP2; WINE seems
+             fine too).  Otherwise, ensure that enough space is available for
+             atomic writes.  */
+          memset (&iosb, 0, sizeof (iosb));
+          memset (&fpli, 0, sizeof (fpli));
+
+          if (!NtQueryInformationFile
+              || NtQueryInformationFile (h, &iosb, &fpli, sizeof (fpli),
+                                         FilePipeLocalInformation)
+              || fpli.WriteQuotaAvailable >= PIPE_BUF
+              || (fpli.OutboundQuota < PIPE_BUF &&
+                  fpli.WriteQuotaAvailable == fpli.OutboundQuota))
+            write = TRUE;
+        }
+      break;
+
+    case FILE_TYPE_CHAR:
+      write = TRUE;
+      if (!(rbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+        break;
+
+      ret = WaitForSingleObject (h, 0);
+      if (ret == WAIT_OBJECT_0)
+        {
+          if (!IsConsoleHandle (h))
+            {
+              read = TRUE;
+              break;
+            }
+
+          nbuffer = avail = 0;
+          bRet = GetNumberOfConsoleInputEvents (h, &nbuffer);
+
+          /* Screen buffers handles are filtered earlier.  */
+          assert (bRet);
+          if (nbuffer == 0)
+            {
+              except = TRUE;
+              break;
+            }
+
+          irbuffer = (INPUT_RECORD *) alloca (nbuffer * sizeof (INPUT_RECORD));
+          bRet = PeekConsoleInput (h, irbuffer, nbuffer, &avail);
+          if (!bRet || avail == 0)
+            {
+              except = TRUE;
+              break;
+            }
+
+          for (i = 0; i < avail; i++)
+            if (irbuffer[i].EventType == KEY_EVENT)
+              read = TRUE;
+        }
+      break;
+
+    default:
+      ret = WaitForSingleObject (h, 0);
+      write = TRUE;
+      if (ret == WAIT_OBJECT_0)
+        read = TRUE;
+
+      break;
+    }
+
+  ret = 0;
+  if (read && (rbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      rbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  if (write && (wbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      wbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  if (except && (xbits->in[fd / CHAR_BIT] & (1 << (fd & (CHAR_BIT - 1)))))
+    {
+      xbits->out[fd / CHAR_BIT] |= (1 << (fd & (CHAR_BIT - 1)));
+      ret++;
+    }
+
+  return ret;
+}
+
+int
+rpl_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds,
+            struct timeval *timeout)
+#undef timeval
+{
+  static struct timeval tv0;
+  static HANDLE hEvent;
+  HANDLE h, handle_array[FD_SETSIZE + 2];
+  fd_set handle_rfds, handle_wfds, handle_xfds;
+  struct bitset rbits, wbits, xbits;
+  unsigned char anyfds_in[FD_SETSIZE / CHAR_BIT];
+  DWORD ret, wait_timeout, nhandles, nsock, nbuffer;
+  MSG msg;
+  int i, fd, rc;
+
+  if (nfds > FD_SETSIZE)
+    nfds = FD_SETSIZE;
+
+  if (!timeout)
+    wait_timeout = INFINITE;
+  else
+    {
+      wait_timeout = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
+
+      /* select is also used as a portable usleep.  */
+      if (!rfds && !wfds && !xfds)
+        {
+          Sleep (wait_timeout);
+          return 0;
+        }
+    }
+
+  if (!hEvent)
+    hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
+
+  handle_array[0] = hEvent;
+  nhandles = 1;
+  nsock = 0;
+
+  /* Copy descriptors to bitsets.  At the same time, eliminate
+     bits in the "wrong" direction for console input buffers
+     and screen buffers, because screen buffers are waitable
+     and they will block until a character is available.  */
+  memset (&rbits, 0, sizeof (rbits));
+  memset (&wbits, 0, sizeof (wbits));
+  memset (&xbits, 0, sizeof (xbits));
+  memset (anyfds_in, 0, sizeof (anyfds_in));
+  if (rfds)
+    for (i = 0; i < rfds->fd_count; i++)
+      {
+        fd = rfds->fd_array[i];
+        h = (HANDLE) _get_osfhandle (fd);
+        if (IsConsoleHandle (h)
+            && !GetNumberOfConsoleInputEvents (h, &nbuffer))
+          continue;
+
+        rbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    rfds = (fd_set *) alloca (sizeof (fd_set));
+
+  if (wfds)
+    for (i = 0; i < wfds->fd_count; i++)
+      {
+        fd = wfds->fd_array[i];
+        h = (HANDLE) _get_osfhandle (fd);
+        if (IsConsoleHandle (h)
+            && GetNumberOfConsoleInputEvents (h, &nbuffer))
+          continue;
+
+        wbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    wfds = (fd_set *) alloca (sizeof (fd_set));
+
+  if (xfds)
+    for (i = 0; i < xfds->fd_count; i++)
+      {
+        fd = xfds->fd_array[i];
+        xbits.in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+        anyfds_in[fd / CHAR_BIT] |= 1 << (fd & (CHAR_BIT - 1));
+      }
+  else
+    xfds = (fd_set *) alloca (sizeof (fd_set));
+
+  /* Zero all the fd_sets, including the application's.  */
+  FD_ZERO (rfds);
+  FD_ZERO (wfds);
+  FD_ZERO (xfds);
+  FD_ZERO (&handle_rfds);
+  FD_ZERO (&handle_wfds);
+  FD_ZERO (&handle_xfds);
+
+  /* Classify handles.  Create fd sets for sockets, poll the others. */
+  for (i = 0; i < nfds; i++)
+    {
+      if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+        continue;
+
+      h = (HANDLE) _get_osfhandle (i);
+      if (!h)
+        {
+          errno = EBADF;
+          return -1;
+        }
+
+      if (IsSocketHandle (h))
+        {
+          int requested = FD_CLOSE;
+
+          /* See above; socket handles are mapped onto select, but we
+             need to map descriptors to handles.  */
+          if (rbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_READ | FD_ACCEPT;
+              FD_SET ((SOCKET) h, rfds);
+              FD_SET ((SOCKET) h, &handle_rfds);
+            }
+          if (wbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_WRITE | FD_CONNECT;
+              FD_SET ((SOCKET) h, wfds);
+              FD_SET ((SOCKET) h, &handle_wfds);
+            }
+          if (xbits.in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            {
+              requested |= FD_OOB;
+              FD_SET ((SOCKET) h, xfds);
+              FD_SET ((SOCKET) h, &handle_xfds);
+            }
+
+          WSAEventSelect ((SOCKET) h, hEvent, requested);
+          nsock++;
+        }
+      else
+        {
+          handle_array[nhandles++] = h;
+
+          /* Poll now.  If we get an event, do not wait below.  */
+          if (wait_timeout != 0
+              && windows_poll_handle (h, i, &rbits, &wbits, &xbits))
+            wait_timeout = 0;
+        }
+    }
+
+  /* Place a sentinel at the end of the array.  */
+  handle_array[nhandles] = NULL;
+
+restart:
+  if (wait_timeout == 0 || nsock == 0)
+    rc = 0;
+  else
+    {
+      /* See if we need to wait in the loop below.  If any select is ready,
+         do MsgWaitForMultipleObjects anyway to dispatch messages, but
+         no need to call select again.  */
+      rc = select (0, &handle_rfds, &handle_wfds, &handle_xfds, &tv0);
+      if (rc == 0)
+        {
+          /* Restore the fd_sets for the other select we do below.  */
+          memcpy (&handle_rfds, rfds, sizeof (fd_set));
+          memcpy (&handle_wfds, wfds, sizeof (fd_set));
+          memcpy (&handle_xfds, xfds, sizeof (fd_set));
+        }
+      else
+        wait_timeout = 0;
+    }
+
+  for (;;)
+    {
+      ret = MsgWaitForMultipleObjects (nhandles, handle_array, FALSE,
+                                       wait_timeout, QS_ALLINPUT);
+
+      if (ret == WAIT_OBJECT_0 + nhandles)
+        {
+          /* new input of some other kind */
+          BOOL bRet;
+          while ((bRet = PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)) != 0)
+            {
+              TranslateMessage (&msg);
+              DispatchMessage (&msg);
+            }
+        }
+      else
+        break;
+    }
+
+  /* If we haven't done it yet, check the status of the sockets.  */
+  if (rc == 0 && nsock > 0)
+    rc = select (0, &handle_rfds, &handle_wfds, &handle_xfds, &tv0);
+
+  if (nhandles > 1)
+    {
+      /* Count results that are not counted in the return value of select.  */
+      nhandles = 1;
+      for (i = 0; i < nfds; i++)
+        {
+          if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+            continue;
+
+          h = (HANDLE) _get_osfhandle (i);
+          if (h == handle_array[nhandles])
+            {
+              /* Not a socket.  */
+              nhandles++;
+              windows_poll_handle (h, i, &rbits, &wbits, &xbits);
+              if (rbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))
+                  || wbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))
+                  || xbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+                rc++;
+            }
+        }
+
+      if (rc == 0 && wait_timeout == INFINITE)
+        {
+          /* Sleep 1 millisecond to avoid busy wait and retry with the
+             original fd_sets.  */
+          memcpy (&handle_rfds, rfds, sizeof (fd_set));
+          memcpy (&handle_wfds, wfds, sizeof (fd_set));
+          memcpy (&handle_xfds, xfds, sizeof (fd_set));
+          SleepEx (1, TRUE);
+          goto restart;
+        }
+    }
+
+  /* Now fill in the results.  */
+  FD_ZERO (rfds);
+  FD_ZERO (wfds);
+  FD_ZERO (xfds);
+  nhandles = 1;
+  for (i = 0; i < nfds; i++)
+    {
+      if ((anyfds_in[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1)))) == 0)
+        continue;
+
+      h = (HANDLE) _get_osfhandle (i);
+      if (h != handle_array[nhandles])
+        {
+          /* Perform handle->descriptor mapping.  */
+          WSAEventSelect ((SOCKET) h, NULL, 0);
+          if (FD_ISSET (h, &handle_rfds))
+            FD_SET (i, rfds);
+          if (FD_ISSET (h, &handle_wfds))
+            FD_SET (i, wfds);
+          if (FD_ISSET (h, &handle_xfds))
+            FD_SET (i, xfds);
+        }
+      else
+        {
+          /* Not a socket.  */
+          nhandles++;
+          if (rbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, rfds);
+          if (wbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, wfds);
+          if (xbits.out[i / CHAR_BIT] & (1 << (i & (CHAR_BIT - 1))))
+            FD_SET (i, xfds);
+        }
+    }
+
+  return rc;
+}
+
+#else /* ! Native Windows.  */
+
+#include <sys/select.h>
+#include <stddef.h> /* NULL */
+#include <errno.h>
+#include <unistd.h>
+
+#undef select
+
+int
+rpl_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds,
+            struct timeval *timeout)
+{
+  int i;
+
+  /* FreeBSD 8.2 has a bug: it does not always detect invalid fds.  */
+  if (nfds < 0 || nfds > FD_SETSIZE)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  for (i = 0; i < nfds; i++)
+    {
+      if (((rfds && FD_ISSET (i, rfds))
+           || (wfds && FD_ISSET (i, wfds))
+           || (xfds && FD_ISSET (i, xfds)))
+          && dup2 (i, i) != i)
+        return -1;
+    }
+
+  /* Interix 3.5 has a bug: it does not support nfds == 0.  */
+  if (nfds == 0)
+    {
+      nfds = 1;
+      rfds = NULL;
+      wfds = NULL;
+      xfds = NULL;
+    }
+  return select (nfds, rfds, wfds, xfds, timeout);
+}
+
+#endif
diff --git a/lib/sys_select.in.h b/lib/sys_select.in.h
new file mode 100644
index 000000000..0e3e32d82
--- /dev/null
+++ b/lib/sys_select.in.h
@@ -0,0 +1,309 @@
+/* Substitute for <sys/select.h>.
+   Copyright (C) 2007-2013 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, 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
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+# if __GNUC__ >= 3
+@PRAGMA_SYSTEM_HEADER@
+# endif
+@PRAGMA_COLUMNS@
+
+/* On OSF/1 and Solaris 2.6, <sys/types.h> and <sys/time.h>
+   both include <sys/select.h>.
+   Simply delegate to the system's header in this case.  */
+#if (@HAVE_SYS_SELECT_H@                                                \
+     && ((defined __osf__ && defined _SYS_TYPES_H_ && defined _OSF_SOURCE) \
+         || (defined __sun && defined _SYS_TYPES_H                      \
+             && (! (defined _XOPEN_SOURCE || defined _POSIX_C_SOURCE)   \
+                 || defined __EXTENSIONS__)))                           \
+     && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H)
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#elif (@HAVE_SYS_SELECT_H@                                              \
+       && ((defined __osf__ && defined _SYS_TIME_H_ && defined _OSF_SOURCE) \
+           || (defined __sun && defined _SYS_TIME_H                     \
+               && (! (defined _XOPEN_SOURCE || defined _POSIX_C_SOURCE) \
+                   || defined __EXTENSIONS__)))                         \
+       && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H)
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+/* On IRIX 6.5, <sys/timespec.h> includes <sys/types.h>, which includes
+   <sys/bsd_types.h>, which includes <sys/select.h>.  At this point we cannot
+   include <signal.h>, because that includes <internal/signal_core.h>, which
+   gives a syntax error because <sys/timespec.h> has not been completely
+   processed.  Simply delegate to the system's header in this case.  */
+#elif @HAVE_SYS_SELECT_H@ && defined __sgi && (defined _SYS_BSD_TYPES_H && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_BSD_TYPES_H)
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_BSD_TYPES_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+/* On OpenBSD 5.0, <pthread.h> includes <sys/types.h>, which includes
+   <sys/select.h>.  At this point we cannot include <signal.h>, because that
+   includes gnulib's pthread.h override, which gives a syntax error because
+   /usr/include/pthread.h has not been completely processed.  Simply delegate
+   to the system's header in this case.  */
+#elif @HAVE_SYS_SELECT_H@ && defined __OpenBSD__ && (defined _PTHREAD_H_ && !defined PTHREAD_MUTEX_INITIALIZER)
+
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#else
+
+#ifndef _@GUARD_PREFIX@_SYS_SELECT_H
+
+/* On many platforms, <sys/select.h> assumes prior inclusion of
+   <sys/types.h>.  Also, mingw defines sigset_t there, instead of
+   in <signal.h> where it belongs.  */
+#include <sys/types.h>
+
+#if @HAVE_SYS_SELECT_H@
+
+/* On OSF/1 4.0, <sys/select.h> provides only a forward declaration
+   of 'struct timeval', and no definition of this type.
+   Also, Mac OS X, AIX, HP-UX, IRIX, Solaris, Interix declare select()
+   in <sys/time.h>.
+   But avoid namespace pollution on glibc systems.  */
+# ifndef __GLIBC__
+#  include <sys/time.h>
+# endif
+
+/* On AIX 7 and Solaris 10, <sys/select.h> provides an FD_ZERO implementation
+   that relies on memset(), but without including <string.h>.
+   But in any case avoid namespace pollution on glibc systems.  */
+# if (defined __OpenBSD__ || defined _AIX || defined __sun || defined __osf__ || defined __BEOS__) \
+     && ! defined __GLIBC__
+#  include <string.h>
+# endif
+
+/* The include_next requires a split double-inclusion guard.  */
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#endif
+
+/* Get definition of 'sigset_t'.
+   But avoid namespace pollution on glibc systems.
+   Do this after the include_next (for the sake of OpenBSD 5.0) but before
+   the split double-inclusion guard (for the sake of Solaris).  */
+#if !(defined __GLIBC__ && !defined __UCLIBC__)
+# include <signal.h>
+#endif
+
+#ifndef _@GUARD_PREFIX@_SYS_SELECT_H
+#define _@GUARD_PREFIX@_SYS_SELECT_H
+
+#if !@HAVE_SYS_SELECT_H@
+/* A platform that lacks <sys/select.h>.  */
+/* Get the 'struct timeval' and 'fd_set' types and the FD_* macros
+   on most platforms.  */
+# include <sys/time.h>
+/* On HP-UX 11, <sys/time.h> provides an FD_ZERO implementation
+   that relies on memset(), but without including <string.h>.  */
+# if defined __hpux
+#  include <string.h>
+# endif
+/* On native Windows platforms:
+   Get the 'fd_set' type.
+   Get the close() declaration before we override it.  */
+# if @HAVE_WINSOCK2_H@
+#  if !defined _GL_INCLUDING_WINSOCK2_H
+#   define _GL_INCLUDING_WINSOCK2_H
+#   include <winsock2.h>
+#   undef _GL_INCLUDING_WINSOCK2_H
+#  endif
+#  include <io.h>
+# endif
+#endif
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+
+/* Fix some definitions from <winsock2.h>.  */
+
+#if @HAVE_WINSOCK2_H@
+
+# if !GNULIB_defined_rpl_fd_isset
+
+/* Re-define FD_ISSET to avoid a WSA call while we are not using
+   network sockets.  */
+static int
+rpl_fd_isset (SOCKET fd, fd_set * set)
+{
+  u_int i;
+  if (set == NULL)
+    return 0;
+
+  for (i = 0; i < set->fd_count; i++)
+    if (set->fd_array[i] == fd)
+      return 1;
+
+  return 0;
+}
+
+#  define GNULIB_defined_rpl_fd_isset 1
+# endif
+
+# undef FD_ISSET
+# define FD_ISSET(fd, set) rpl_fd_isset(fd, set)
+
+#endif
+
+/* Hide some function declarations from <winsock2.h>.  */
+
+#if @HAVE_WINSOCK2_H@
+# if !defined _@GUARD_PREFIX@_UNISTD_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef close
+#   define close close_used_without_including_unistd_h
+#  else
+    _GL_WARN_ON_USE (close,
+                     "close() used without including <unistd.h>");
+#  endif
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef gethostname
+#   define gethostname gethostname_used_without_including_unistd_h
+#  else
+    _GL_WARN_ON_USE (gethostname,
+                     "gethostname() used without including <unistd.h>");
+#  endif
+# endif
+# if !defined _@GUARD_PREFIX@_SYS_SOCKET_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef socket
+#   define socket              socket_used_without_including_sys_socket_h
+#   undef connect
+#   define connect             connect_used_without_including_sys_socket_h
+#   undef accept
+#   define accept              accept_used_without_including_sys_socket_h
+#   undef bind
+#   define bind                bind_used_without_including_sys_socket_h
+#   undef getpeername
+#   define getpeername         getpeername_used_without_including_sys_socket_h
+#   undef getsockname
+#   define getsockname         getsockname_used_without_including_sys_socket_h
+#   undef getsockopt
+#   define getsockopt          getsockopt_used_without_including_sys_socket_h
+#   undef listen
+#   define listen              listen_used_without_including_sys_socket_h
+#   undef recv
+#   define recv                recv_used_without_including_sys_socket_h
+#   undef send
+#   define send                send_used_without_including_sys_socket_h
+#   undef recvfrom
+#   define recvfrom            recvfrom_used_without_including_sys_socket_h
+#   undef sendto
+#   define sendto              sendto_used_without_including_sys_socket_h
+#   undef setsockopt
+#   define setsockopt          setsockopt_used_without_including_sys_socket_h
+#   undef shutdown
+#   define shutdown            shutdown_used_without_including_sys_socket_h
+#  else
+    _GL_WARN_ON_USE (socket,
+                     "socket() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (connect,
+                     "connect() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (accept,
+                     "accept() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (bind,
+                     "bind() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getpeername,
+                     "getpeername() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getsockname,
+                     "getsockname() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getsockopt,
+                     "getsockopt() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (listen,
+                     "listen() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (recv,
+                     "recv() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (send,
+                     "send() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (recvfrom,
+                     "recvfrom() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (sendto,
+                     "sendto() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (setsockopt,
+                     "setsockopt() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (shutdown,
+                     "shutdown() used without including <sys/socket.h>");
+#  endif
+# endif
+#endif
+
+
+#if @GNULIB_PSELECT@
+# if @REPLACE_PSELECT@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef pselect
+#   define pselect rpl_pselect
+#  endif
+_GL_FUNCDECL_RPL (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+_GL_CXXALIAS_RPL (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+# else
+#  if !@HAVE_PSELECT@
+_GL_FUNCDECL_SYS (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+#  endif
+_GL_CXXALIAS_SYS (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+# endif
+_GL_CXXALIASWARN (pselect);
+#elif defined GNULIB_POSIXCHECK
+# undef pselect
+# if HAVE_RAW_DECL_PSELECT
+_GL_WARN_ON_USE (pselect, "pselect is not portable - "
+                 "use gnulib module pselect for portability");
+# endif
+#endif
+
+#if @GNULIB_SELECT@
+# if @REPLACE_SELECT@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef select
+#   define select rpl_select
+#  endif
+_GL_FUNCDECL_RPL (select, int,
+                  (int, fd_set *, fd_set *, fd_set *, struct timeval *));
+_GL_CXXALIAS_RPL (select, int,
+                  (int, fd_set *, fd_set *, fd_set *, struct timeval *));
+# else
+_GL_CXXALIAS_SYS (select, int,
+                  (int, fd_set *, fd_set *, fd_set *, struct timeval *));
+# endif
+_GL_CXXALIASWARN (select);
+#elif @HAVE_WINSOCK2_H@
+# undef select
+# define select select_used_without_requesting_gnulib_module_select
+#elif defined GNULIB_POSIXCHECK
+# undef select
+# if HAVE_RAW_DECL_SELECT
+_GL_WARN_ON_USE (select, "select is not always POSIX compliant - "
+                 "use gnulib module select for portability");
+# endif
+#endif
+
+
+#endif /* _@GUARD_PREFIX@_SYS_SELECT_H */
+#endif /* _@GUARD_PREFIX@_SYS_SELECT_H */
+#endif /* OSF/1 */
diff --git a/m4/dup2.m4 b/m4/dup2.m4
new file mode 100644
index 000000000..269cfdc11
--- /dev/null
+++ b/m4/dup2.m4
@@ -0,0 +1,84 @@
+#serial 19
+dnl Copyright (C) 2002, 2005, 2007, 2009-2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_DUP2],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  m4_ifdef([gl_FUNC_DUP2_OBSOLETE], [
+    AC_CHECK_FUNCS_ONCE([dup2])
+    if test $ac_cv_func_dup2 = no; then
+      HAVE_DUP2=0
+    fi
+  ], [
+    AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.])
+  ])
+  if test $HAVE_DUP2 = 1; then
+    AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
+      [AC_RUN_IFELSE([
+         AC_LANG_PROGRAM([[#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>]],
+           [int result = 0;
+#ifdef FD_CLOEXEC
+            if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1)
+              result |= 1;
+#endif
+            if (dup2 (1, 1) == 0)
+              result |= 2;
+#ifdef FD_CLOEXEC
+            if (fcntl (1, F_GETFD) != FD_CLOEXEC)
+              result |= 4;
+#endif
+            close (0);
+            if (dup2 (0, 0) != -1)
+              result |= 8;
+            /* Many gnulib modules require POSIX conformance of EBADF.  */
+            if (dup2 (2, 1000000) == -1 && errno != EBADF)
+              result |= 16;
+            /* Flush out a cygwin core dump.  */
+            if (dup2 (2, -1) != -1 || errno != EBADF)
+              result |= 32;
+            return result;
+           ])
+        ],
+        [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
+        [case "$host_os" in
+           mingw*) # on this platform, dup2 always returns 0 for success
+             gl_cv_func_dup2_works="guessing no" ;;
+           cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
+             gl_cv_func_dup2_works="guessing no" ;;
+           linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a
+                   # closed fd may yield -EBADF instead of -1 / errno=EBADF.
+             gl_cv_func_dup2_works="guessing no" ;;
+           freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF.
+             gl_cv_func_dup2_works="guessing no" ;;
+           haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC.
+             gl_cv_func_dup2_works="guessing no" ;;
+           *) gl_cv_func_dup2_works="guessing yes" ;;
+         esac])
+      ])
+    case "$gl_cv_func_dup2_works" in
+      *yes) ;;
+      *)
+        REPLACE_DUP2=1
+        ;;
+    esac
+  fi
+  dnl Replace dup2() for supporting the gnulib-defined fchdir() function,
+  dnl to keep fchdir's bookkeeping up-to-date.
+  m4_ifdef([gl_FUNC_FCHDIR], [
+    gl_TEST_FCHDIR
+    if test $HAVE_FCHDIR = 0; then
+      if test $HAVE_DUP2 = 1; then
+        REPLACE_DUP2=1
+      fi
+    fi
+  ])
+])
+
+# Prerequisites of lib/dup2.c.
+AC_DEFUN([gl_PREREQ_DUP2], [])
diff --git a/m4/gnulib-cache.m4 b/m4/gnulib-cache.m4
index c0fd22691..9fb3a9096 100644
--- a/m4/gnulib-cache.m4
+++ b/m4/gnulib-cache.m4
@@ -27,7 +27,7 @@
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil clock-time close connect dirfd duplocale environ extensions flock floor fpieee frexp full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nl_langinfo nproc open pipe2 putenv recv recvfrom regex rename send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat trunc verify vsnprintf warnings wchar
+#   gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil clock-time close connect dirfd duplocale environ extensions flock floor fpieee frexp full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nl_langinfo nproc open pipe2 putenv recv recvfrom regex rename select send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat trunc verify vsnprintf warnings wchar
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([gnulib-local])
@@ -90,6 +90,7 @@ gl_MODULES([
   recvfrom
   regex
   rename
+  select
   send
   sendto
   setenv
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index ce1be65fe..ef150cb3c 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -41,6 +41,7 @@ AC_DEFUN([gl_EARLY],
   AC_REQUIRE([AM_PROG_CC_C_O])
   # Code from module accept:
   # Code from module alignof:
+  # Code from module alloca:
   # Code from module alloca-opt:
   # Code from module announce-gen:
   # Code from module arpa_inet:
@@ -65,6 +66,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module dirname-lgpl:
   # Code from module dosname:
   # Code from module double-slash-root:
+  # Code from module dup2:
   # Code from module duplocale:
   # Code from module environ:
   # Code from module errno:
@@ -158,6 +160,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module safe-read:
   # Code from module safe-write:
   # Code from module same-inode:
+  # Code from module select:
   # Code from module send:
   # Code from module sendto:
   # Code from module servent:
@@ -190,6 +193,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module striconveh:
   # Code from module string:
   # Code from module sys_file:
+  # Code from module sys_select:
   # Code from module sys_socket:
   # Code from module sys_stat:
   # Code from module sys_time:
@@ -238,6 +242,10 @@ AC_DEFUN([gl_INIT],
     AC_LIBOBJ([accept])
   fi
   gl_SYS_SOCKET_MODULE_INDICATOR([accept])
+changequote(,)dnl
+LTALLOCA=`echo "$ALLOCA" | sed -e 's/\.[^.]* /.lo /g;s/\.[^.]*$/.lo/'`
+changequote([, ])dnl
+AC_SUBST([LTALLOCA])
   gl_FUNC_ALLOCA
   gl_HEADER_ARPA_INET
   AC_PROG_MKDIR_P
@@ -287,6 +295,12 @@ AC_DEFUN([gl_INIT],
   gl_DIRENT_MODULE_INDICATOR([dirfd])
   gl_DIRNAME_LGPL
   gl_DOUBLE_SLASH_ROOT
+  gl_FUNC_DUP2
+  if test $HAVE_DUP2 = 0 || test $REPLACE_DUP2 = 1; then
+    AC_LIBOBJ([dup2])
+    gl_PREREQ_DUP2
+  fi
+  gl_UNISTD_MODULE_INDICATOR([dup2])
   gl_FUNC_DUPLOCALE
   if test $REPLACE_DUPLOCALE = 1; then
     AC_LIBOBJ([duplocale])
@@ -587,6 +601,11 @@ AC_DEFUN([gl_INIT],
   gl_MATH_MODULE_INDICATOR([round])
   gl_PREREQ_SAFE_READ
   gl_PREREQ_SAFE_WRITE
+  gl_FUNC_SELECT
+  if test $REPLACE_SELECT = 1; then
+    AC_LIBOBJ([select])
+  fi
+  gl_SYS_SELECT_MODULE_INDICATOR([select])
   AC_REQUIRE([gl_HEADER_SYS_SOCKET])
   if test "$ac_cv_header_winsock2_h" = yes; then
     AC_LIBOBJ([send])
@@ -658,6 +677,8 @@ AC_DEFUN([gl_INIT],
   gl_HEADER_STRING_H
   gl_HEADER_SYS_FILE_H
   AC_PROG_MKDIR_P
+  gl_HEADER_SYS_SELECT
+  AC_PROG_MKDIR_P
   gl_HEADER_SYS_SOCKET
   AC_PROG_MKDIR_P
   gl_HEADER_SYS_STAT_H
@@ -863,6 +884,7 @@ AC_DEFUN([gl_FILE_LIST], [
   doc/gendocs_template
   lib/accept.c
   lib/alignof.h
+  lib/alloca.c
   lib/alloca.in.h
   lib/arpa_inet.in.h
   lib/asnprintf.c
@@ -888,6 +910,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/dirname-lgpl.c
   lib/dirname.h
   lib/dosname.h
+  lib/dup2.c
   lib/duplocale.c
   lib/errno.in.h
   lib/fcntl.in.h
@@ -989,6 +1012,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/safe-write.c
   lib/safe-write.h
   lib/same-inode.h
+  lib/select.c
   lib/send.c
   lib/sendto.c
   lib/setenv.c
@@ -1017,6 +1041,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/string.in.h
   lib/stripslash.c
   lib/sys_file.in.h
+  lib/sys_select.in.h
   lib/sys_socket.c
   lib/sys_socket.in.h
   lib/sys_stat.in.h
@@ -1068,6 +1093,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/dirfd.m4
   m4/dirname.m4
   m4/double-slash-root.m4
+  m4/dup2.m4
   m4/duplocale.m4
   m4/eealloc.m4
   m4/environ.m4
@@ -1158,6 +1184,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/round.m4
   m4/safe-read.m4
   m4/safe-write.m4
+  m4/select.m4
   m4/servent.m4
   m4/setenv.m4
   m4/signal_h.m4
@@ -1180,6 +1207,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/strftime.m4
   m4/string_h.m4
   m4/sys_file_h.m4
+  m4/sys_select_h.m4
   m4/sys_socket_h.m4
   m4/sys_stat_h.m4
   m4/sys_time_h.m4
diff --git a/m4/select.m4 b/m4/select.m4
new file mode 100644
index 000000000..d025355f9
--- /dev/null
+++ b/m4/select.m4
@@ -0,0 +1,113 @@
+# select.m4 serial 7
+dnl Copyright (C) 2009-2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_SELECT],
+[
+  AC_REQUIRE([gl_HEADER_SYS_SELECT])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_REQUIRE([gl_SOCKETS])
+  if test "$ac_cv_header_winsock2_h" = yes; then
+    REPLACE_SELECT=1
+  else
+    dnl On Interix 3.5, select(0, NULL, NULL, NULL, timeout) fails with error
+    dnl EFAULT.
+    AC_CHECK_HEADERS_ONCE([sys/select.h])
+    AC_CACHE_CHECK([whether select supports a 0 argument],
+      [gl_cv_func_select_supports0],
+      [
+        AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#include <sys/types.h>
+#include <sys/time.h>
+#if HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+int main ()
+{
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 5;
+  return select (0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &timeout) < 0;
+}]])], [gl_cv_func_select_supports0=yes], [gl_cv_func_select_supports0=no],
+          [
+changequote(,)dnl
+           case "$host_os" in
+                       # Guess no on Interix.
+             interix*) gl_cv_func_select_supports0="guessing no";;
+                       # Guess yes otherwise.
+             *)        gl_cv_func_select_supports0="guessing yes";;
+           esac
+changequote([,])dnl
+          ])
+      ])
+    case "$gl_cv_func_select_supports0" in
+      *yes) ;;
+      *) REPLACE_SELECT=1 ;;
+    esac
+
+    dnl On FreeBSD 8.2, select() doesn't always reject bad fds.
+    AC_CACHE_CHECK([whether select detects invalid fds],
+      [gl_cv_func_select_detects_ebadf],
+      [
+        AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <sys/time.h>
+#if HAVE_SYS_SELECT_H
+# include <sys/select.h>
+#endif
+#include <unistd.h>
+#include <errno.h>
+]],[[
+  fd_set set;
+  dup2(0, 16);
+  FD_ZERO(&set);
+  FD_SET(16, &set);
+  close(16);
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 5;
+  return select (17, &set, NULL, NULL, &timeout) != -1 || errno != EBADF;
+]])], [gl_cv_func_select_detects_ebadf=yes],
+      [gl_cv_func_select_detects_ebadf=no],
+          [
+           case "$host_os" in
+                    # Guess yes on glibc systems.
+            *-gnu*) gl_cv_func_select_detects_ebadf="guessing yes" ;;
+                    # If we don't know, assume the worst.
+            *)      gl_cv_func_select_detects_ebadf="guessing no" ;;
+           esac
+          ])
+      ])
+    case $gl_cv_func_select_detects_ebadf in
+      *yes) ;;
+      *) REPLACE_SELECT=1 ;;
+    esac
+  fi
+
+  dnl Determine the needed libraries.
+  LIB_SELECT="$LIBSOCKET"
+  if test $REPLACE_SELECT = 1; then
+    case "$host_os" in
+      mingw*)
+        dnl On the MSVC platform, the function MsgWaitForMultipleObjects
+        dnl (used in lib/select.c) requires linking with -luser32. On mingw,
+        dnl it is implicit.
+        AC_LINK_IFELSE(
+          [AC_LANG_SOURCE([[
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+int
+main ()
+{
+  MsgWaitForMultipleObjects (0, NULL, 0, 0, 0);
+  return 0;
+}]])],
+          [],
+          [LIB_SELECT="$LIB_SELECT -luser32"])
+        ;;
+    esac
+  fi
+  AC_SUBST([LIB_SELECT])
+])
diff --git a/m4/sys_select_h.m4 b/m4/sys_select_h.m4
new file mode 100644
index 000000000..496232851
--- /dev/null
+++ b/m4/sys_select_h.m4
@@ -0,0 +1,95 @@
+# sys_select_h.m4 serial 20
+dnl Copyright (C) 2006-2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_HEADER_SYS_SELECT],
+[
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([gl_SYS_SELECT_H_DEFAULTS])
+  AC_CACHE_CHECK([whether <sys/select.h> is self-contained],
+    [gl_cv_header_sys_select_h_selfcontained],
+    [
+      dnl Test against two bugs:
+      dnl 1. On many platforms, <sys/select.h> assumes prior inclusion of
+      dnl    <sys/types.h>.
+      dnl 2. On OSF/1 4.0, <sys/select.h> provides only a forward declaration
+      dnl    of 'struct timeval', and no definition of this type.
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/select.h>]],
+                                         [[struct timeval b;]])],
+        [gl_cv_header_sys_select_h_selfcontained=yes],
+        [gl_cv_header_sys_select_h_selfcontained=no])
+      dnl Test against another bug:
+      dnl 3. On Solaris 10, <sys/select.h> provides an FD_ZERO implementation
+      dnl    that relies on memset(), but without including <string.h>.
+      if test $gl_cv_header_sys_select_h_selfcontained = yes; then
+        AC_COMPILE_IFELSE(
+          [AC_LANG_PROGRAM([[#include <sys/select.h>]],
+                           [[int memset; int bzero;]])
+          ],
+          [AC_LINK_IFELSE(
+             [AC_LANG_PROGRAM([[#include <sys/select.h>]], [[
+                  #undef memset
+                  #define memset nonexistent_memset
+                  extern
+                  #ifdef __cplusplus
+                  "C"
+                  #endif
+                  void *memset (void *, int, unsigned long);
+                  #undef bzero
+                  #define bzero nonexistent_bzero
+                  extern
+                  #ifdef __cplusplus
+                  "C"
+                  #endif
+                  void bzero (void *, unsigned long);
+                  fd_set fds;
+                  FD_ZERO (&fds);
+                ]])
+             ],
+             [],
+             [gl_cv_header_sys_select_h_selfcontained=no])
+          ])
+      fi
+    ])
+  dnl <sys/select.h> is always overridden, because of GNULIB_POSIXCHECK.
+  gl_CHECK_NEXT_HEADERS([sys/select.h])
+  if test $ac_cv_header_sys_select_h = yes; then
+    HAVE_SYS_SELECT_H=1
+  else
+    HAVE_SYS_SELECT_H=0
+  fi
+  AC_SUBST([HAVE_SYS_SELECT_H])
+  gl_PREREQ_SYS_H_WINSOCK2
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[
+/* Some systems require prerequisite headers.  */
+#include <sys/types.h>
+#if !(defined __GLIBC__ && !defined __UCLIBC__) && HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include <sys/select.h>
+    ]], [pselect select])
+])
+
+AC_DEFUN([gl_SYS_SELECT_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_SYS_SELECT_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_SYS_SELECT_H_DEFAULTS],
+[
+  GNULIB_PSELECT=0; AC_SUBST([GNULIB_PSELECT])
+  GNULIB_SELECT=0; AC_SUBST([GNULIB_SELECT])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_PSELECT=1; AC_SUBST([HAVE_PSELECT])
+  REPLACE_PSELECT=0; AC_SUBST([REPLACE_PSELECT])
+  REPLACE_SELECT=0; AC_SUBST([REPLACE_SELECT])
+])