Merge branch 'stable'

[gnulib.git] / m4 / lseek.m4

diff --git a/m4/lseek.m4 b/m4/lseek.m4
index b454884..73c4069 100644 (file)
--- a/m4/lseek.m4
+++ b/m4/lseek.m4
@@ -1,4 +1,4 @@
-# lseek.m4 serial 7
+# lseek.m4 serial 8
 dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,12 +8,18 @@ AC_DEFUN([gl_FUNC_LSEEK],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([AC_PROG_CC])
+  AC_CHECK_HEADERS_ONCE([unistd.h])
   AC_CACHE_CHECK([whether lseek detects pipes], [gl_cv_func_lseek_pipe],
     [if test $cross_compiling = no; then
        AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h> /* for off_t */
 #include <stdio.h> /* for SEEK_CUR */
-#include <unistd.h>]], [[
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#else /* on Windows with MSVC */
+# include <io.h>
+#endif
+]], [[
   /* Exit with success only if stdin is seekable.  */
   return lseek (0, (off_t)0, SEEK_CUR) < 0;
 ]])],