X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=m4%2Flseek.m4;h=f336990709c2636072aacfd763a764da1d12db4a;hb=606dd130bdce412935eca78598923720a7e346c4;hp=075c2f42c2108415cb87a073a313e5178123f044;hpb=e461ff7387db733080824cb94b239d8d1d09c4f3;p=gnulib.git

diff --git a/m4/lseek.m4 b/m4/lseek.m4
index 075c2f42c..f33699070 100644
--- a/m4/lseek.m4
+++ b/m4/lseek.m4
@@ -1,4 +1,4 @@
-# lseek.m4 serial 1
+# lseek.m4 serial 4
 dnl Copyright (C) 2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -9,12 +9,32 @@ AC_DEFUN([gl_FUNC_LSEEK],
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([AC_PROG_CC])
   AC_CACHE_CHECK([whether lseek detects pipes], [gl_cv_func_lseek_pipe],
-    [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <unistd.h>],
-[#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-/* mingw mistakenly returns 0 when trying to seek on pipes.  */
+    [if test $cross_compiling = no; then
+       AC_LINK_IFELSE([
+#include <sys/types.h> /* for off_t */
+#include <stdio.h> /* for SEEK_CUR */
+#include <unistd.h>
+int main ()
+{
+  /* Exit with success only if stdin is seekable.  */
+  return lseek (0, (off_t)0, SEEK_CUR) < 0;
+}],
+	 [if test -s conftest$ac_exeext \
+	     && ./conftest$ac_exeext < conftest.$ac_ext \
+	     && { echo hi | ./conftest$ac_exeext; test $? = 1; }; then
+	    gl_cv_func_lseek_pipe=yes
+	  else
+	    gl_cv_func_lseek_pipe=no
+	  fi],
+	 [gl_cv_func_lseek_pipe=no])
+     else
+       AC_COMPILE_IFELSE([
+#if ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) || defined __BEOS__
+/* mingw and BeOS mistakenly return 0 when trying to seek on pipes.  */
   Choke me.
-#endif])],
-      [gl_cv_func_lseek_pipe=yes], [gl_cv_func_lseek_pipe=no])])
+#endif],
+	 [gl_cv_func_lseek_pipe=yes], [gl_cv_func_lseek_pipe=no])
+     fi])
   if test $gl_cv_func_lseek_pipe = no; then
     gl_REPLACE_LSEEK
   fi