bootstrap: discard non translation project po files

[gnulib.git] / m4 / fflush.m4

diff --git a/m4/fflush.m4 b/m4/fflush.m4
old mode 100755 (executable)
new mode 100644 (file)
index a9889d4..90fd94b
--- a/m4/fflush.m4
+++ b/m4/fflush.m4
@@ -1,6 +1,6 @@
-#serial 1
+# fflush.m4 serial 8
 
-# Copyright (C) 2007 Free Software Foundation, Inc.
+# Copyright (C) 2007-2010 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
@@ -8,8 +8,7 @@
 dnl From Eric Blake
 
 dnl Find out how to obey POSIX semantics of fflush(stdin) discarding
-dnl unread input, rather than C99 undefined semantics.  fpurge is not
-dnl standardized, but has the desired properties.
+dnl unread input on seekable streams, rather than C99 undefined semantics.
 
 AC_DEFUN([gl_FUNC_FFLUSH],
 [
@@ -22,19 +21,41 @@ AC_DEFUN([gl_FUNC_FFLUSH],
 #include <unistd.h>
        ]], [[FILE *f = fopen ("conftest.txt", "r");
          char buffer[10];
-        int fd = fileno (f);
-         if (!f || 0 > fd || fread (buffer, 1, 5, f) != 5)
-          return 2;
-        /* For deterministic results, ensure f read a bigger buffer.  */
-        if (lseek (fd, 0, SEEK_CUR) == 5)
-          return 3;
-        /* POSIX requires fflush-fseek to set file offset of fd.  */
-        if (fflush (f) != 0 || fseek (f, 0, SEEK_CUR) != 0)
-          return 4;
-        return !(lseek (fd, 0, SEEK_CUR) == 5);
+         int fd;
+         int c;
+         if (f == NULL)
+           return 1;
+         fd = fileno (f);
+         if (fd < 0 || fread (buffer, 1, 5, f) != 5)
+           return 2;
+         /* For deterministic results, ensure f read a bigger buffer.  */
+         if (lseek (fd, 0, SEEK_CUR) == 5)
+           return 3;
+         /* POSIX requires fflush-fseek to set file offset of fd.  This fails
+            on BSD systems and on mingw.  */
+         if (fflush (f) != 0 || fseek (f, 0, SEEK_CUR) != 0)
+           return 4;
+         if (lseek (fd, 0, SEEK_CUR) != 5)
+           return 5;
+         /* Verify behaviour of fflush after ungetc. See
+            <http://www.opengroup.org/austin/aardvark/latest/xshbug3.txt>  */
+         /* Verify behaviour of fflush after a backup ungetc.  This fails on
+            mingw.  */
+         c = fgetc (f);
+         ungetc (c, f);
+         fflush (f);
+         if (fgetc (f) != c)
+           return 6;
+         /* Verify behaviour of fflush after a non-backup ungetc.  This fails
+            on glibc 2.8 and on BSD systems.  */
+         c = fgetc (f);
+         ungetc ('@', f);
+         fflush (f);
+         if (fgetc (f) != c)
+           return 7;
+         return 0;
        ]])], [gl_cv_func_fflush_stdin=yes], [gl_cv_func_fflush_stdin=no],
-     [dnl Pessimistically assume fflush is broken.  This is wrong for
-      dnl at least glibc and cygwin; but lib/fflush.c takes this into account.
+     [dnl Pessimistically assume fflush is broken.
       gl_cv_func_fflush_stdin=no])
      rm conftest.txt
     ])
@@ -45,16 +66,16 @@ AC_DEFUN([gl_FUNC_FFLUSH],
 
 AC_DEFUN([gl_REPLACE_FFLUSH],
 [
-  AC_CHECK_HEADERS_ONCE([stdio_ext.h])
-  AC_CHECK_FUNCS_ONCE([fpurge __fpurge])
-dnl Linux documents int fpurge(), but only declares void __fpurge().
-  AC_CHECK_DECLS([fpurge], [], [], [[
-#include <stdio.h>
-#if HAVE_STDIO_EXT_H
-# include <stdio_ext.h>
-#endif
-]])
   AC_LIBOBJ([fflush])
   AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   REPLACE_FFLUSH=1
+  gl_PREREQ_FFLUSH
+  gl_REPLACE_FSEEKO
+])
+
+# Prerequisites of lib/fflush.c.
+AC_DEFUN([gl_PREREQ_FFLUSH],
+[
+  AC_REQUIRE([AC_C_INLINE])
+  :
 ])