-# fpurge.m4 serial 3
-dnl Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+# fpurge.m4 serial 7
+dnl Copyright (C) 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_CHECK_FUNCS_ONCE([fpurge])
AC_CHECK_FUNCS_ONCE([__fpurge])
AC_CHECK_DECLS([fpurge], , , [[#include <stdio.h>]])
- dnl For now, lib/fpurge.c is always compiled.
if test "x$ac_cv_func_fpurge" = xyes; then
- REPLACE_FPURGE=1
+ HAVE_FPURGE=1
+ # Detect BSD bug. Only cygwin 1.7 is known to be immune.
+ AC_CACHE_CHECK([whether fpurge works], [gl_cv_func_fpurge_works],
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>
+]], [FILE *f = fopen ("conftest.txt", "w+");
+ if (!f) return 1;
+ if (fputc ('a', f) != 'a') return 2;
+ rewind (f);
+ if (fgetc (f) != 'a') return 3;
+ if (fgetc (f) != EOF) return 4;
+ if (fpurge (f) != 0) return 5;
+ if (putc ('b', f) != 'b') return 6;
+ if (fclose (f) != 0) return 7;
+ if ((f = fopen ("conftest.txt", "r")) == NULL) return 8;
+ if (fgetc (f) != 'a') return 9;
+ if (fgetc (f) != 'b') return 10;
+ if (fgetc (f) != EOF) return 11;
+ if (fclose (f) != 0) return 12;
+ if (remove ("conftest.txt") != 0) return 13;
+ return 0;])],
+ [gl_cv_func_fpurge_works=yes], [gl_cv_func_fpurge_works=no],
+ [gl_cv_func_fpurge_works='guessing no'])])
+ if test "x$gl_cv_func_fpurge_works" != xyes; then
+ REPLACE_FPURGE=1
+ fi
+ else
+ HAVE_FPURGE=0
fi
if test "x$ac_cv_have_decl_fpurge" = xno; then
HAVE_DECL_FPURGE=0