X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffpurge.m4;h=ee017d20bf77af52720a39c6ac16d089faae3b14;hb=7ef6c64e210ac0979d7e8ac69bc5b5208c2405ab;hp=1c3ca1033a2c6adbb67877b0ec1fffca6e834e8f;hpb=0d626a9b7c58a25b292252357f5a91110024cfaa;p=gnulib.git

diff --git a/m4/fpurge.m4 b/m4/fpurge.m4
index 1c3ca1033..ee017d20b 100644
--- a/m4/fpurge.m4
+++ b/m4/fpurge.m4
@@ -1,5 +1,5 @@
-# fpurge.m4 serial 3
-dnl Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+# fpurge.m4 serial 7
+dnl Copyright (C) 2007, 2009-2014 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.
@@ -10,9 +10,34 @@ AC_DEFUN([gl_FUNC_FPURGE],
   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