X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fbtowc.m4;h=c4ee4e41970d702254b6538a276cea38c1ebbd4a;hb=91fd3b18b755b77c4bb3f7556ddedb055c16c834;hp=2c75c8fb02a6e8794a140f44f4ce49d86028e4df;hpb=b2e2010c7c902235b5efb5bd3c6529f61b093aa4;p=gnulib.git

diff --git a/m4/btowc.m4 b/m4/btowc.m4
index 2c75c8fb0..c4ee4e419 100644
--- a/m4/btowc.m4
+++ b/m4/btowc.m4
@@ -1,4 +1,4 @@
-# btowc.m4 serial 5
+# btowc.m4 serial 6
 dnl Copyright (C) 2008-2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -18,10 +18,39 @@ AC_DEFUN([gl_FUNC_BTOWC],
     HAVE_BTOWC=0
   else
 
-    dnl IRIX 6.5 btowc(EOF) is 0xFF, not WEOF.
     AC_REQUIRE([AC_PROG_CC])
     AC_REQUIRE([gt_LOCALE_FR])
     AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+    dnl Cygwin 1.7.2 btowc('\0') is WEOF, not 0.
+    AC_CACHE_CHECK([whether btowc(0) is correct],
+      [gl_cv_func_btowc_nul],
+      [
+        AC_TRY_RUN([
+#include <stdio.h>
+#include <string.h>
+#include <wchar.h>
+int main ()
+{
+  if (btowc ('\0') != 0)
+    return 1;
+  return 0;
+}],
+          [gl_cv_func_btowc_nul=yes],
+          [gl_cv_func_btowc_nul=no],
+          [
+changequote(,)dnl
+           case "$host_os" in
+                      # Guess no on Cygwin.
+             cygwin*) gl_cv_func_btowc_nul="guessing no" ;;
+                      # Guess yes otherwise.
+             *)       gl_cv_func_btowc_nul="guessing yes" ;;
+           esac
+changequote([,])dnl
+          ])
+      ])
+
+    dnl IRIX 6.5 btowc(EOF) is 0xFF, not WEOF.
     AC_CACHE_CHECK([whether btowc(EOF) is correct],
       [gl_cv_func_btowc_eof],
       [
@@ -55,6 +84,11 @@ int main ()
             [:])
         fi
       ])
+
+    case "$gl_cv_func_btowc_nul" in
+      *yes) ;;
+      *) REPLACE_BTOWC=1 ;;
+    esac
     case "$gl_cv_func_btowc_eof" in
       *yes) ;;
       *) REPLACE_BTOWC=1 ;;