A few more items to check for, including libcharset.h, langinfo.h,

locale_charset(), and nl_langinfo().

configure.in

@@ -135,7 +135,7 @@ AC_MSG_RESULT($NOBODY_GROUP)
 AC_DEFINE_UNQUOTED(NOBODY_USER, "nobody", [unprivileged user--e.g. nobody])
 AC_DEFINE_UNQUOTED(NOBODY_GROUP, "$NOBODY_GROUP", [unprivileged group for unprivileged user])
 
-# arrgh. libc in the current debian stable screws up the largefile
+# arrgh. libc in some old debian version screwed up the largefile
 # stuff, getting byte range locking wrong
 AC_CACHE_CHECK([for broken largefile support],rsync_cv_HAVE_BROKEN_LARGEFILE,[
 AC_TRY_RUN([
@@ -299,7 +299,7 @@ AC_CHECK_HEADERS(sys/fcntl.h sys/select.h fcntl.h sys/time.h sys/unistd.h \
     unistd.h utime.h grp.h compat.h sys/param.h ctype.h sys/wait.h \
     sys/ioctl.h sys/filio.h string.h stdlib.h sys/socket.h sys/mode.h \
     sys/un.h glob.h mcheck.h arpa/inet.h arpa/nameser.h locale.h \
-    netdb.h malloc.h float.h limits.h iconv.h)
+    netdb.h malloc.h float.h limits.h iconv.h libcharset.h langinfo.h)
 AC_HEADER_MAJOR
 
 AC_CHECK_SIZEOF(int)
@@ -490,7 +490,7 @@ AC_CHECK_FUNCS(waitpid wait4 getcwd strdup chown chmod lchmod mknod mkfifo \
     memmove lchown vsnprintf snprintf vasprintf asprintf setsid glob strpbrk \
     strlcat strlcpy strtol mallinfo getgroups setgroups geteuid getegid \
     setlocale setmode open64 lseek64 mkstemp64 mtrace va_copy __va_copy \
-    strerror putenv iconv_open)
+    strerror putenv iconv_open locale_charset nl_langinfo)
 
 AC_CHECK_FUNCS(getpgrp tcgetpgrp)
 if test $ac_cv_func_getpgrp = yes; then
@@ -502,9 +502,15 @@ AC_ARG_ENABLE(iconv,
 	    [disable rsync's --iconv option]),
     [], [enable_iconv=$ac_cv_func_iconv_open])
 AH_TEMPLATE([ICONV_OPTION],
-[Define to 1 if you have iconv() and want rsync's --iconv option.])
-if test x"$enable_iconv" = x"yes"; then
-	AC_DEFINE(ICONV_OPTION)
+[Define if you want the --iconv option.  Specifing a value will set the
+default iconv setting (a NULL means no --iconv processing by default).])
+if test x"$enable_iconv" != x"no"; then
+	if test x"$enable_iconv" = x"yes"; then
+		AC_DEFINE(ICONV_OPTION, NULL)
+	else
+		AC_DEFINE_UNQUOTED(ICONV_OPTION, "$enable_iconv")
+	fi
+	AC_DEFINE(UTF8_CHARSET, "UTF-8", [String to pass to iconv() for the UTF-8 charset.])
 fi