Move to here from ucs4-utf16.c.

diff --git a/lib/unistr/u16-uctomb-aux.c b/lib/unistr/u16-uctomb-aux.c
new file mode 100644 (file)
index 0000000..7ea56a1
--- /dev/null
+++ b/lib/unistr/u16-uctomb-aux.c
@@ -0,0 +1,60 @@
+/* Conversion UCS-4 to UTF-16.
+   Copyright (C) 2002, 2006-2007 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2002.
+
+   This program is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Library General Public License as published
+   by the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+   USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "unistr.h"
+
+int
+u16_uctomb_aux (uint16_t *s, ucs4_t uc, int n)
+{
+  if (uc < 0xd800)
+    {
+      /* The case n >= 1 is already handled by the caller.  */
+    }
+  else if (uc < 0x10000)
+    {
+      if (uc >= 0xe000)
+       {
+         if (n >= 1)
+           {
+             s[0] = uc;
+             return 1;
+           }
+       }
+      else
+       return -1;
+    }
+  else
+    {
+      if (uc < 0x110000)
+       {
+         if (n >= 2)
+           {
+             s[0] = 0xd800 + ((uc - 0x10000) >> 10);
+             s[1] = 0xdc00 + ((uc - 0x10000) & 0x3ff);
+             return 2;
+           }
+       }
+      else
+       return -1;
+    }
+  return -2;
+}