wchar.h: improve wchar_t support in Bionic

Change-Id: Iffd41046fd0933c66542abf7627a1569522dfcb2
diff --git a/libc/wchar/wcslcpy.c b/libc/wchar/wcslcpy.c
new file mode 100644
index 0000000..b104a06
--- /dev/null
+++ b/libc/wchar/wcslcpy.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *	from OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp
+ */
+
+#include <sys/cdefs.h>
+#if 0
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: wcslcpy.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
+#endif /* LIBC_SCCS and not lint */
+#endif
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <wchar.h>
+
+/*
+ * Copy src to string dst of size siz.  At most siz-1 characters
+ * will be copied.  Always NUL terminates (unless siz == 0).
+ * Returns wcslen(src); if retval >= siz, truncation occurred.
+ */
+size_t
+wcslcpy(wchar_t *dst, const wchar_t *src, size_t siz)
+{
+	wchar_t *d = dst;
+	const wchar_t *s = src;
+	size_t n = siz;
+
+	/* Copy as many bytes as will fit */
+	if (n != 0 && --n != 0) {
+		do {
+			if ((*d++ = *s++) == 0)
+				break;
+		} while (--n != 0);
+	}
+
+	/* Not enough room in dst, add NUL and traverse rest of src */
+	if (n == 0) {
+		if (siz != 0)
+			*d = '\0';		/* NUL-terminate dst */
+		while (*s++)
+			;
+	}
+
+	return(s - src - 1);	/* count does not include NUL */
+}