From 9e242e9cd7fa59736de9e7fc1f2abdd1572b9d54 Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Sun, 24 Mar 2013 01:27:48 +0100
Subject: [PATCH] Add mbstowcs(3).

---
 libc/Makefile         |  1 +
 libc/include/stdlib.h |  2 +-
 libc/mbstowcs.cpp     | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 libc/mbstowcs.cpp

diff --git a/libc/Makefile b/libc/Makefile
index c58ef40f..0ef66759 100644
--- a/libc/Makefile
+++ b/libc/Makefile
@@ -80,6 +80,7 @@ localtime.o \
 localtime_r.o \
 mbrtowc.o \
 mbsrtowcs.o \
+mbstowcs.o \
 mbtowc.o \
 memccpy.o \
 memchr.o \
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index 48427457..0ddf5476 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -81,6 +81,7 @@ ldiv_t ldiv(long, long);
 long long llabs(long long);
 lldiv_t lldiv(long long, long long);
 void* malloc(size_t);
+size_t mbstowcs(wchar_t* restrict, const char* restrict, size_t);
 int mbtowc(wchar_t *restrict, const char* restrict, size_t);
 #if !defined(_SORTIX_SOURCE)
 char* mktemp(char* templ);
@@ -131,7 +132,6 @@ char* l64a(long);
 void lcong48(unsigned short [7]);
 long lrand48(void);
 int mblen(const char*, size_t);
-size_t mbstowcs(wchar_t *restrict, const char* restrict, size_t);
 char* mkdtemp(char*);
 int mkstemp(char*);
 long mrand48(void);
diff --git a/libc/mbstowcs.cpp b/libc/mbstowcs.cpp
new file mode 100644
index 00000000..e5ed34d2
--- /dev/null
+++ b/libc/mbstowcs.cpp
@@ -0,0 +1,38 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library 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 Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    mbstowcs.cpp
+    Convert a multibyte string to a wide-character string.
+
+*******************************************************************************/
+
+#include <stdlib.h>
+#include <wchar.h>
+
+extern "C" size_t mbstowcs(wchar_t* dst, const char* src, size_t n)
+{
+	// Reset the secret conversion state variable in mbsrtowcs that is used when
+	// ps is NULL by successfully converting the empty string. As always, this
+	// is not multithread secure. For some reason, the standards don't mandate
+	// that the conversion state is reset when mbsrtowcs is called with ps=NULL,
+	// which arguably is a feature - but this function is supposed to do it.
+	const char* empty_string = "";
+	mbsrtowcs(NULL, &empty_string, 0, NULL);
+	return mbsrtowcs(dst, &src, n, NULL);
+}