From 5fcb637cb20323d492dcaf3d349cff577b865258 Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Wed, 19 Sep 2012 22:33:13 +0000
Subject: [PATCH] [CRT] Implement mbstowcs_s. passes all crt apitests.

svn path=/trunk/; revision=57345
---
 reactos/dll/win32/msvcrt/msvcrt.spec    |   2 +-
 reactos/lib/sdk/crt/crt.cmake           |   1 +
 reactos/lib/sdk/crt/string/mbstowcs_s.c | 117 ++++++++++++++++++++++++
 3 files changed, 119 insertions(+), 1 deletion(-)
 create mode 100644 reactos/lib/sdk/crt/string/mbstowcs_s.c

diff --git a/reactos/dll/win32/msvcrt/msvcrt.spec b/reactos/dll/win32/msvcrt/msvcrt.spec
index 9b6a73fdf12..8ac2e5643e9 100644
--- a/reactos/dll/win32/msvcrt/msvcrt.spec
+++ b/reactos/dll/win32/msvcrt/msvcrt.spec
@@ -1272,7 +1272,7 @@
 # stub mbsrtowcs
 # stub mbsrtowcs_s
 @ cdecl mbstowcs(ptr str long)
-# stub mbstowcs_s
+@ cdecl mbstowcs_s(ptr ptr long str long)
 @ cdecl mbtowc(wstr str long)
 @ cdecl memchr(ptr long long)
 @ cdecl memcmp(ptr ptr long)
diff --git a/reactos/lib/sdk/crt/crt.cmake b/reactos/lib/sdk/crt/crt.cmake
index 226f45fdaea..a46055827bf 100644
--- a/reactos/lib/sdk/crt/crt.cmake
+++ b/reactos/lib/sdk/crt/crt.cmake
@@ -256,6 +256,7 @@ list(APPEND CRT_SOURCE
     string/is_wctype.c
     string/itoa.c
     string/itow.c
+    string/mbstowcs_s.c
     string/scanf.c
     string/splitp.c
     string/strcoll.c
diff --git a/reactos/lib/sdk/crt/string/mbstowcs_s.c b/reactos/lib/sdk/crt/string/mbstowcs_s.c
new file mode 100644
index 00000000000..6442cd1aae6
--- /dev/null
+++ b/reactos/lib/sdk/crt/string/mbstowcs_s.c
@@ -0,0 +1,117 @@
+/*
+ * COPYRIGHT:         See COPYING in the top level directory
+ * PROJECT:           ReactOS CRT
+ * PURPOSE:           Implementation of mbstowcs_s
+ * FILE:              lib/sdk/crt/stdlib/mbstowcs_s.c
+ * PROGRAMMER:        Timo Kreuzer
+ */
+
+#include <precomp.h>
+#include <specstrings.h>
+
+#define _mbsnlen strnlen
+
+_CRTIMP
+_Check_return_opt_
+errno_t
+__cdecl
+mbstowcs_s(
+   _Out_opt_ size_t *pReturnValue,
+   _Out_writes_to_opt_(sizeInWords, *pReturnValue) wchar_t *pwcstr,
+   _In_ size_t sizeInWords,
+   _In_reads_or_z_(count) const char *pmbstr,
+   _In_ size_t count)
+{
+    size_t cchMax, cwcWritten;
+    errno_t retval = 0;
+
+    /* Make sure, either we have a target buffer > 0 bytes, or no buffer */
+    if (!MSVCRT_CHECK_PMT( ((sizeInWords != 0) && (pwcstr != 0)) ||
+                           ((sizeInWords == 0) && (pwcstr == 0)) ))
+    {
+        _set_errno(EINVAL);
+        return EINVAL;
+    }
+
+    /* Check if we have a return value pointer */
+    if (pReturnValue)
+    {
+        /* Default to 0 bytes written */
+        *pReturnValue = 0;
+    }
+
+    if (!MSVCRT_CHECK_PMT((count == 0) || (pmbstr != 0)))
+    {
+        _set_errno(EINVAL);
+        return EINVAL;
+    }
+
+    /* Check if there is anything to do */
+    if ((pwcstr == 0) && (pmbstr == 0))
+    {
+        _set_errno(EINVAL);
+        return EINVAL;
+    }
+
+    /* Check if we have a multibyte string */
+    if (pmbstr)
+    {
+        /* Check if we also have a wchar buffer */
+        if (pwcstr)
+        {
+            /* Calculate the maximum the we can write */
+            cchMax = (count < sizeInWords) ? count + 1 : sizeInWords;
+
+            /* Now do the conversion */
+            cwcWritten = mbstowcs(pwcstr, pmbstr, cchMax);
+
+            /* Check if the buffer was not zero terminated */
+            if (cwcWritten == cchMax)
+            {
+                /* Check if we reached the max size of the dest buffer */
+                if (cwcWritten == sizeInWords)
+                {
+                    /* Does the caller allow this? */
+                    if (count != _TRUNCATE)
+                    {
+                        /* Not allowed, truncate to 0 length */
+                        pwcstr[0] = L'\0';
+
+                        /* Return error */
+                        _set_errno(ERANGE);
+                        return ERANGE;
+                    }
+
+                    /* Inform the caller about truncation */
+                    retval = STRUNCATE;
+                }
+
+                /* zero teminate the buffer */
+                pwcstr[cwcWritten - 1] = L'\0';
+            }
+            else
+            {
+                /* The buffer is zero terminated, count the terminating char */
+                cwcWritten++;
+            }
+        }
+        else
+        {
+            /* Get the length of the string, plus 0 terminator */
+            cwcWritten = _mbsnlen(pmbstr, count) + 1;
+        }
+    }
+    else
+    {
+        cwcWritten = count + 1;
+    }
+
+    /* Check if we have a return value pointer */
+    if (pReturnValue)
+    {
+        /* Default to 0 bytes written */
+        *pReturnValue = cwcWritten;
+    }
+
+    return retval;
+}