From 960852f44780742b9bc1099a4b13222ef076cd8d Mon Sep 17 00:00:00 2001
From: Nikolay Sivov <nsivov@codeweavers.com>
Date: Sat, 6 Apr 2013 15:52:31 +0400
Subject: [PATCH] oledb32: Implement GetConversionSize for DBTYPE_VARIANT ->
 DBTYPE_STR case.

---
 dlls/oledb32/convert.c       | 54 ++++++++++++++++++++++++++++++++----
 dlls/oledb32/tests/convert.c | 30 ++++++++++++++++++++
 2 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/dlls/oledb32/convert.c b/dlls/oledb32/convert.c
index f56601bf0b7..f2c46b0dd15 100644
--- a/dlls/oledb32/convert.c
+++ b/dlls/oledb32/convert.c
@@ -996,14 +996,58 @@ static HRESULT WINAPI convert_CanConvert(IDataConvert* iface,
 }
 
 static HRESULT WINAPI convert_GetConversionSize(IDataConvert* iface,
-                                                DBTYPE wSrcType, DBTYPE wDstType,
-                                                DBLENGTH *pcbSrcLength, DBLENGTH *pcbDstLength,
-                                                void *pSrc)
+                                                DBTYPE src_type, DBTYPE dst_type,
+                                                DBLENGTH *src_len, DBLENGTH *dst_len,
+                                                void *src)
 {
     convert *This = impl_from_IDataConvert(iface);
-    FIXME("(%p)->(%d, %d, %p, %p, %p): stub\n", This, wSrcType, wDstType, pcbSrcLength, pcbDstLength, pSrc);
+    HRESULT hr;
 
-    return E_NOTIMPL;
+    TRACE("(%p)->(%d, %d, %p, %p, %p)\n", This, src_type, dst_type, src_len, dst_len, src);
+
+    hr = IDataConvert_CanConvert(iface, src_type, dst_type);
+    if (hr != S_OK)
+        return DB_E_UNSUPPORTEDCONVERSION;
+
+    if (!dst_len)
+        return E_INVALIDARG;
+
+    /* for some types we don't need to look into source data */
+    if ((*dst_len = get_length(dst_type)))
+        return S_OK;
+
+    switch (dst_type)
+    {
+    case DBTYPE_STR:
+    {
+        switch (src_type)
+        {
+        case DBTYPE_VARIANT:
+        {
+            VARIANT v;
+
+            VariantInit(&v);
+            if ((hr = VariantChangeType(&v, (VARIANT*)src, 0, VT_BSTR)) == S_OK)
+            {
+                *dst_len = WideCharToMultiByte(CP_ACP, 0, V_BSTR(&v), -1, NULL, 0, NULL, NULL);
+                VariantClear(&v);
+            }
+            else
+                return hr;
+        }
+        break;
+        default:
+            FIXME("unimplemented for %04x -> DBTYPE_STR\n", src_type);
+            return E_NOTIMPL;
+        }
+    }
+    break;
+    default:
+        FIXME("unimplemented for destination type %d\n", dst_type);
+        return E_NOTIMPL;
+    }
+
+    return S_OK;
 }
 
 static const struct IDataConvertVtbl convert_vtbl =
diff --git a/dlls/oledb32/tests/convert.c b/dlls/oledb32/tests/convert.c
index dd80fe475bf..400ea3d5042 100644
--- a/dlls/oledb32/tests/convert.c
+++ b/dlls/oledb32/tests/convert.c
@@ -2435,6 +2435,35 @@ todo_wine
     IDataConvert_Release(convert);
 }
 
+static void test_getconversionsize(void)
+{
+    IDataConvert *convert;
+    DBLENGTH dst_len;
+    HRESULT hr;
+
+    hr = CoCreateInstance(&CLSID_OLEDB_CONVERSIONLIBRARY, NULL, CLSCTX_INPROC_SERVER, &IID_IDataConvert, (void**)&convert);
+    if(FAILED(hr))
+    {
+        win_skip("Unable to load oledb conversion library\n");
+        return;
+    }
+
+    /* same way as CanConvert fails here */
+    dst_len = 0;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_NULL, DBTYPE_BSTR, NULL, &dst_len, NULL);
+    ok(hr == DB_E_UNSUPPORTEDCONVERSION, "got 0x%08x\n", hr);
+
+    dst_len = 0;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_I2, DBTYPE_I4, NULL, &dst_len, NULL);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+    ok(dst_len == 4, "got %ld\n", dst_len);
+
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_I2, DBTYPE_I4, NULL, NULL, NULL);
+    ok(hr == E_INVALIDARG, "got 0x%08x\n", hr);
+
+    IDataConvert_Release(convert);
+}
+
 START_TEST(convert)
 {
     OleInitialize(NULL);
@@ -2453,5 +2482,6 @@ START_TEST(convert)
     test_converttofiletime();
     test_converttocy();
     test_converttoui8();
+    test_getconversionsize();
     OleUninitialize();
 }