oledb32: Implement GetConversionSize DBTYPE_WSTR->DBTYPE_WSTR.

dlls/oledb32/convert.c

@@ -1095,6 +1095,22 @@ static HRESULT WINAPI convert_GetConversionSize(IDataConvert* iface,
         }
     }
     break;
+    case DBTYPE_WSTR:
+    {
+        switch (src_type)
+        {
+        case DBTYPE_WSTR:
+            if(src_len)
+                *dst_len = (*src_len) + sizeof(WCHAR);
+            else
+                *dst_len = (lstrlenW(src) + 1) * sizeof(WCHAR);
+            break;
+        default:
+            FIXME("unimplemented for %04x -> DBTYPE_WSTR\n", src_type);
+            return E_NOTIMPL;
+        }
+    }
+    break;
     default:
         FIXME("unimplemented for conversion %d->%d\n", src_type, dst_type);
         return E_NOTIMPL;

dlls/oledb32/tests/convert.c

@@ -2480,8 +2480,10 @@ static void test_getconversionsize(void)
 {
     IDataConvert *convert;
     DBLENGTH dst_len;
+    DBLENGTH src_len;
     HRESULT hr;
     BSTR str;
+    static WCHAR strW[] = {'t','e','s','t',0};
 
     hr = CoCreateInstance(&CLSID_OLEDB_CONVERSIONLIBRARY, NULL, CLSCTX_INPROC_SERVER, &IID_IDataConvert, (void**)&convert);
     if(FAILED(hr))
@@ -2511,6 +2513,23 @@ static void test_getconversionsize(void)
     ok(dst_len == sizeof(VARIANT), "%ld\n", dst_len);
     SysFreeString(str);
 
+    dst_len = 0;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_WSTR, DBTYPE_WSTR, NULL, &dst_len, strW);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+    ok(dst_len == 10, "%ld\n", dst_len);
+
+    dst_len = 0;
+    src_len = 2;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_WSTR, DBTYPE_WSTR, &src_len, &dst_len, strW);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+    ok(dst_len == 4, "%ld\n", dst_len);
+
+    dst_len = 0;
+    src_len = 20;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_WSTR, DBTYPE_WSTR, &src_len, &dst_len, strW);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+    ok(dst_len == 22, "%ld\n", dst_len);
+
     IDataConvert_Release(convert);
 }