[PATCH 2/2] oledb32: GetConversionSize shouldn't fail for null variants.

[Alistair Leslie-Hughes]

If we have a NULL variant which will be converted to a non-fixed
sized type (DBTYPE_WSTR) then we just return S_OK.

Signed-off-by: Alistair Leslie-Hughes <leslie_alistair at hotmail.com>
---
 dlls/oledb32/convert.c       |  3 +++
 dlls/oledb32/tests/convert.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/dlls/oledb32/convert.c b/dlls/oledb32/convert.c
index a87cf18..2c05099 100644
--- a/dlls/oledb32/convert.c
+++ b/dlls/oledb32/convert.c
@@ -1344,6 +1344,9 @@ static HRESULT WINAPI convert_GetConversionSize(IDataConvert* iface,
     if ((*dst_len = get_length(dst_type)))
         return S_OK;
 
+    if(src_type == DBTYPE_VARIANT && V_VT((VARIANT*)src) == VT_NULL)
+        return S_OK;
+
     switch (dst_type)
     {
     case DBTYPE_STR:
diff --git a/dlls/oledb32/tests/convert.c b/dlls/oledb32/tests/convert.c
index a785457..55539f9 100644
--- a/dlls/oledb32/tests/convert.c
+++ b/dlls/oledb32/tests/convert.c
@@ -2627,6 +2627,33 @@ static void test_getconversionsize(void)
     ok(hr == S_OK, "got 0x%08x\n", hr);
     VariantClear(&var);
 
+    dst_len = 78;
+    V_VT(&var) = VT_NULL;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_VARIANT, DBTYPE_WSTR, NULL, &dst_len, &var);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+
+    dst_len = 0;
+    src_len = 20;
+    V_VT(&var) = VT_BSTR;
+    V_BSTR(&var) = SysAllocString(strW);
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_VARIANT, DBTYPE_STR, &src_len, &dst_len, &var);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+    ok(dst_len == 5, "%ld\n", dst_len);
+    VariantClear(&var);
+
+    dst_len = 0;
+    src_len = 20;
+    V_VT(&var) = VT_I4;
+    V_I4(&var) = 4;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_VARIANT, DBTYPE_STR, &src_len, &dst_len, &var);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+    VariantClear(&var);
+
+    dst_len = 78;
+    V_VT(&var) = VT_NULL;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_VARIANT, DBTYPE_STR, NULL, &dst_len, &var);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
+
     dst_len = 0;
     src_len = 20;
     V_VT(&var) = VT_BSTR;
@@ -2655,6 +2682,12 @@ static void test_getconversionsize(void)
     ok(hr == S_OK, "got 0x%08x\n", hr);
     ok(dst_len == 1802, "%ld\n", dst_len);
     VariantClear(&var);
+
+    dst_len = 32;
+    V_VT(&var) = VT_NULL;
+    hr = IDataConvert_GetConversionSize(convert, DBTYPE_VARIANT, DBTYPE_I4, NULL, &dst_len, &var);
+    ok(dst_len == 4, "%ld\n", dst_len);
+    ok(hr == S_OK, "got 0x%08x\n", hr);
 }
 
 static void test_converttobytes(void)
-- 
1.9.1