[PATCH 1/2] wbemprox: Set variant type to VT_NULL if BSTR is NULL.

[Rémi Bernon]

Mafia III launcher crashes when querying video controllers after passing
the NULL __PATH value through COM marshalling.

Signed-off-by: Rémi Bernon 
---
 dlls/wbemprox/query.c       |  1 +
 dlls/wbemprox/tests/query.c | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/dlls/wbemprox/query.c b/dlls/wbemprox/query.c
index 6ac5ad5b770..ad7150e5401 100644
--- a/dlls/wbemprox/query.c
+++ b/dlls/wbemprox/query.c
@@ -962,6 +962,7 @@ static HRESULT get_system_propval( const struct view *view, UINT table_index, UI
         {
             V_VT( ret ) = VT_BSTR;
             V_BSTR( ret ) = build_path( view, table_index, result_index, name );
+            if (!V_BSTR( ret )) V_VT( ret ) = VT_NULL;
         }
         if (type) *type = CIM_STRING;
         return S_OK;
diff --git a/dlls/wbemprox/tests/query.c b/dlls/wbemprox/tests/query.c
index 74fdfaa9bc8..357b0a8b8e5 100644
--- a/dlls/wbemprox/tests/query.c
+++ b/dlls/wbemprox/tests/query.c
@@ -1414,6 +1414,8 @@ static void test_Win32_VideoController( IWbemServices *services )
         hr = IEnumWbemClassObject_Next( result, 10000, 1, &obj, &count );
         if (hr != S_OK) break;

+        check_property( obj, L"__GENUS", VT_I4, CIM_SINT32 );
+        check_property( obj, L"__PATH", VT_BSTR, CIM_STRING );
         check_property( obj, L"AdapterCompatibility", VT_BSTR, CIM_STRING );
         check_property( obj, L"Availability", VT_I4, CIM_UINT16 );
         check_property( obj, L"ConfigManagerErrorCode", VT_I4, CIM_UINT32 );
@@ -1432,6 +1434,27 @@ static void test_Win32_VideoController( IWbemServices *services )
         IWbemClassObject_Release( obj );
     }

+    IEnumWbemClassObject_Release( result );
+    SysFreeString( query );
+
+    query = SysAllocString( L"SELECT AdapterRAM FROM Win32_VideoController" );
+    hr = IWbemServices_ExecQuery( services, wql, query, 0, NULL, &result );
+    if (hr != S_OK)
+    {
+        win_skip( "Win32_VideoController not available\n" );
+        return;
+    }
+
+    for (;;)
+    {
+        hr = IEnumWbemClassObject_Next( result, 10000, 1, &obj, &count );
+        if (hr != S_OK) break;
+        check_property( obj, L"__GENUS", VT_I4, CIM_SINT32 );
+        check_property( obj, L"__PATH", VT_NULL, CIM_STRING );
+        check_property( obj, L"AdapterRAM", VT_I4, CIM_UINT32 );
+        IWbemClassObject_Release( obj );
+    }
+
     IEnumWbemClassObject_Release( result );
     SysFreeString( query );
     SysFreeString( wql );