[PATCH 0/1] MR897: oleauto: dereference VT_RECORD|VT_BYREF in place

[Kevin Puetz (＠puetzk)]

VariantCopyInd allows pvargDest == pvargSrc in order to dereference in place
To avoid confusing the source values and a partially-written destination,
wine's implementation makes a shallow copy and uses that as pSrc.

However, the call to VARIANT_CopyIRecordInfo did not use this,
leading to it copying from the zeroed-out memory it just allocated.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/897

[PATCH 1/1] oleauto: dereference VT_RECORD|VT_BYREF in place

[Kevin Puetz]

From: Kevin Puetz <PuetzKevinA(a)JohnDeere.com>

VariantCopyInd allows pvargDest == pvargSrc in order to dereference in place
To avoid confusing the source values and a partially-written destination,
wine's implementation makes a shallow copy and uses that as pSrc.

However, the call to VARIANT_CopyIRecordInfo did not use this,
leading to it copying from the zeroed-out memory it just allocated.
---
 dlls/oleaut32/variant.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlls/oleaut32/variant.c b/dlls/oleaut32/variant.c
index 885082cc659..ec0c9544a61 100644
--- a/dlls/oleaut32/variant.c
+++ b/dlls/oleaut32/variant.c
@@ -879,7 +879,7 @@ HRESULT WINAPI VariantCopyInd(VARIANT* pvargDest, const VARIANTARG* pvargSrc)
   }
   else if (V_VT(pSrc) == (VT_RECORD|VT_BYREF))
   {
-    hres = VARIANT_CopyIRecordInfo(pvargDest, pvargSrc);
+    hres = VARIANT_CopyIRecordInfo(pvargDest, pSrc);
   }
   else if (V_VT(pSrc) == (VT_DISPATCH|VT_BYREF) ||
            V_VT(pSrc) == (VT_UNKNOWN|VT_BYREF))
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/897

[Huw Davies (＠huw)]

Although this looks correct, some tests would be nice.  It shouldn't be too hard to add them at the end of `test_VariantCopyInd()`, perhaps including both the `src == dst` and `src != dst` cases.  There's `get_test_recordinfo()` which should help.

Also note the commit msg prefix should be 'oleaut32:'.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/897#note_9031