Hi Alistair,
On 17.04.2017 05:43, Alistair Leslie-Hughes wrote:
diff --git a/dlls/oleaut32/variant.c b/dlls/oleaut32/variant.c index 17f753af70..6f695c3f37 100644 --- a/dlls/oleaut32/variant.c +++ b/dlls/oleaut32/variant.c @@ -2611,6 +2611,13 @@ HRESULT WINAPI VarCat(LPVARIANT left, LPVARIANT right, LPVARIANT out) V_VT(&bstrvar_left) = VT_BSTR; V_BSTR(&bstrvar_left) = SysAllocString(sz_empty); }
else if (rightvt == VT_DISPATCH){/* The returned Dispatch Value, may not be able to be coerced, ie. VT_NULL */hres = VariantChangeTypeEx(&bstrvar_left,left,0,0,VT_BSTR);if (hres != S_OK && hres != DISP_E_TYPEMISMATCH)return hres;} else { hres = VariantChangeTypeEx(&bstrvar_left,left,0,0,VT_BSTR);@@ -2651,6 +2658,13 @@ HRESULT WINAPI VarCat(LPVARIANT left, LPVARIANT right, LPVARIANT out) V_VT(&bstrvar_right) = VT_BSTR; V_BSTR(&bstrvar_right) = SysAllocString(sz_empty); }
else if (rightvt == VT_DISPATCH){/* The returned Dispatch Value, may not be able to be coerced, ie. VT_NULL */hres = VariantChangeTypeEx(&bstrvar_right,right,0,0,VT_BSTR);if (hres != S_OK && hres != DISP_E_TYPEMISMATCH)return hres;} else { hres = VariantChangeTypeEx(&bstrvar_right,right,0,0,VT_BSTR);
While this change may do the right thing in the case you're fixing, the whole surrounding code looks just wrong and I don't like the idea of making it even more complicated to work around problem in this single case. For example take a look at if() statement in line 2620. It's never executed, because it requires leftvt to be VT_NULL, which is handled elsewhere (line 2609). If you remove that if(), this call is almost identical to what you add here as a special case. The only difference is DISP_E_TYPEMISMATCH handling. Did you investigate what happens in such case? Maybe we should handle VariantChangeTypeEx failures like you do in the patch?
Thanks, Jacek
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Jacek Caban