msi/tests: automation: Check for NULL source string before calling lstrcpyW.

dlls/msi/tests/automation.c

@@ -684,7 +684,7 @@ static HRESULT Installer_RegistryValueW(HKEY hkey, LPCWSTR szKey, LPCWSTR szValu
     V_BSTR(&vararg) = SysAllocString(szValue);
 
     hr = Installer_RegistryValue(hkey, szKey, vararg, &varresult, VT_BSTR);
-    lstrcpyW(szString, V_BSTR(&varresult));
+    if (V_BSTR(&varresult)) lstrcpyW(szString, V_BSTR(&varresult));
     VariantClear(&varresult);
     return hr;
 }
@@ -811,7 +811,7 @@ static HRESULT Installer_VersionGet(LPWSTR szVersion)
     HRESULT hr;
 
     hr = invoke(pInstaller, "Version", DISPATCH_PROPERTYGET, &dispparams, &varresult, VT_BSTR);
-    lstrcpyW(szVersion, V_BSTR(&varresult));
+    if (V_BSTR(&varresult)) lstrcpyW(szVersion, V_BSTR(&varresult));
     VariantClear(&varresult);
     return hr;
 }
@@ -839,7 +839,7 @@ static HRESULT Session_PropertyGet(IDispatch *pSession, LPCWSTR szName, LPWSTR s
     V_BSTR(&vararg[0]) = SysAllocString(szName);
 
     hr = invoke(pSession, "Property", DISPATCH_PROPERTYGET, &dispparams, &varresult, VT_BSTR);
-    lstrcpyW(szReturn, V_BSTR(&varresult));
+    if (V_BSTR(&varresult)) lstrcpyW(szReturn, V_BSTR(&varresult));
     VariantClear(&varresult);
     return hr;
 }
@@ -1101,7 +1101,7 @@ static HRESULT Record_StringDataGet(IDispatch *pRecord, int iField, LPWSTR szStr
     V_I4(&vararg[0]) = iField;
 
     hr = invoke(pRecord, "StringData", DISPATCH_PROPERTYGET, &dispparams, &varresult, VT_BSTR);
-    lstrcpyW(szString, V_BSTR(&varresult));
+    if (V_BSTR(&varresult)) lstrcpyW(szString, V_BSTR(&varresult));
     VariantClear(&varresult);
     return hr;
 }
@@ -1169,7 +1169,7 @@ static HRESULT StringList_Item(IDispatch *pStringList, int iIndex, LPWSTR szStri
     V_I4(&vararg[0]) = iIndex;
 
     hr = invoke(pStringList, "Item", DISPATCH_PROPERTYGET, &dispparams, &varresult, VT_BSTR);
-    lstrcpyW(szString, V_BSTR(&varresult));
+    if (V_BSTR(&varresult)) lstrcpyW(szString, V_BSTR(&varresult));
     VariantClear(&varresult);
     return hr;
 }