dlls/msxml3: Using strlenW instead of SysStringLen to check node name length

[Dan Kegel]

Hi Eric,
welcome to Wine!
http://msdn.microsoft.com/en-us/library/ms221240.aspx
says the only time those two functions disagree on valid bstr's
is if there are embedded nul chars, in which case SysStringLength
probably returns a larger value.  Are you quite, quite sure that
your bstrs are valid?
(In general, the best way to answer questions like that
is to add a test case to your patch, and make sure it
passes on Windows as well as Wine before submitting
to wine-patches.)
- Dan