[xml] Trying to serialize compressed XML document

[ÐÑÐÑ ÐÑÐÑ <goblin193p mail ru>]

Hello,

I'm using libxml2-2.7.8 compiled on Windows with zlib support. 
I'm trying to get a buffer with compressed XML document. I'm using xmlSetDocCompressMode(doc, 9); function. If I save the doc to a file using xmlSaveFormatFile(), it saves the compressed file fine. 
However when I'm trying to use xmlDocDump...() functions, the buffer is not compressed. I can see that there is xmlSaveFileTo() function, however I can't find any related documentation on this matter. All my attempts cause crashes.

A code example would be much appreciated.