Re: XMLDocument.save("localfile.xml") <possible solutions>

Lucky wrote:
>   if (!localFile.exists()) localFile.create(localFile.NORMAL_FILE_TYPE, 
> 0644);

This is not needed as you pass PR_CREATE_FILE (0x08) to init.

>   outputStream.init(localFile, 0x04 | 0x08 | 0x20, 0644, 0);

not sure why this uses PR_RDWR (0x04) rather than PR_WRONLY (0x02)...

As for the second variant:

>   (new XMLSerializer).serializeToStream(this, os, charset);

This doesn't work, does it? The converter output stream is not an 
nsIOutputStream...