> In some context I think you can fool Saxon by using different URIs e.g.
> append some query string to the input URI
>
>
> <xsl:variable name="current_log_content" select="document($Log_file_name ||
'?foo=bar')"/>
>

Indeed you can, but you run the risk here that the reading and writing will
actually be concurrent, which will lead to a different failure. You would need
to force the read to happen first, for example by outtputting something that
appears to depend on the input document content (for example
doc('xxx')//this-wont-find-anything) before doing the xsl:result-document.

Michael Kay
Saxonica