[pmwiki-users] blank line at start of html output

[John Rankin]

One of Wikipublisher's users (PublishPDF recipe) has reported that a
couple of other recipes he uses are causing a problem. Specifically,
includeurl and backup_pmwiki (the backup pages script, I think) cause
pmwiki to emit a newline at the start of the output. As a result,
wikipublisher's <?xml ... ?> statement becomes line 2, following an empty
line 1. This causes wikipublisher's xsltproc transformation to fail,
because the input is not a valid xml document.

I can see a blank first line in the regular html output too, so it's not
an artefact of wikipublisher's output.

I am unable to figure out where pmwiki inserts this blank first line and
how to prevent it. Any help would be appreciated.

TIA
-- 
John Rankin