Should URL args be concatenated?

Hi all:

I am implementing basic charting for my tracker. It uses the results
of an index page and plots a pie (or bar in my version) graph by the
first group parameter.  The description is at:
https://wiki.roundup-tracker.org/QueryResultPieCharts

I am now working on drilldown. Assume you sorted a search by status.
The chart has a slice called New. You can click on the New status
slice and get an index page that is the subset of the original index
with a status of new.

To do this I append:

  &@filter=status&status=new

to the URL. This works only if the URL has a filter with only one item
in it. So if the original url has:

   @filter=queue

appending my info produces a URL like:

  @filter=queue,status

however if I start with a filter like:

  @filter=queue,nosy

my appended @filter=status seems to be dropped. The resulting URL has:

  @filter=queue,nosy

At least that is what it looks like is happening.

Has anybody else seen this?

If I am correct, I claim the expected result when adding another
@filter to the url should result in the filter being modified to:

   @filter=queue,nosy,status

Correct?

Any ideas here?

--
				-- rouilj
John Rouillard
===========================================================================
My employers don't acknowledge my existence much less my opinions.