Force an agent download

Force an agent download

[Harry Putnam]

I think we need a sure fire way to force a message to be downloaded. 
Where agent downloads a message regardless of what it thinks it knows
and even if it means overwriting the same file number.

I have encountered a situation on enough occasions to be a pita where
agent does not download a message when marked with %.  These
situations are usually like this.

For one reason or another (agent category, running plugged etc) a
message is not downloaded to disc.  Later, noticing that I want to see
this message.  Even though gnus thinks its read, I want to force the
agent to download it.  Sometimes that is no more than going plugged,
finding the message and marking it with % then running J s or J u to
grab it.  Other times that doesn't work.  I'm not really sure what the
difference is.  

I don't really know the full mechanism involved so can't specify where
it goes wrong.  However, there should be a command or way to force
agent to download a specific message and not listen to anything else.

Maybe that power can be given to `%'.  Currently that is not the case.
Gnus keeps several records of what agent sees and does.  There is 
.agentview .overview  ~/News/agent/nntp/NNTPSERVER/agent.lib/active
~/News/agent/nntp/NNTPSERVER/agent.lib/history, and finally
~/.newsrc. 

All keeping tabs on things that effect the agent.  Maybe even stuff in
.newsrc.eld involved.  How can a user cleanly override all this and
make the agent download a message (assuming its available on the server)?