[josm-dev] "area too big"

[David Earl]

I got an "area too big" message doing "Update data" in JOSM on the 
eighth of eight areas in the file (or at least, it was at the end - 
maybe the message applied to one of the intermediate ones, but if so it 
didn't say so until the end). Presumably the density of nodes in that 
area has gone over the top since I first downloaded the data which I am 
updating.

A few questions:

(a) is the problem the last area; if not, how do I find out which it is? 
(or is it in some way the sum total of all 8 of the requests it is 
blowing up on).

(b) has it downloaded and incorporated the earlier seven that appeared 
to succeed? Or did it revert back entirely to my original data?

(c) if I get this from a planet file instead getting osmosis to extract 
the area, can JOSM open the result (subject to memory etc, as it is a 
large-ish file - I'm thinking of format rather than size).

Thanks,
David