We already discard a great deal of state in (single-pass) tshark that we keep around
in Wireshark (or two-pass tshark). We do need to keep some, though.
It's only a bug if we're keeping more than we actually need, and that's
not determinable from the information we have here. Dario, if you could get us a memory profile of tshark in this situation (through valgrind's massif tool, for example) that would help us debug further.
I
dislike the idea of two-pass by default for exactly this reason: people
expect tshark to be relatively state-less. This is already not the
case, but it's a lot worse in two-pass mode. It might even make sense to
add a --state-less flag to tshark that disables all options which
require state. I don't know how feasible that would be however.
Evan