Why is linux-next rebased every day?

"I still don't understand.  Why is the rebasing necessary?  It is because we don't *want* to
see the intermediate states (the entire history of linux-next) when we later look back at the
history of trunk?"

Yes.  Though it'd also make the history of linux-next itself pretty complicated.  If they were
willing to add a ton of merges they could preserve all of the old versions of linux-next in
its history.  The resulting history would be very messy--e.g. you'd probably see the same
changes made multiple times in multiple places (since a new commit would be created each time
a developer revised or rebased a patch).

"If that were all that were desired, couldn't you, um, rebase just before merging it back to
trunk?"

Yeah, so linux-next would end up carrying a bunch of "meta-history" that wasn't ever submitted
to mainline.

I dunno whether it'd help or just confuse people.