It's an array: we were only saving the single element; if there was more than
one changed HTLC we'd get a bad signature!
The report in #1907
is probably caused by the other side re-requesting
something we considered already finalized; to avoid this particular error,
we should set the field to NULL if there's no last_sent_commit.
I'm increasingly of the opinion we want to just save all the update
packets to the db and blast them out, instead of doing this
second-guessing dance.
Fixes: #1907
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell
cefb6925b2