1. amount operations should force you to check validity, rather than
needing a separate call, so make amount_msat_to_u32 return bool,
and WARN_UNUSED_RESULT it.
2. Create a special parsing function for this; not only does this mean
we now only need that one amount call, but also 'check' will correctly
fail with invalid amounts (it only does the parsing step).
3. If we create a primitive which we immediately take(), we allocate it
off NULL to make it clear we expect its lifetime to end here.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I tried to fundchannel 0.01btc, and of course it wanted 8 decimals exactly.
If I can't get this right, it's probably a bad idea.
I still don't allow whole number of btc though, since that's probably a mistake
and you're not supposed to put that much in c-lightning yet :)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
They're generally used pass-by-copy (unusual for C structs, but
convenient they're basically u64) and all possibly problematic
operations return WARN_UNUSED_RESULT bool to make you handle the
over/underflow cases.
The new #include in json.h means we bolt11.c sees the amount.h definition
of MSAT_PER_BTC, so delete its local version.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
