Crash in v0.10.1-249-gc936540

[rustyrussell]

Issue and Steps to Reproduce

Attempting to prepare a db_stmt outside of a transaction: wallet/wallet.c:2935
lightningd: FATAL SIGNAL 6 (version v0.10.1-249-gc936540-modded)
0x55e2bc7863af send_backtrace
	common/daemon.c:33
0x55e2bc786455 crashdump
	common/daemon.c:46
0x7fd8dd4d803f ???
	???:0
0x7fd8dd4d7fb7 ???
	???:0
0x7fd8dd4d9920 ???
	???:0
0x55e2bc72cdbf fatal
	lightningd/log.c:804
0x55e2bc760099 db_prepare_v2_
	wallet/db.c:794
0x55e2bc76e43a wallet_payment_store
	wallet/wallet.c:2918
0x55e2bc73bf75 payment_store
	lightningd/pay.c:514
0x55e2bc73c3d3 payment_failed
	lightningd/pay.c:627
0x55e2bc74883a fail_out_htlc
	lightningd/peer_htlcs.c:289
0x55e2bc749056 destroy_hout_subd_died
	lightningd/peer_htlcs.c:527
0x55e2bc7f33eb notify
	ccan/ccan/tal/tal.c:240
0x55e2bc7f38da del_tree
	ccan/ccan/tal/tal.c:402
0x55e2bc7f392c del_tree
	ccan/ccan/tal/tal.c:412
0x55e2bc7f392c del_tree
	ccan/ccan/tal/tal.c:412
0x55e2bc7f3c66 tal_free
	ccan/ccan/tal/tal.c:486
0x55e2bc7e3d26 io_close
	ccan/ccan/io/io.c:450
0x55e2bc7e3b5d do_plan
	ccan/ccan/io/io.c:401
0x55e2bc7e3bc6 io_ready
	ccan/ccan/io/io.c:417
0x55e2bc7e5d8c io_loop
	ccan/ccan/io/poll.c:445
0x55e2bc7244c7 io_loop_with_timers
	lightningd/io_loop_with_timers.c:21
0x55e2bc72a1fa main
	lightningd/lightningd.c:1112
0x7fd8dd4babf6 ???
	???:0
0x55e2bc700709 ???
	???:0
0xffffffffffffffff ???
	???:0
Log dumped in crash.log.20211027015325

[cdecker]

Seems like the the channeld subdaemons died while we were adding an HTLC, causing all dependent allocations to be freed, triggering the destructor to be called. We usually start a transaction when processing an event, however it seems in this case, going through the tal-chain we aren't.

Is there a good way to hook into the close event so we can wrap the cascade in a transaction as well? The alternative is to have a tiny wrapper around the destructor that just starts the DB transaction and commits it.