From d7c06b5b0e888a30d0b448418bc1473fe1805705 Mon Sep 17 00:00:00 2001
From: niftynei <niftynei@gmail.com>
Date: Thu, 22 Oct 2020 14:23:45 -0500
Subject: [PATCH] mfc-df: once we've gotten the PSBT finalized, we wait for
 peer sigs

We need our peer's signatures to arrive before we sign/broadcast the
funding transaction (but only if there's v2 peers present)
---
 plugins/spender/multifundchannel.c | 19 +++++++++++++------
 plugins/spender/openchannel.c      |  8 +++++---
 plugins/spender/openchannel.h      |  3 +++
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/plugins/spender/multifundchannel.c b/plugins/spender/multifundchannel.c
index 88eb7be09..3d58ac789 100644
--- a/plugins/spender/multifundchannel.c
+++ b/plugins/spender/multifundchannel.c
@@ -1340,10 +1340,12 @@ perform_fundchannel_complete(struct multifundchannel_command *mfc)
 		   "mfc %"PRIu64": parallel fundchannel_complete.",
 		   mfc->id);
 
-	mfc->pending = tal_count(mfc->destinations);
+	mfc->pending = dest_count(mfc, FUND_CHANNEL);
 
-	for (i = 0; i < tal_count(mfc->destinations); ++i)
-		fundchannel_complete_dest(&mfc->destinations[i]);
+	for (i = 0; i < tal_count(mfc->destinations); ++i) {
+		if (mfc->destinations[i].protocol == FUND_CHANNEL)
+			fundchannel_complete_dest(&mfc->destinations[i]);
+	}
 
 	assert(mfc->pending != 0);
 	return command_still_pending(mfc->cmd);
@@ -1466,7 +1468,7 @@ fundchannel_complete_done(struct multifundchannel_destination *dest)
 }
 
 static struct command_result *
-perform_sendpsbt(struct multifundchannel_command *mfc);
+perform_signpsbt(struct multifundchannel_command *mfc);
 
 static struct command_result *
 after_fundchannel_complete(struct multifundchannel_command *mfc)
@@ -1482,6 +1484,8 @@ after_fundchannel_complete(struct multifundchannel_command *mfc)
 		struct multifundchannel_destination *dest;
 
 		dest = &mfc->destinations[i];
+		if (dest->protocol != FUND_CHANNEL)
+			continue;
 
 		assert(dest->state == MULTIFUNDCHANNEL_COMPLETED
 		    || dest->state == MULTIFUNDCHANNEL_FAILED);
@@ -1493,7 +1497,10 @@ after_fundchannel_complete(struct multifundchannel_command *mfc)
 		return redo_multifundchannel(mfc, "fundchannel_complete");
 	}
 
-	return perform_sendpsbt(mfc);
+	if (dest_count(mfc, OPEN_CHANNEL) > 0)
+		return check_sigs_ready(mfc);
+
+	return perform_signpsbt(mfc);
 }
 
 /*---------------------------------------------------------------------------*/
@@ -1509,7 +1516,7 @@ after_signpsbt(struct command *cmd,
 	       struct multifundchannel_command *mfc);
 
 static struct command_result *
-perform_sendpsbt(struct multifundchannel_command *mfc)
+perform_signpsbt(struct multifundchannel_command *mfc)
 {
 	struct out_req *req;
 
diff --git a/plugins/spender/openchannel.c b/plugins/spender/openchannel.c
index 0397ef116..fa7d6f067 100644
--- a/plugins/spender/openchannel.c
+++ b/plugins/spender/openchannel.c
@@ -583,8 +583,8 @@ collect_sigs(struct multifundchannel_command *mfc)
 	return send_outreq(mfc->cmd->plugin, req);
 }
 
-static void
-openchannel_dest_signed(struct multifundchannel_command *mfc)
+struct command_result *
+check_sigs_ready(struct multifundchannel_command *mfc)
 {
 	bool ready = true;
 	for (size_t i = 0; i < tal_count(mfc->destinations); i++)
@@ -593,6 +593,8 @@ openchannel_dest_signed(struct multifundchannel_command *mfc)
 
 	if (ready)
 		collect_sigs(mfc);
+
+	return command_still_pending(mfc->cmd);
 }
 
 static void json_peer_sigs(struct command *cmd,
@@ -667,7 +669,7 @@ static void json_peer_sigs(struct command *cmd,
 
 	tal_wally_end(dest->mfc->psbt);
 	dest->state = MULTIFUNDCHANNEL_SIGNED;
-	openchannel_dest_signed(dest->mfc);
+	check_sigs_ready(dest->mfc);
 }
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*
diff --git a/plugins/spender/openchannel.h b/plugins/spender/openchannel.h
index 756589d19..a6191ff33 100644
--- a/plugins/spender/openchannel.h
+++ b/plugins/spender/openchannel.h
@@ -21,4 +21,7 @@ void openchannel_init(struct plugin *p, const char *b,
 struct command_result *
 perform_openchannel_update(struct multifundchannel_command *mfc);
 
+struct command_result *
+check_sigs_ready(struct multifundchannel_command *mfc);
+
 #endif /* LIGHTNING_PLUGINS_SPENDER_OPENCHANNEL_H */