From db145f575bf0ffd7936c677c7a31a2fdbdef6c1a Mon Sep 17 00:00:00 2001
From: trueptolemy <trueptolemy@foxmail.com>
Date: Tue, 27 Aug 2019 02:31:25 +0800
Subject: [PATCH] Fix: fundee can forget channel if it receives error during
 CHANNELD_AWAITING_LOCKIN

---
 lightningd/channel.c      | 29 ++++++++++++++++++++++++++++-
 lightningd/channel.h      |  3 +++
 lightningd/peer_control.c | 15 ++++++++++++---
 3 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/lightningd/channel.c b/lightningd/channel.c
index 34c87779c..69c08b1f7 100644
--- a/lightningd/channel.c
+++ b/lightningd/channel.c
@@ -362,7 +362,7 @@ void channel_fail_permanent(struct channel *channel, const char *fmt, ...)
 	struct channel_id cid;
 
 	va_start(ap, fmt);
-	why = tal_vfmt(channel, fmt, ap);
+	why = tal_vfmt(tmpctx, fmt, ap);
 	va_end(ap);
 
 	log_unusual(channel->log, "Peer permanent failure in %s: %s",
@@ -386,6 +386,33 @@ void channel_fail_permanent(struct channel *channel, const char *fmt, ...)
 	tal_free(why);
 }
 
+void channel_fail_forget(struct channel *channel, const char *fmt, ...)
+{
+	va_list ap;
+	char *why;
+	struct channel_id cid;
+
+	assert(channel->funder == REMOTE &&
+	       channel->state == CHANNELD_AWAITING_LOCKIN);
+	va_start(ap, fmt);
+	why = tal_vfmt(tmpctx, fmt, ap);
+	va_end(ap);
+
+	log_unusual(channel->log, "Peer permanent failure in %s: %s, "
+		    "forget channel",
+		    channel_state_name(channel), why);
+
+	if (!channel->error) {
+		derive_channel_id(&cid,
+				  &channel->funding_txid,
+				  channel->funding_outnum);
+		channel->error = towire_errorfmt(channel, &cid, "%s", why);
+	}
+
+	delete_channel(channel);
+	tal_free(why);
+}
+
 void channel_internal_error(struct channel *channel, const char *fmt, ...)
 {
 	va_list ap;
diff --git a/lightningd/channel.h b/lightningd/channel.h
index f1dc8f6b7..bc609e77b 100644
--- a/lightningd/channel.h
+++ b/lightningd/channel.h
@@ -187,6 +187,9 @@ PRINTF_FMT(2,3) void channel_fail_reconnect_later(struct channel *channel,
 
 /* Channel has failed, give up on it. */
 void channel_fail_permanent(struct channel *channel, const char *fmt, ...);
+/* Forget the channel. This is only used for the case when we "receive" error
+ * during CHANNELD_AWAITING_LOCKIN if we are "fundee". */
+void channel_fail_forget(struct channel *channel, const char *fmt, ...);
 /* Permanent error, but due to internal problems, not peer. */
 void channel_internal_error(struct channel *channel, const char *fmt, ...);
 
diff --git a/lightningd/peer_control.c b/lightningd/peer_control.c
index 03977275e..d14b1d910 100644
--- a/lightningd/peer_control.c
+++ b/lightningd/peer_control.c
@@ -441,9 +441,18 @@ void channel_errmsg(struct channel *channel,
 	 *    - MUST fail the channel referred to by the error message,
 	 *      if that channel is with the sending node.
 	 */
-	channel_fail_permanent(channel, "%s: %s ERROR %s",
-			       channel->owner->name,
-			       err_for_them ? "sent" : "received", desc);
+
+	/* We should immediately forget the channel if we receive error during
+	 * CHANNELD_AWAITING_LOCKIN if we are fundee. */
+	if (!err_for_them && channel->funder == REMOTE
+	    && channel->state == CHANNELD_AWAITING_LOCKIN)
+		channel_fail_forget(channel, "%s: %s ERROR %s",
+				    channel->owner->name,
+				    err_for_them ? "sent" : "received", desc);
+	else
+		channel_fail_permanent(channel, "%s: %s ERROR %s",
+				       channel->owner->name,
+				       err_for_them ? "sent" : "received", desc);
 }
 
 struct peer_connected_hook_payload {