lightningd: refuse to let a peer open a channel if we have no fee estimates.

diff --git a/lightningd/chaintopology.c b/lightningd/chaintopology.c
index 05e356c6..bc5248b8 100644
--- a/lightningd/chaintopology.c
+++ b/lightningd/chaintopology.c
@@ -381,6 +381,11 @@ static void watch_for_unconfirmed_txs(struct lightningd *ld,
 /* Mutual recursion via timer. */
 static void next_updatefee_timer(struct chain_topology *topo);
 
+bool unknown_feerates(const struct chain_topology *topo)
+{
+	return tal_count(topo->feerates[0]) == 0;
+}
+
 static u32 interp_feerate(const struct feerate_est *rates, u32 blockcount)
 {
 	const struct feerate_est *before = NULL, *after = NULL;
diff --git a/lightningd/chaintopology.h b/lightningd/chaintopology.h
index 451113cd..9a69f34c 100644
--- a/lightningd/chaintopology.h
+++ b/lightningd/chaintopology.h
@@ -186,6 +186,9 @@ u32 smoothed_feerate_for_deadline(const struct chain_topology *topo, u32 blockco
 /* Get feerate to hit this *block number*. */
 u32 feerate_for_target(const struct chain_topology *topo, u64 deadline);
 
+/* Has our feerate estimation failed altogether? */
+bool unknown_feerates(const struct chain_topology *topo);
+
 /* Get range of feerates to insist other side abide by for normal channels.
  * If we have to guess, sets *unknown to true, otherwise false. */
 u32 feerate_min(struct lightningd *ld, bool *unknown);
diff --git a/lightningd/dual_open_control.c b/lightningd/dual_open_control.c
index f5f63b7b..628b9c90 100644
--- a/lightningd/dual_open_control.c
+++ b/lightningd/dual_open_control.c
@@ -2081,6 +2081,15 @@ static void accepter_got_offer(struct subd *dualopend,
 		return;
 	}
 
+	/* Don't allow opening if we don't know any fees; even if
+	 * ignore-feerates is set. */
+	if (unknown_feerates(dualopend->ld->topology)) {
+		subd_send_msg(dualopend,
+			      take(towire_dualopend_fail(NULL, "Cannot accept channel: feerates unknown")));
+		tal_free(payload);
+		return;
+	}
+
 	/* As a convenience to the plugin, we provide our current known
 	 * min + max feerates. Ideally, the plugin will fail to
 	 * contribute funds if the peer's feerate range is outside of
diff --git a/lightningd/opening_control.c b/lightningd/opening_control.c
index 9263ae6c..d7998197 100644
--- a/lightningd/opening_control.c
+++ b/lightningd/opening_control.c
@@ -872,6 +872,16 @@ static void opening_got_offer(struct subd *openingd,
 		return;
 	}
 
+	/* Don't allow opening if we don't know any fees; even if
+	 * ignore-feerates is set. */
+	if (unknown_feerates(openingd->ld->topology)) {
+		subd_send_msg(openingd,
+			      take(towire_openingd_got_offer_reply(NULL, "Cannot accept channel: feerates unknown",
+								   NULL, NULL, NULL, 0)));
+		tal_free(payload);
+		return;
+	}
+
 	tal_add_destructor2(openingd, openchannel_payload_remove_openingd, payload);
 	plugin_hook_call_openchannel(openingd->ld, NULL, payload);
 }
diff --git a/tests/test_connection.py b/tests/test_connection.py
index 87ee2b66..db51651c 100644
--- a/tests/test_connection.py
+++ b/tests/test_connection.py
@@ -2884,7 +2884,8 @@ def test_fundee_node_unconfirmed(node_factory, bitcoind):
 
 
 def test_no_fee_estimate(node_factory, bitcoind, executor):
-    l1 = node_factory.get_node(start=False, options={'dev-no-fake-fees': True})
+    l1 = node_factory.get_node(start=False, options={'dev-no-fake-fees': True},
+                               may_reconnect=True)
 
     # Fail any fee estimation requests until we allow them further down
     l1.daemon.rpcproxy.mock_rpc('estimatesmartfee', {
@@ -2892,7 +2893,7 @@ def test_no_fee_estimate(node_factory, bitcoind, executor):
     })
     l1.start()
 
-    l2 = node_factory.get_node()
+    l2 = node_factory.get_node(may_reconnect=True)
     l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
 
     # Can't fund a channel.
@@ -2929,9 +2930,19 @@ def test_no_fee_estimate(node_factory, bitcoind, executor):
         with pytest.raises(RpcError, match=r'Cannot estimate fees'):
             l1.rpc.fundchannel(l2.info['id'], 10**6, '2000perkw', minconf=0)
 
-    # But can accept incoming connections.
+    # Can accept incoming connections, can't allow incoming channels
     l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
+    with pytest.raises(RpcError, match=r'feerates unknown'):
+        l2.fundchannel(l1, 10**6)
+
+    # Re-enable fees for a moment so we can fund channel.
+    l1.set_feerates((15000, 11000, 7500, 3750), True)
     l2.fundchannel(l1, 10**6)
+    l1.daemon.rpcproxy.mock_rpc('estimatesmartfee', {
+        'error': {"errors": ["Insufficient data or no feerate found"], "blocks": 0}
+    })
+    l1.restart()
+    l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
 
     # Can do HTLCs.
     l2.pay(l1, 10**5)
@@ -2943,8 +2954,14 @@ def test_no_fee_estimate(node_factory, bitcoind, executor):
     sync_blockheight(bitcoind, [l1, l2])
 
     # Can do unilateral close.
-    l2.rpc.connect(l1.info['id'], 'localhost', l1.port)
+    l1.set_feerates((15000, 11000, 7500, 3750), True)
     l2.fundchannel(l1, 10**6)
+    l1.daemon.rpcproxy.mock_rpc('estimatesmartfee', {
+        'error': {"errors": ["Insufficient data or no feerate found"], "blocks": 0}
+    })
+    l1.restart()
+    l2.rpc.connect(l1.info['id'], 'localhost', l1.port)
+
     l2.pay(l1, 10**9 // 2)
     l1.rpc.dev_fail(l2.info['id'])
     l1.daemon.wait_for_log('Failing due to dev-fail command')
@@ -2954,18 +2971,6 @@ def test_no_fee_estimate(node_factory, bitcoind, executor):
     bitcoind.generate_block(100)
     sync_blockheight(bitcoind, [l1, l2])
 
-    # Start estimatesmartfee.
-    l1.set_feerates((15000, 11000, 7500, 3750), True)
-
-    # Can now fund a channel (as a test, use slow feerate).
-    l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
-    sync_blockheight(bitcoind, [l1])
-    l1.rpc.fundchannel(l2.info['id'], 10**6, 'slow')
-
-    # Can withdraw (use urgent feerate). `minconf` may be needed depending on
-    # the previous `fundchannel` selecting all confirmed outputs.
-    l1.rpc.withdraw(l2.rpc.newaddr('bech32')['bech32'], 'all', 'urgent', minconf=0)
-
 
 def test_opener_feerate_reconnect(node_factory, bitcoind):
     # l1 updates fees, then reconnect so l2 retransmits commitment_signed.
diff --git a/tests/test_opening.py b/tests/test_opening.py
index 39ae47e1..4954c31b 100644
--- a/tests/test_opening.py
+++ b/tests/test_opening.py
@@ -2931,7 +2931,6 @@ def test_zeroconf_withhold(node_factory, bitcoind, stay_withheld, mutual_close):
 
 @pytest.mark.openchannel('v1')
 @pytest.mark.openchannel('v2')
-@pytest.mark.xfail(strict=True)
 def test_opening_incoming_unknown_feerates(node_factory, bitcoind):
     """
     Don't allow incoming channels if we can't estimate feerates.