bookkeeper: keep up with new entries if we're doing currency conversion.

diff --git a/plugins/bkpr/bookkeeper.c b/plugins/bkpr/bookkeeper.c
index fcab7a0a..10413756 100644
--- a/plugins/bkpr/bookkeeper.c
+++ b/plugins/bkpr/bookkeeper.c
@@ -1633,6 +1633,64 @@ static void memleak_scan_currencyrates(struct htable *memtable,
 	memleak_scan_uintmap(memtable, currency_rates);
 }
 
+/* Whenever wait says the chainmoves or channelmoves fires, we refresh */
+
+/* Mutual recursion */
+static struct command_result *
+currency_chainmoves_wait(struct command *auxcmd, void *unused);
+static struct command_result *
+currency_channelmoves_wait(struct command *auxcmd, void *unused);
+
+static struct command_result *
+currency_chainmoves_wait_done(struct command *auxcmd,
+			      const char *methodname,
+			      const char *buf,
+			      const jsmntok_t *result,
+			      void *unused)
+{
+	return refresh_moves(auxcmd, currency_chainmoves_wait, NULL);
+}
+
+static struct command_result *
+currency_channelmoves_wait_done(struct command *auxcmd,
+				const char *methodname,
+				const char *buf,
+				const jsmntok_t *result,
+				void *unused)
+{
+	return refresh_moves(auxcmd, currency_channelmoves_wait, NULL);
+}
+
+static struct command_result *
+currency_chainmoves_wait(struct command *auxcmd, void *unused)
+{
+	struct bkpr *bkpr = bkpr_of(auxcmd->plugin);
+	struct out_req *req;
+	req = jsonrpc_request_start(auxcmd, "wait",
+				    currency_chainmoves_wait_done,
+				    plugin_broken_cb,
+				    NULL);
+	json_add_string(req->js, "subsystem", "chainmoves");
+	json_add_string(req->js, "indexname", "created");
+	json_add_u64(req->js, "nextvalue", bkpr->chainmoves_index+1);
+	return send_outreq(req);
+}
+
+static struct command_result *
+currency_channelmoves_wait(struct command *auxcmd, void *unused)
+{
+	struct bkpr *bkpr = bkpr_of(auxcmd->plugin);
+	struct out_req *req;
+	req = jsonrpc_request_start(auxcmd, "wait",
+				    currency_channelmoves_wait_done,
+				    plugin_broken_cb,
+				    NULL);
+	json_add_string(req->js, "subsystem", "channelmoves");
+	json_add_string(req->js, "indexname", "created");
+	json_add_u64(req->js, "nextvalue", bkpr->channelmoves_index+1);
+	return send_outreq(req);
+}
+
 static const char *init(struct command *init_cmd, const char *b, const jsmntok_t *t)
 {
 	struct plugin *p = init_cmd->plugin;
@@ -1660,6 +1718,14 @@ static const char *init(struct command *init_cmd, const char *b, const jsmntok_t
 	} else
 		bkpr->chainmoves_index = 0;
 
+	/* If we're supposed to do currency conversions, we refresh
+	 * all the time. */
+	if (bkpr->currency) {
+		struct command *auxcmd = aux_command(init_cmd);
+		currency_chainmoves_wait(auxcmd, NULL);
+		currency_channelmoves_wait(auxcmd, NULL);
+	}
+
 	return NULL;
 }
 
diff --git a/tests/test_currencyrate.py b/tests/test_currencyrate.py
index f97664ca..2181d4e5 100644
--- a/tests/test_currencyrate.py
+++ b/tests/test_currencyrate.py
@@ -234,23 +234,28 @@ class _ServerThread(threading.Thread):
 @pytest.fixture
 def fake_rateserver():
     app = Flask(__name__)
+    state = {
+        "fast": 100_000_000,
+        "slow": 50_000_000,
+        "slow_delay": 1,
+    }
 
     @app.get("/fast")
     def fast():
-        # 1e11 / 100_000_000 = 1000 msat per USD
-        return jsonify({"price": 100_000_000})
+        return jsonify({"price": state["fast"]})
 
     @app.get("/slow")
     def slow():
-        # Make this complete later, so it becomes latest_fresh_price().
-        time.sleep(1)
-        # 1e11 / 50_000_000 = 2000 msat per USD
-        return jsonify({"price": 50_000_000})
+        time.sleep(state["slow_delay"])
+        return jsonify({"price": state["slow"]})
 
     srv = _ServerThread(app)
     srv.start()
     try:
-        yield f"http://127.0.0.1:{srv.port}"
+        yield {
+            "url": f"http://127.0.0.1:{srv.port}",
+            "state": state,
+        }
     finally:
         srv.shutdown()
         srv.join()
@@ -269,8 +274,8 @@ def test_cached_median(node_factory, fake_rateserver):
             "binance",
         ],
         "currencyrate-add-source": [
-            f"fast,{fake_rateserver}/fast,price",
-            f"slow,{fake_rateserver}/slow,price",
+            f"fast,{fake_rateserver['url']}/fast,price",
+            f"slow,{fake_rateserver['url']}/slow,price",
         ],
     }
     l1 = node_factory.get_node(options=opts)
@@ -282,11 +287,11 @@ def test_cached_median(node_factory, fake_rateserver):
     assert "fast" in rates
     assert "slow" in rates
 
-    assert rates["fast"] == 100_000_000
-    assert rates["slow"] == 50_000_000
+    assert rates["fast"] == fake_rateserver["state"]["fast"]
+    assert rates["slow"] == fake_rateserver["state"]["slow"]
 
     # Cached result should be median of two rates.
-    median_rate = (100_000_000 + 50_000_000) / 2
+    median_rate = (fake_rateserver["state"]["fast"] + fake_rateserver["state"]["slow"]) / 2
     convert = l1.rpc.call("currencyconvert", [100, "USD"])
     LOGGER.info(convert)
 
@@ -306,8 +311,8 @@ def test_bkpr_listaccountevents_currencyrate(node_factory, fake_rateserver):
             "binance",
         ],
         "currencyrate-add-source": [
-            f"fast,{fake_rateserver}/fast,price",
-            f"slow,{fake_rateserver}/slow,price",
+            f"fast,{fake_rateserver['url']}/fast,price",
+            f"slow,{fake_rateserver['url']}/slow,price",
         ],
         "bkpr-currency": "USD",
     }
@@ -322,3 +327,43 @@ def test_bkpr_listaccountevents_currencyrate(node_factory, fake_rateserver):
     median_rate = (100_000_000 + 50_000_000) / 2
     for e in events:
         assert e["currencyrate"] == median_rate
+
+
+def test_bkpr_listaccountevents_realtime(node_factory, fake_rateserver):
+    """Make sure we don't wait for bkpr command to look up rates!"""
+    opts = {
+        "currencyrate-disable-source": [
+            "bitstamp",
+            "coinbase",
+            "coingecko",
+            "kraken",
+            "blockchain.info",
+            "coindesk",
+            "binance",
+        ],
+        "currencyrate-add-source": [
+            f"fast,{fake_rateserver['url']}/fast,price",
+            f"slow,{fake_rateserver['url']}/slow,price",
+        ],
+        "bkpr-currency": "USD",
+    }
+    l1, l2 = node_factory.line_graph(2, opts=opts)
+
+    old_median = (fake_rateserver["state"]["fast"] + fake_rateserver["state"]["slow"]) / 2
+
+    inv = l2.rpc.invoice(100000, "test_bkpr_listaccountevents_realtime", "desc")
+    l1.rpc.pay(inv["bolt11"])
+    # We want this event in the list, so wait until it's totally closed.
+    wait_for(lambda: only_one(l1.rpc.listpeerchannels()['channels'])['htlcs'] == [])
+
+    # We could put a log msg inside bookkeeper, but that's spammy.
+    time.sleep(10)
+
+    # Change rates.  But old ones should be used!
+    fake_rateserver["state"]["fast"] = 200_000_000
+    fake_rateserver["state"]["slow"] = 150_000_000
+
+    events = l1.rpc.bkpr_listaccountevents()["events"]
+    assert events
+    for e in events:
+        assert e["currencyrate"] == old_median