listpeers: show maximum_htlc_out_msat.

This is htlc_maximum_msat in BOLT 7 speak, but this name matches our existing
fields and is clearer in this context.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

doc/lightning-listpeers.7.md

@@ -87,6 +87,7 @@ On success, an object containing **peers** is returned.  It is an array of objec
   - **spendable_msat** (msat, optional): total we could send through channel
   - **receivable_msat** (msat, optional): total peer could send through channel
   - **minimum_htlc_in_msat** (msat, optional): the minimum amount HTLC we accept
+  - **maximum_htlc_out_msat** (msat, optional): the maximum amount HTLC we will send
   - **their_to_self_delay** (u32, optional): the number of blocks before they can take their funds if they unilateral close
   - **our_to_self_delay** (u32, optional): the number of blocks before we can take our funds if we unilateral close
   - **max_accepted_htlcs** (u32, optional): Maximum number of incoming HTLC we will accept at once
@@ -378,4 +379,4 @@ Main web site: <https://github.com/ElementsProject/lightning> Lightning
 RFC site (BOLT \#9):
 <https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md>
 
-[comment]: # ( SHA256STAMP:001e3cf495571bb09fe29f74adde8a6e40e69ddb1169934924eaf901a1e5f3c0)
+[comment]: # ( SHA256STAMP:8e30caf48aed46acc7c053a355867dc8b8624035dba4ea7668d30d86b8d827cd)

doc/schemas/listpeers.schema.json

@@ -418,6 +418,10 @@
                   "type": "msat",
                   "description": "the minimum amount HTLC we accept"
                 },
+                "maximum_htlc_out_msat": {
+                  "type": "msat",
+                  "description": "the maximum amount HTLC we will send"
+                },
                 "their_to_self_delay": {
                   "type": "u32",
                   "description": "the number of blocks before they can take their funds if they unilateral close"
@@ -772,6 +776,7 @@
                       "spendable_msat": {},
                       "receivable_msat": {},
                       "minimum_htlc_in_msat": {},
+                      "maximum_htlc_out_msat": {},
                       "spendable_msatoshi": {},
                       "receivable_msatoshi": {},
                       "their_to_self_delay": {},
@@ -859,6 +864,7 @@
                       "spendable_msat": {},
                       "receivable_msat": {},
                       "minimum_htlc_in_msat": {},
+                      "maximum_htlc_out_msat": {},
                       "spendable_msatoshi": {},
                       "receivable_msatoshi": {},
                       "their_to_self_delay": {},
@@ -947,6 +953,7 @@
                       "spendable_msat": {},
                       "receivable_msat": {},
                       "minimum_htlc_in_msat": {},
+                      "maximum_htlc_out_msat": {},
                       "spendable_msatoshi": {},
                       "receivable_msatoshi": {},
                       "their_to_self_delay": {},
@@ -1034,6 +1041,7 @@
                       "spendable_msat": {},
                       "receivable_msat": {},
                       "minimum_htlc_in_msat": {},
+                      "maximum_htlc_out_msat": {},
                       "spendable_msatoshi": {},
                       "receivable_msatoshi": {},
                       "their_to_self_delay": {},

lightningd/peer_control.c

@@ -861,6 +861,9 @@ static void json_add_channel(struct lightningd *ld,
 				    channel->our_config.htlc_minimum,
 				    "htlc_minimum_msat",
 				    "minimum_htlc_in_msat");
+	json_add_amount_msat_only(response,
+				  "maximum_htlc_out_msat",
+				  channel->htlc_maximum_msat);
 
 	/* The `to_self_delay` is imposed on the *other*
 	 * side, so our configuration `to_self_delay` is