lightningd: add option opening_anchor_channel to fundpsbt, utxopsbt.

This is needed when we know we're *opening* an anchor channel, to
override the "do we already have an anchor channel open?" logic.

Also, document the nonwrapped arg added in v23.02.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Added: JSON-RPC: `fundpsbt` and `utxopsbt` new parameter `opening_anchor_channel` so lightningd knowns it needs emergency reserve for anchors.

.msggen.json

@@ -664,6 +664,8 @@
             "FundPsbt.locktime": 6,
             "FundPsbt.min_witness_weight": 7,
             "FundPsbt.minconf": 4,
+            "FundPsbt.nonwrapped": 9,
+            "FundPsbt.opening_anchor_channel": 10,
             "FundPsbt.reserve": 5,
             "FundPsbt.satoshi": 1,
             "FundPsbt.startweight": 3
@@ -1468,6 +1470,7 @@
             "UtxoPsbt.feerate": 2,
             "UtxoPsbt.locktime": 6,
             "UtxoPsbt.min_witness_weight": 7,
+            "UtxoPsbt.opening_anchor_channel": 10,
             "UtxoPsbt.reserve": 5,
             "UtxoPsbt.reservedok": 8,
             "UtxoPsbt.satoshi": 1,
@@ -2780,6 +2783,14 @@
             "added": "pre-v0.10.1",
             "deprecated": false
         },
+        "FundPsbt.nonwrapped": {
+            "added": "v23.02",
+            "deprecated": false
+        },
+        "FundPsbt.opening_anchor_channel": {
+            "added": "v23.08",
+            "deprecated": false
+        },
         "FundPsbt.psbt": {
             "added": "pre-v0.10.1",
             "deprecated": false
@@ -5192,6 +5203,10 @@
             "added": "pre-v0.10.1",
             "deprecated": false
         },
+        "UtxoPsbt.opening_anchor_channel": {
+            "added": "v23.08",
+            "deprecated": false
+        },
         "UtxoPsbt.psbt": {
             "added": "pre-v0.10.1",
             "deprecated": false

cln-grpc/proto/node.proto

@@ -977,6 +977,8 @@ message FundpsbtRequest {
 	optional uint32 locktime = 6;
 	optional uint32 min_witness_weight = 7;
 	optional bool excess_as_change = 8;
+	optional bool nonwrapped = 9;
+	optional bool opening_anchor_channel = 10;
 }
 
 message FundpsbtResponse {
@@ -1025,6 +1027,7 @@ message UtxopsbtRequest {
 	optional uint32 locktime = 6;
 	optional uint32 min_witness_weight = 7;
 	optional bool excess_as_change = 9;
+	optional bool opening_anchor_channel = 10;
 }
 
 message UtxopsbtResponse {

cln-grpc/src/convert.rs

@@ -1987,6 +1987,8 @@ impl From<requests::FundpsbtRequest> for pb::FundpsbtRequest {
             locktime: c.locktime, // Rule #2 for type u32?
             min_witness_weight: c.min_witness_weight, // Rule #2 for type u32?
             excess_as_change: c.excess_as_change, // Rule #2 for type boolean?
+            nonwrapped: c.nonwrapped, // Rule #2 for type boolean?
+            opening_anchor_channel: c.opening_anchor_channel, // Rule #2 for type boolean?
         }
     }
 }
@@ -2026,6 +2028,7 @@ impl From<requests::UtxopsbtRequest> for pb::UtxopsbtRequest {
             locktime: c.locktime, // Rule #2 for type u32?
             min_witness_weight: c.min_witness_weight, // Rule #2 for type u32?
             excess_as_change: c.excess_as_change, // Rule #2 for type boolean?
+            opening_anchor_channel: c.opening_anchor_channel, // Rule #2 for type boolean?
         }
     }
 }
@@ -2656,6 +2659,8 @@ impl From<pb::FundpsbtRequest> for requests::FundpsbtRequest {
             locktime: c.locktime, // Rule #1 for type u32?
             min_witness_weight: c.min_witness_weight, // Rule #1 for type u32?
             excess_as_change: c.excess_as_change, // Rule #1 for type boolean?
+            nonwrapped: c.nonwrapped, // Rule #1 for type boolean?
+            opening_anchor_channel: c.opening_anchor_channel, // Rule #1 for type boolean?
         }
     }
 }
@@ -2693,6 +2698,7 @@ impl From<pb::UtxopsbtRequest> for requests::UtxopsbtRequest {
             locktime: c.locktime, // Rule #1 for type u32?
             min_witness_weight: c.min_witness_weight, // Rule #1 for type u32?
             excess_as_change: c.excess_as_change, // Rule #1 for type boolean?
+            opening_anchor_channel: c.opening_anchor_channel, // Rule #1 for type boolean?
         }
     }
 }

cln-rpc/src/model.rs

@@ -887,6 +887,10 @@ pub mod requests {
 	    pub min_witness_weight: Option<u32>,
 	    #[serde(skip_serializing_if = "Option::is_none")]
 	    pub excess_as_change: Option<bool>,
+	    #[serde(skip_serializing_if = "Option::is_none")]
+	    pub nonwrapped: Option<bool>,
+	    #[serde(skip_serializing_if = "Option::is_none")]
+	    pub opening_anchor_channel: Option<bool>,
 	}
 
 	impl From<FundpsbtRequest> for Request {
@@ -949,6 +953,8 @@ pub mod requests {
 	    pub min_witness_weight: Option<u32>,
 	    #[serde(skip_serializing_if = "Option::is_none")]
 	    pub excess_as_change: Option<bool>,
+	    #[serde(skip_serializing_if = "Option::is_none")]
+	    pub opening_anchor_channel: Option<bool>,
 	}
 
 	impl From<UtxopsbtRequest> for Request {

doc/schemas/fundpsbt.request.json

@@ -32,6 +32,14 @@
     },
     "excess_as_change": {
       "type": "boolean"
+    },
+    "nonwrapped": {
+      "added": "v23.02",
+      "type": "boolean"
+    },
+    "opening_anchor_channel": {
+      "added": "v23.08",
+      "type": "boolean"
     }
   }
 }

doc/schemas/utxopsbt.request.json

@@ -39,6 +39,10 @@
     },
     "excess_as_change": {
       "type": "boolean"
+    },
+    "opening_anchor_channel": {
+      "added": "v23.08",
+      "type": "boolean"
     }
   }
 }

wallet/reservation.c

@@ -492,7 +492,7 @@ static struct command_result *json_fundpsbt(struct command *cmd,
 	u32 *feerate_per_kw;
 	u32 *minconf, *weight, *min_witness_weight;
 	struct amount_sat *amount, input, diff, change;
-	bool all, *excess_as_change, *nonwrapped;
+	bool all, *excess_as_change, *nonwrapped, *keep_emergency_funds;
 	u32 *locktime, *reserve, maxheight;
 	u32 current_height;
 
@@ -510,9 +510,16 @@ static struct command_result *json_fundpsbt(struct command *cmd,
 			     &excess_as_change, false),
 		   p_opt_def("nonwrapped", param_bool,
 			     &nonwrapped, false),
+		   p_opt_def("opening_anchor_channel", param_bool,
+			     &keep_emergency_funds, false),
 		   NULL))
 		return command_param_failed();
 
+	/* If we have anchor channels, we definitely need to keep
+	 * emergency funds.  */
+	if (have_anchor_channel(cmd->ld))
+		*keep_emergency_funds = true;
+
 	all = amount_sat_eq(*amount, AMOUNT_SAT(-1ULL));
 	maxheight = minconf_to_maxheight(*minconf, cmd->ld);
 
@@ -608,7 +615,7 @@ static struct command_result *json_fundpsbt(struct command *cmd,
 
 	/* If needed, add change output for emergency_sat */
 	if (!change_for_emergency(cmd->ld,
-				  have_anchor_channel(cmd->ld),
+				  *keep_emergency_funds,
 				  utxos, *feerate_per_kw, *weight,
 				  &diff, &change)) {
 		return command_fail(cmd, FUND_CANNOT_AFFORD_WITH_EMERGENCY,
@@ -699,7 +706,7 @@ static struct command_result *json_utxopsbt(struct command *cmd,
 {
 	struct utxo **utxos;
 	u32 *feerate_per_kw, *weight, *min_witness_weight;
-	bool all, *reserved_ok, *excess_as_change;
+	bool all, *reserved_ok, *excess_as_change, *keep_emergency_funds;
 	struct amount_sat *amount, input, excess, change;
 	u32 current_height, *locktime, *reserve;
 
@@ -716,9 +723,16 @@ static struct command_result *json_utxopsbt(struct command *cmd,
 			     &min_witness_weight, 0),
 		   p_opt_def("excess_as_change", param_bool,
 			     &excess_as_change, false),
+		   p_opt_def("opening_anchor_channel", param_bool,
+			     &keep_emergency_funds, false),
 		   NULL))
 		return command_param_failed();
 
+	/* If we have anchor channels, we definitely need to keep
+	 * emergency funds.  */
+	if (have_anchor_channel(cmd->ld))
+		*keep_emergency_funds = true;
+
 	all = amount_sat_eq(*amount, AMOUNT_SAT(-1ULL));
 
 	input = AMOUNT_SAT(0);
@@ -787,7 +801,7 @@ static struct command_result *json_utxopsbt(struct command *cmd,
 
 	/* If needed, add change output for emergency_sat */
 	if (!change_for_emergency(cmd->ld,
-				  have_anchor_channel(cmd->ld),
+				  *keep_emergency_funds,
 				  utxos, *feerate_per_kw, *weight,
 				  &excess, &change)) {
 		return command_fail(cmd, FUND_CANNOT_AFFORD_WITH_EMERGENCY,