ElementsProject · rustyrussell · Jul 15, 2020 · Jul 14, 2020 · Jul 14, 2020 · Jul 15, 2020
diff --git a/bitcoin/tx.h b/bitcoin/tx.h
@@ -12,6 +12,10 @@
 #include <wally_transaction.h>
 
 #define BITCOIN_TX_DEFAULT_SEQUENCE 0xFFFFFFFF
+
+/* BIP 125: Any nsequence < 0xFFFFFFFE is replacable.
+ * And bitcoind uses this value. */
+#define BITCOIN_TX_RBF_SEQUENCE 0xFFFFFFFD
 struct wally_psbt;
 
 struct bitcoin_txid {

diff --git a/common/utxo.c b/common/utxo.c
@@ -76,7 +76,6 @@ struct bitcoin_tx *tx_spending_utxos(const tal_t *ctx,
 	struct pubkey key;
 	u8 *scriptSig, *scriptPubkey, *redeemscript;
 
-	assert(num_output);
 	size_t outcount = add_change_output ? 1 + num_output : num_output;
 	struct bitcoin_tx *tx = bitcoin_tx(ctx, chainparams, tal_count(utxos),
 					   outcount, nlocktime);

diff --git a/common/utxo.h b/common/utxo.h
@@ -39,6 +39,9 @@ struct utxo {
 	/* NULL if not spent yet, otherwise, the block the spending transaction is in */
 	const u32 *spendheight;
 
+	/* Block this utxo becomes unreserved, if applicable */
+	u32 *reserved_til;
+
 	/* The scriptPubkey if it is known */
 	u8 *scriptPubkey;
 

@@ -1107,28 +1107,37 @@ def txsend(self, txid):
         }
         return self.call("txsend", payload)
 
-    def reserveinputs(self, outputs, feerate=None, minconf=None, utxos=None):
+    def reserveinputs(self, psbt, exclusive=True):
         """
-        Reserve UTXOs and return a psbt for a 'stub' transaction that
-        spends the reserved UTXOs.
+        Reserve any inputs in this psbt.
         """
         payload = {
-            "outputs": outputs,
-            "feerate": feerate,
-            "minconf": minconf,
-            "utxos": utxos,
+            "psbt": psbt,
+            "exclusive": exclusive,
         }
         return self.call("reserveinputs", payload)
 
     def unreserveinputs(self, psbt):
         """
-        Unreserve UTXOs that were previously reserved.
+        Unreserve (or reduce reservation) on any UTXOs in this psbt were previously reserved.
         """
         payload = {
             "psbt": psbt,
         }
         return self.call("unreserveinputs", payload)
 
+    def fundpsbt(self, satoshi, feerate, minconf=None, reserve=True):
+        """
+        Create a PSBT with inputs sufficient to give an output of satoshi.
+        """
+        payload = {
+            "satoshi": satoshi,
+            "feerate": feerate,
+            "minconf": minconf,
+            "reserve": reserve,
+        }
+        return self.call("fundpsbt", payload)
+
     def signpsbt(self, psbt):
         """
         Add internal wallet's signatures to PSBT

diff --git a/doc/Makefile b/doc/Makefile
@@ -23,6 +23,7 @@ MANPAGES := doc/lightning-cli.1 \
 	doc/lightning-fundchannel_start.7 \
 	doc/lightning-fundchannel_complete.7 \
 	doc/lightning-fundchannel_cancel.7 \
+	doc/lightning-fundpsbt.7 \
 	doc/lightning-getroute.7 \
 	doc/lightning-getsharedsecret.7 \
 	doc/lightning-hsmtool.8 \

diff --git a/doc/index.rst b/doc/index.rst
@@ -45,6 +45,7 @@ c-lightning Documentation
    lightning-fundchannel_cancel <lightning-fundchannel_cancel.7.md>
    lightning-fundchannel_complete <lightning-fundchannel_complete.7.md>
    lightning-fundchannel_start <lightning-fundchannel_start.7.md>
+   lightning-fundpsbt <lightning-fundpsbt.7.md>
    lightning-getroute <lightning-getroute.7.md>
    lightning-getsharedsecret <lightning-getsharedsecret.7.md>
    lightning-hsmtool <lightning-hsmtool.8.md>

diff --git a/doc/lightning-fundpsbt.7 b/doc/lightning-fundpsbt.7
diff --git a/doc/lightning-fundpsbt.7.md b/doc/lightning-fundpsbt.7.md
@@ -0,0 +1,69 @@
+lightning-fundpsbt -- Command to populate PSBT inputs from the wallet
+================================================================
+
+SYNOPSIS
+--------
+
+**fundpsbt** *satoshi* *feerate* \[*minconf*\] \[*reserve*\]
+
+DESCRIPTION
+-----------
+
+`fundpsbt` is a low-level RPC command which creates a PSBT using unreserved
+inputs in the wallet, optionally reserving them as well.
+
+*satoshi* is the minimum satoshi value of the output(s) needed (or the
+string "all" meaning use all unreserved inputs).  If a value, it can
+be a whole number, a whole number ending in *sat*, a whole number
+ending in *000msat*, or a number with 1 to 8 decimal places ending in
+*btc*.
+
+You calculate the value by starting with the amount you want to pay
+and adding the fee which will be needed to pay for the base of the
+transaction plus that output, and any other outputs and inputs you
+will add to the final transaction.
+
+*feerate* is a number, with an optional suffix: *perkw* means the
+number is interpreted as satoshi-per-kilosipa (weight), and *perkb*
+means it is interpreted bitcoind-style as
+satoshi-per-kilobyte. Omitting the suffix is equivalent to *perkb*.
+
+*minconf* specifies the minimum number of confirmations that used
+outputs should have. Default is 1.
+
+*reserve* is a boolean: if true (the default), then *reserveinputs* is
+called (successfully, with *exclusive* true) on the returned PSBT.
+
+RETURN VALUE
+------------
+
+On success, returns the *psbt* containing the inputs, and
+*excess_msat* containing the amount above *satoshi* which is
+available.  This could be zero, or dust.  If *satoshi* was "all",
+then *excess_msat* is the entire amount once fees are subtracted
+for the weights of the inputs.
+
+If *reserve* was true, then a *reservations* array is returned,
+exactly like *reserveinputs*.
+
+On error the returned object will contain `code` and `message` properties,
+with `code` being one of the following:
+
+- -32602: If the given parameters are wrong.
+- -1: Catchall nonspecific error.
+- 301: Insufficient UTXOs to meet *satoshi* value.
+
+AUTHOR
+------
+
+Rusty Russell <<rusty@rustcorp.com.au>> is mainly responsible.
+
+SEE ALSO
+--------
+
+lightning-reserveinputs(7), lightning-unreserveinputs(7).
+
+RESOURCES
+---------
+
+Main web site: <https://github.com/ElementsProject/lightning>
diff --git a/doc/lightning-reserveinputs.7 b/doc/lightning-reserveinputs.7