common: add tal_free_if_taken() helper for common case.

diff --git a/bitcoin/script.c b/bitcoin/script.c
index 30cc089..3b38eae 100644
--- a/bitcoin/script.c
+++ b/bitcoin/script.c
@@ -239,8 +239,7 @@ u8 *bitcoin_scriptsig_redeem(const tal_t *ctx,
 	script_push_bytes(&script, redeemscript,
 			  tal_count(redeemscript));
 
-	if (taken(redeemscript))
-		tal_free(redeemscript);
+	tal_free_if_taken(redeemscript);
 
 	return script;
 }
diff --git a/bitcoin/tx.c b/bitcoin/tx.c
index 0d5d6e5..fe25b10 100644
--- a/bitcoin/tx.c
+++ b/bitcoin/tx.c
@@ -359,8 +359,7 @@ void bitcoin_tx_input_set_witness(struct bitcoin_tx *tx, int innum,
 	wally_psbt_input_set_final_witness(&tx->psbt->inputs[innum], stack);
 	tal_wally_end(tx->psbt);
 
-	if (taken(witness))
-		tal_free(witness);
+	tal_free_if_taken(witness);
 }
 
 void bitcoin_tx_input_set_script(struct bitcoin_tx *tx, int innum, u8 *script)
diff --git a/common/cryptomsg.c b/common/cryptomsg.c
index 4225fef..8fb8d34 100644
--- a/common/cryptomsg.c
+++ b/common/cryptomsg.c
@@ -4,6 +4,7 @@
 #include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
 #include <ccan/mem/mem.h>
 #include <common/cryptomsg.h>
+#include <common/utils.h>
 #include <sodium/crypto_aead_chacha20poly1305.h>
 #include <wire/wire_io.h>
 
@@ -232,7 +233,6 @@ u8 *cryptomsg_encrypt_msg(const tal_t *ctx,
 
 	maybe_rotate_key(&cs->sn, &cs->sk, &cs->s_ck);
 
-	if (taken(msg))
-		tal_free(msg);
+	tal_free_if_taken(msg);
 	return out;
 }
diff --git a/common/features.c b/common/features.c
index 7573fea..94e0167 100644
--- a/common/features.c
+++ b/common/features.c
@@ -225,8 +225,7 @@ bool feature_set_or(struct feature_set *a,
 		for (size_t j = 0; j < tal_bytelen(b->bits[i])*8; j++) {
 			if (feature_is_set(b->bits[i], j)
 			    && feature_offered(a->bits[i], j)) {
-				if (taken(b))
-					tal_free(b);
+				tal_free_if_taken(b);
 				return false;
 			}
 		}
@@ -239,8 +238,7 @@ bool feature_set_or(struct feature_set *a,
 		}
 	}
 
-	if (taken(b))
-		tal_free(b);
+	tal_free_if_taken(b);
 	return true;
 }
 
@@ -252,8 +250,7 @@ bool feature_set_sub(struct feature_set *a,
 		for (size_t j = 0; j < tal_bytelen(b->bits[i])*8; j++) {
 			if (feature_is_set(b->bits[i], j)
 			    && !feature_offered(a->bits[i], j)) {
-				if (taken(b))
-					tal_free(b);
+				tal_free_if_taken(b);
 				return false;
 			}
 		}
@@ -268,8 +265,7 @@ bool feature_set_sub(struct feature_set *a,
 	}
 
 
-	if (taken(b))
-		tal_free(b);
+	tal_free_if_taken(b);
 	return true;
 }
 
@@ -534,8 +530,7 @@ u8 *featurebits_or(const tal_t *ctx, const u8 *f1 TAKES, const u8 *f2 TAKES)
 		result[l1 - l2 + i] |= f2[i];
 
 	/* Cleanup the featurebits if we were told to do so. */
-	if (taken(f2))
-		tal_free(f2);
+	tal_free_if_taken(f2);
 
 	return result;
 }
diff --git a/common/json_stream.c b/common/json_stream.c
index b272760..6a07460 100644
--- a/common/json_stream.c
+++ b/common/json_stream.c
@@ -190,8 +190,7 @@ void json_add_primitive(struct json_stream *js,
 			const char *val TAKES)
 {
 	json_add_primitive_fmt(js, fieldname, "%s", val);
-	if (taken(val))
-		tal_free(val);
+	tal_free_if_taken(val);
 }
 
 void json_add_string(struct json_stream *js,
@@ -200,8 +199,7 @@ void json_add_string(struct json_stream *js,
 {
 	if (json_filter_ok(js->filter, fieldname))
 		json_out_addstr(js->jout, fieldname, str);
-	if (taken(str))
-		tal_free(str);
+	tal_free_if_taken(str);
 }
 
 static char *json_member_direct(struct json_stream *js,
@@ -304,8 +302,7 @@ void json_add_stringn(struct json_stream *result, const char *fieldname,
 		      const char *value TAKES, size_t value_len)
 {
 	json_add_str_fmt(result, fieldname, "%.*s", (int)value_len, value);
-	if (taken(value))
-		tal_free(value);
+	tal_free_if_taken(value);
 }
 
 void json_add_bool(struct json_stream *result, const char *fieldname, bool value)
@@ -345,8 +342,7 @@ void json_add_escaped_string(struct json_stream *result, const char *fieldname,
 		memcpy(dest + 1, esc->s, strlen(esc->s));
 		dest[1+strlen(esc->s)] = '"';
 	}
-	if (taken(esc))
-		tal_free(esc);
+	tal_free_if_taken(esc);
 }
 
 void json_add_timeabs(struct json_stream *result, const char *fieldname,
@@ -607,8 +603,7 @@ void json_add_psbt(struct json_stream *stream,
 	const char *psbt_b64;
 	psbt_b64 = fmt_wally_psbt(NULL, psbt);
 	json_add_string(stream, fieldname, take(psbt_b64));
-	if (taken(psbt))
-		tal_free(psbt);
+	tal_free_if_taken(psbt);
 }
 
 void json_add_amount_msat(struct json_stream *result,
diff --git a/common/read_peer_msg.c b/common/read_peer_msg.c
index 292cc6e..c83d8f1 100644
--- a/common/read_peer_msg.c
+++ b/common/read_peer_msg.c
@@ -18,8 +18,7 @@ bool handle_peer_error_or_warning(struct per_peer_state *pps,
 	/* Simply log incoming warnings */
 	err = is_peer_warning(tmpctx, msg);
 	if (err) {
-		if (taken(msg))
-			tal_free(msg);
+		tal_free_if_taken(msg);
 		status_info("Received %s", err);
 		return true;
 	}
diff --git a/common/sphinx.c b/common/sphinx.c
index 5cecf68..6607429 100644
--- a/common/sphinx.c
+++ b/common/sphinx.c
@@ -165,8 +165,7 @@ void sphinx_add_hop(struct sphinx_path *path, const struct pubkey *pubkey,
 	size_t len = tal_bytelen(payload);
 	towire_bigsize(&with_len, len);
 	towire_u8_array(&with_len, payload, len);
-	if (taken(payload))
-		tal_free(payload);
+	tal_free_if_taken(payload);
 
 	if (!sphinx_add_hop_has_length(path, pubkey, take(with_len)))
 		abort();
diff --git a/common/utils.c b/common/utils.c
index 83c8b59..102eed7 100644
--- a/common/utils.c
+++ b/common/utils.c
@@ -171,8 +171,7 @@ char *utf8_str(const tal_t *ctx, const u8 *buf TAKES, size_t buflen)
 	char *ret;
 
 	if (!utf8_check(buf, buflen)) {
-		if (taken(buf))
-			tal_free(buf);
+		tal_free_if_taken(buf);
 		return NULL;
 	}
 
diff --git a/common/utils.h b/common/utils.h
index a95da84..cc378e6 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -97,6 +97,13 @@ void tal_arr_remove_(void *p, size_t elemsize, size_t n);
 		(*(p))[n] = (v);					\
 	} while(0)
 
+/* Helper to free an ptr if it's taken() */
+static inline void tal_free_if_taken(const tal_t *p)
+{
+	if (taken(p))
+		tal_free(p);
+}
+
 /* Check for valid UTF-8 */
 bool utf8_check(const void *buf, size_t buflen);
 
diff --git a/connectd/multiplex.c b/connectd/multiplex.c
index 0c5b0e4..b81c367 100644
--- a/connectd/multiplex.c
+++ b/connectd/multiplex.c
@@ -428,8 +428,7 @@ static u8 *process_batch_elements(const tal_t *ctx, struct peer *peer, const u8
 
 	} while(plen);
 
-	if (taken(msg))
-		tal_free(msg);
+	tal_free_if_taken(msg);
 
 	return ret;
 }
diff --git a/db/utils.c b/db/utils.c
index 2091111..ebe7c35 100644
--- a/db/utils.c
+++ b/db/utils.c
@@ -200,8 +200,7 @@ void db_exec_prepared_v2(struct db_stmt *stmt TAKES)
 		db_fatal(stmt->db, "Error executing statement: %s", stmt->error);
 	}
 
-	if (taken(stmt))
-	    tal_free(stmt);
+	tal_free_if_taken(stmt);
 }
 
 size_t db_count_changes(struct db_stmt *stmt)
@@ -221,8 +220,7 @@ u64 db_last_insert_id_v2(struct db_stmt *stmt TAKES)
 	assert(stmt->executed);
 	id = stmt->db->config->last_insert_id_fn(stmt);
 
-	if (taken(stmt))
-		tal_free(stmt);
+	tal_free_if_taken(stmt);
 
 	return id;
 }
diff --git a/devtools/gossmap-compress.c b/devtools/gossmap-compress.c
index 5c0be91..662b441 100644
--- a/devtools/gossmap-compress.c
+++ b/devtools/gossmap-compress.c
@@ -304,8 +304,7 @@ static void write_msg_to_gstore(int outfd, const u8 *msg TAKES)
 	    || !write_all(outfd, msg, tal_bytelen(msg))) {
 		err(1, "Writing gossip_store");
 	}
-	if (taken(msg))
-		tal_free(msg);
+	tal_free_if_taken(msg);
 }
 
 /* BOLT #7:
diff --git a/gossipd/gossipd.c b/gossipd/gossipd.c
index 6c0d073..a2c6fdf 100644
--- a/gossipd/gossipd.c
+++ b/gossipd/gossipd.c
@@ -103,8 +103,7 @@ void queue_peer_msg(struct daemon *daemon,
 	u8 *outermsg = towire_gossipd_send_gossip(NULL, peer, msg);
 	daemon_conn_send(daemon->connectd, take(outermsg));
 
-	if (taken(msg))
-		tal_free(msg);
+	tal_free_if_taken(msg);
 }
 
 /*~Routines to handle gossip messages from peer, forwarded by connectd.
diff --git a/lightningd/channel.c b/lightningd/channel.c
index b15fdb2..6ca82cb 100644
--- a/lightningd/channel.c
+++ b/lightningd/channel.c
@@ -1249,8 +1249,7 @@ void channel_set_billboard(struct channel *channel, bool perm, const char *str)
 
 	if (str) {
 		*p = tal_fmt(channel, "%s:%s", channel_state_name(channel), str);
-		if (taken(str))
-			tal_free(str);
+		tal_free_if_taken(str);
 	}
 }
 
diff --git a/lightningd/channel_gossip.c b/lightningd/channel_gossip.c
index cb5a42d..5daa79b 100644
--- a/lightningd/channel_gossip.c
+++ b/lightningd/channel_gossip.c
@@ -378,8 +378,7 @@ static void msg_to_peer(const struct peer *peer, const u8 *msg TAKES)
 								 msg)));
 	}
 
-	if (taken(msg))
-		tal_free(msg);
+	tal_free_if_taken(msg);
 }
 
 static void addgossip_reply(struct subd *gossipd,
@@ -1110,8 +1109,7 @@ void channel_gossip_update_from_gossipd(struct channel *channel,
 	 * when we restarted; ignore, as it will catch up soon. */
 	case CGOSSIP_CHANNEL_ANNOUNCED_DEAD:
 	case CGOSSIP_CHANNEL_ANNOUNCED_DYING:
-		if (taken(channel_update))
-			tal_free(channel_update);
+		tal_free_if_taken(channel_update);
 		return;
 
 	/* This happens: we step back a block when restarting. */
diff --git a/lightningd/jsonrpc.c b/lightningd/jsonrpc.c
index cb73246..6d9e83a 100644
--- a/lightningd/jsonrpc.c
+++ b/lightningd/jsonrpc.c
@@ -1571,8 +1571,7 @@ struct jsonrpc_request *jsonrpc_request_start_(
 	} else {
 		r->id = tal_fmt(r, "\"cln:%s#%"PRIu64"\"", method, next_request_id);
 	}
-	if (taken(id_prefix))
-		tal_free(id_prefix);
+	tal_free_if_taken(id_prefix);
 	next_request_id++;
 	r->notify_cb = notify_cb;
 	r->response_cb = response_cb;
diff --git a/lightningd/peer_htlcs.c b/lightningd/peer_htlcs.c
index b643375..5058039 100644
--- a/lightningd/peer_htlcs.c
+++ b/lightningd/peer_htlcs.c
@@ -277,8 +277,7 @@ void local_fail_in_htlc(struct htlc_in *hin, const u8 *failmsg TAKES)
 							 hin->shared_secret,
 							 failmsg);
 
-	if (taken(failmsg))
-		tal_free(failmsg);
+	tal_free_if_taken(failmsg);
 
 	fail_in_htlc(hin, take(failonion));
 }
@@ -994,8 +993,7 @@ static u8 *prepend_length(const tal_t *ctx, const u8 *payload TAKES)
 	ret = tal_arr(ctx, u8, len + tal_bytelen(payload));
 	memcpy(ret, buf, len);
 	memcpy(ret + len, payload, tal_bytelen(payload));
-	if (taken(payload))
-		tal_free(payload);
+	tal_free_if_taken(payload);
 	return ret;
 }
 
diff --git a/lightningd/plugin.c b/lightningd/plugin.c
index 447eb59..a9098ad 100644
--- a/lightningd/plugin.c
+++ b/lightningd/plugin.c
@@ -357,8 +357,7 @@ struct plugin *plugin_register(struct plugins *plugins, const char* path TAKES,
 					    "Plugin changed, needs restart.");
 				break;
 			}
-			if (taken(path))
-				tal_free(path);
+			tal_free_if_taken(path);
 			return NULL;
 		}
 	}
@@ -2454,8 +2453,7 @@ bool plugin_single_notify(struct plugin *p,
 	} else
 		interested = false;
 
-	if (taken(n))
-		tal_free(n);
+	tal_free_if_taken(n);
 
 	return interested;
 }
diff --git a/lightningd/watch.c b/lightningd/watch.c
index fdc57f0..e18ea8d 100644
--- a/lightningd/watch.c
+++ b/lightningd/watch.c
@@ -315,8 +315,7 @@ void txwatch_inform(const struct chain_topology *topo,
 	}
 
 	/* If we don't clone above, handle take() now */
-	if (taken(tx))
-		tal_free(tx);
+	tal_free_if_taken(tx);
 }
 
 struct scriptpubkeywatch {
diff --git a/onchaind/onchaind.c b/onchaind/onchaind.c
index 5f2ad78..9b9beb2 100644
--- a/onchaind/onchaind.c
+++ b/onchaind/onchaind.c
@@ -215,8 +215,7 @@ static void send_coin_mvt(struct chain_coin_mvt *mvt TAKES)
 	wire_sync_write(REQ_FD,
 			take(towire_onchaind_notify_coin_mvt(NULL, mvt)));
 
-	if (taken(mvt))
-		tal_free(mvt);
+	tal_free_if_taken(mvt);
 }
 
 static void record_channel_withdrawal(const struct bitcoin_txid *tx_txid,
diff --git a/onchaind/test/run-grind_feerate-bug.c b/onchaind/test/run-grind_feerate-bug.c
index a77627b..4854902 100644
--- a/onchaind/test/run-grind_feerate-bug.c
+++ b/onchaind/test/run-grind_feerate-bug.c
@@ -229,8 +229,7 @@ u8 *wire_sync_read(const tal_t *ctx, int fd UNNEEDED)
 
 bool wire_sync_write(int fd UNNEEDED, const void *msg TAKES)
 {
-	if (taken(msg))
-		tal_free(msg);
+	tal_free_if_taken(msg);
 	return true;
 }
 
diff --git a/plugins/bkpr/test/run-recorder.c b/plugins/bkpr/test/run-recorder.c
index db05aae..0f3f6d0 100644
--- a/plugins/bkpr/test/run-recorder.c
+++ b/plugins/bkpr/test/run-recorder.c
@@ -118,8 +118,7 @@ struct json_out *json_out_obj(const tal_t *ctx,
 	json_out_start(jout, NULL, '{');
 	if (str)
 		json_out_addstr(jout, fieldname, str);
-	if (taken(str))
-		tal_free(str);
+	tal_free_if_taken(str);
 	json_out_end(jout, '}');
 	json_out_finished(jout);
 
@@ -540,8 +539,7 @@ done:
 	assert(json_parse_input(&parser, &toks, buf, strlen(buf), &complete));
 	assert(complete);
 
-	if (taken(params))
-		tal_free(params);
+	tal_free_if_taken(params);
 	*resp = buf;
 	return toks;
 }
diff --git a/plugins/libplugin-pay.c b/plugins/libplugin-pay.c
index a189560..9504950 100644
--- a/plugins/libplugin-pay.c
+++ b/plugins/libplugin-pay.c
@@ -1547,8 +1547,7 @@ static u8 *patch_channel_update(const tal_t *ctx, u8 *channel_update TAKES)
 		fixed = tal_arr(ctx, u8, 0);
 		towire_u16(&fixed, WIRE_CHANNEL_UPDATE);
 		towire(&fixed, channel_update, tal_bytelen(channel_update));
-		if (taken(channel_update))
-			tal_free(channel_update);
+		tal_free_if_taken(channel_update);
 		return fixed;
 	} else {
 		return tal_dup_talarr(ctx, u8, channel_update);
diff --git a/plugins/libplugin.c b/plugins/libplugin.c
index 8630593..b39058d 100644
--- a/plugins/libplugin.c
+++ b/plugins/libplugin.c
@@ -543,8 +543,7 @@ struct json_out *json_out_obj(const tal_t *ctx,
 	json_out_start(jout, NULL, '{');
 	if (str)
 		json_out_addstr(jout, fieldname, str);
-	if (taken(str))
-		tal_free(str);
+	tal_free_if_taken(str);
 	json_out_end(jout, '}');
 	json_out_finished(jout);
 
@@ -791,8 +790,7 @@ static const jsmntok_t *sync_req(const tal_t *ctx,
 		json_out_start(jout, "params", '{');
 		json_out_end(jout, '}');
 	}
-	if (taken(params))
-		tal_free(params);
+	tal_free_if_taken(params);
 
 	/* If we're past init, we may need a new fd (the old one
 	 * is being used for async comms). */
diff --git a/plugins/renepay/routefail.c b/plugins/renepay/routefail.c
index 4f450c6..a6df2c2 100644
--- a/plugins/renepay/routefail.c
+++ b/plugins/renepay/routefail.c
@@ -73,8 +73,7 @@ static u8 *patch_channel_update(const tal_t *ctx, u8 *channel_update TAKES)
 		fixed = tal_arr(ctx, u8, 0);
 		towire_u16(&fixed, WIRE_CHANNEL_UPDATE);
 		towire(&fixed, channel_update, tal_bytelen(channel_update));
-		if (taken(channel_update))
-			tal_free(channel_update);
+		tal_free_if_taken(channel_update);
 		return fixed;
 	} else {
 		return tal_dup_talarr(ctx, u8, channel_update);
diff --git a/wallet/account_migration.c b/wallet/account_migration.c
index 812b4d6..f913c14 100644
--- a/wallet/account_migration.c
+++ b/wallet/account_migration.c
@@ -184,8 +184,7 @@ static struct chain_event **find_chain_events(const tal_t *ctx,
 		tal_arr_expand(&results, e);
 	}
 
-	if (taken(stmt))
-		tal_free(stmt);
+	tal_free_if_taken(stmt);
 
 	return results;
 }
diff --git a/wallet/invoices.c b/wallet/invoices.c
index 085618c..3da3904 100644
--- a/wallet/invoices.c
+++ b/wallet/invoices.c
@@ -278,10 +278,8 @@ bool invoices_create(struct invoices *invoices,
 	u64 now = clock_time().ts.tv_sec;
 
 	if (invoices_find_by_label(invoices, inv_dbid, label)) {
-		if (taken(msat))
-			tal_free(msat);
-		if (taken(label))
-			tal_free(label);
+		tal_free_if_taken(msat);
+		tal_free_if_taken(label);
 		return false;
 	}
 
@@ -335,10 +333,8 @@ bool invoices_create(struct invoices *invoices,
 		install_expiration_timer(invoices);
 	}
 
-	if (taken(msat))
-		tal_free(msat);
-	if (taken(label))
-		tal_free(label);
+	tal_free_if_taken(msat);
+	tal_free_if_taken(label);
 	return true;
 }
 
diff --git a/wallet/wallet.c b/wallet/wallet.c
index d2a3e21..bfdf31e 100644
--- a/wallet/wallet.c
+++ b/wallet/wallet.c
@@ -6922,8 +6922,7 @@ static u64 insert_channel_mvt(struct lightningd *ld,
 	db_exec_prepared_v2(take(stmt));
 
 	notify_channel_mvt(ld, chan_mvt, id);
-	if (taken(chan_mvt))
-		tal_free(chan_mvt);
+	tal_free_if_taken(chan_mvt);
 
 	return id;
 }
@@ -7115,8 +7114,7 @@ void wallet_save_chain_mvt(struct lightningd *ld,
 	id = insert_chain_mvt(ld, ld->wallet->db, chain_mvt);
 	notify_chain_mvt(ld, chain_mvt, id);
 out:
-	if (taken(chain_mvt))
-		tal_free(chain_mvt);
+	tal_free_if_taken(chain_mvt);
 }
 
 static void db_cols_account(struct db_stmt *stmt,
diff --git a/wire/wire_sync.c b/wire/wire_sync.c
index ce2107b..9545151 100644
--- a/wire/wire_sync.c
+++ b/wire/wire_sync.c
@@ -1,6 +1,7 @@
 #include "config.h"
 #include <assert.h>
 #include <ccan/read_write_all/read_write_all.h>
+#include <common/utils.h>
 #include <errno.h>
 #include <wire/wire_io.h>
 #include <wire/wire_sync.h>
@@ -14,8 +15,7 @@ bool wire_sync_write(int fd, const void *msg TAKES)
 	ret = write_all(fd, &hdr, sizeof(hdr))
 		&& write_all(fd, msg, tal_count(msg));
 
-	if (taken(msg))
-		tal_free(msg);
+	tal_free_if_taken(msg);
 	return ret;
 }