json_to_psbt: fix API to match other allocating json_to functions.

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

common/json_helpers.c

@@ -140,11 +140,10 @@ bool json_to_preimage(const char *buffer, const jsmntok_t *tok, struct preimage
 	return hex_decode(buffer + tok->start, hexlen, preimage->r, sizeof(preimage->r));
 }
 
-bool json_to_psbt(const tal_t *ctx, const char *buffer,
-		  const jsmntok_t *tok, struct wally_psbt **dest)
+struct wally_psbt *json_to_psbt(const tal_t *ctx, const char *buffer,
+				const jsmntok_t *tok)
 {
-	*dest = psbt_from_b64(ctx, buffer + tok->start, tok->end - tok->start);
-	return dest != NULL;
+	return psbt_from_b64(ctx, buffer + tok->start, tok->end - tok->start);
 }
 
 void json_add_node_id(struct json_stream *response,

common/json_helpers.h

@@ -26,8 +26,8 @@ bool json_to_preimage(const char *buffer, const jsmntok_t *tok, struct preimage
 bool json_to_secret(const char *buffer, const jsmntok_t *tok, struct secret *dest);
 
 /* Extract a psbt from this. */
-bool json_to_psbt(const tal_t *ctx, const char *buffer,
-		  const jsmntok_t *tok, struct wally_psbt **dest);
+struct wally_psbt *json_to_psbt(const tal_t *ctx, const char *buffer,
+				const jsmntok_t *tok);
 
 /* Extract a pubkey from this */
 bool json_to_pubkey(const char *buffer, const jsmntok_t *tok,

lightningd/dual_open_control.c

@@ -218,8 +218,6 @@ hook_extract_psbt(const tal_t *ctx, struct subd *dualopend, const char *buffer,
 		  bool allow_empty,
 		  struct wally_psbt **out)
 {
-	struct wally_psbt *returned_psbt;
-
 	if (!buffer)
 		fatal("Plugin must return a valid response to %s", hook_name);
 
@@ -250,13 +248,13 @@ hook_extract_psbt(const tal_t *ctx, struct subd *dualopend, const char *buffer,
 		return true;
 	}
 
-	if (!json_to_psbt(ctx, buffer, psbt_tok, &returned_psbt))
+	*out = json_to_psbt(ctx, buffer, psbt_tok);
+	if (!*out)
 		fatal("Plugin must return a valid 'psbt' to a 'continue'd"
 		      "%s %.*s", hook_name,
 		      toks[0].end - toks[0].start,
 		      buffer + toks[0].start);
 
-	*out = returned_psbt;
 	return true;
 }
 

plugins/spender/openchannel.c

@@ -571,8 +571,8 @@ static void json_peer_sigs(struct command *cmd,
 			   json_tok_full_len(params),
 			   json_tok_full(buf, params));
 
-	if (!json_to_psbt(cmd, buf, psbt_tok,
-			  cast_const2(struct wally_psbt **, &psbt)))
+	psbt = json_to_psbt(cmd, buf, psbt_tok);
+	if (!psbt)
 		plugin_err(cmd->plugin,
 			   "Unable to parse openchannel_peer_sigs.signed_psbt "
 			   "%.*s",
@@ -705,7 +705,8 @@ openchannel_update_ok(struct command *cmd,
 			   json_tok_full_len(result),
 			   json_tok_full(buf, result));
 
-	if (!json_to_psbt(dest->mfc, buf, psbt_tok, &dest->updated_psbt))
+	dest->updated_psbt = json_to_psbt(dest->mfc, buf, psbt_tok);
+	if (!dest->updated_psbt)
 		plugin_err(cmd->plugin,
 			   "`openchannel_update` returned invalid "
 			   "'psbt': %.*s",
@@ -939,7 +940,8 @@ openchannel_init_ok(struct command *cmd,
 			   "'psbt': %.*s",
 			   json_tok_full_len(result),
 			   json_tok_full(buf, result));
-	if (!json_to_psbt(dest->mfc, buf, psbt_tok, &dest->updated_psbt))
+	dest->updated_psbt = json_to_psbt(dest->mfc, buf, psbt_tok);
+	if (!dest->updated_psbt)
 		plugin_err(cmd->plugin,
 			   "openchannel_init returned invalid "
 			   "'psbt': %.*s",