common/json_stream.c: Implement a `json_add_jsonstr` to add already-JSON strings to `json_stream` objects.

Also incidentally fixes #3613

ChangeLog-none

common/json_stream.c

@@ -162,6 +162,18 @@ void json_add_member(struct json_stream *js,
 	va_end(ap);
 }
 
+void json_add_jsonstr(struct json_stream *js,
+		      const char *fieldname,
+		      const char *jsonstr)
+{
+	char *p;
+	size_t len = strlen(jsonstr);
+
+	p = json_member_direct(js, fieldname, len);
+
+	memcpy(p, jsonstr, len);
+}
+
 /* This is where we read the json_stream and write it to conn */
 static struct io_plan *json_stream_output_write(struct io_conn *conn,
 						struct json_stream *js)

common/json_stream.h

@@ -114,6 +114,18 @@ void json_add_member(struct json_stream *js,
 		     bool quote,
 		     const char *fmt, ...) PRINTF_FMT(4,5);
 
+/**
+ * json_add_jsonstr - add a JSON entity in a string that is already
+ * JSON-formatted.
+ * @js: the json_stream.
+ * @fieldname: fieldname (if in object), otherwise must be NULL.
+ * @jsonstr: the JSON entity, must be non-NULL, a null-terminated
+ * string that is already formatted in JSON.
+ */
+void json_add_jsonstr(struct json_stream *js,
+		      const char *fieldname,
+		      const char *jsonstr);
+
 /**
  * json_member_direct - start a generic member.
  * @js: the json_stream.

plugins/fundchannel.c

@@ -44,17 +44,6 @@ struct funding_req {
 	const char *error;
 };
 
-/* Helper to copy JSON object directly into a json_out */
-static void json_out_add_raw_len(struct json_out *jout,
-				 const char *fieldname,
-				 const char *jsonstr, size_t len)
-{
-	char *p;
-
-	p = json_out_member_direct(jout, fieldname, len);
-	memcpy(p, jsonstr, len);
-}
-
 static struct command_result *send_prior(struct command *cmd,
 					 const char *buf,
 					 const jsmntok_t *error,
@@ -220,8 +209,7 @@ static void txprepare(struct json_stream *js,
 	if (fr->minconf)
 		json_add_u32(js, "minconf", *fr->minconf);
 	if (fr->utxo_str)
-		json_out_add_raw_len(js->jout, "utxos", fr->utxo_str,
-				     strlen(fr->utxo_str));
+		json_add_jsonstr(js, "utxos", fr->utxo_str);
 }
 
 static struct command_result *prepare_actual(struct command *cmd,

plugins/pay.c

@@ -147,13 +147,6 @@ static void json_out_add_raw_len(struct json_out *jout,
 	memcpy(p, jsonstr, len);
 }
 
-static void json_out_add_raw(struct json_out *jout,
-			     const char *fieldname,
-			     const char *jsonstr)
-{
-	json_out_add_raw_len(jout, fieldname, jsonstr, strlen(jsonstr));
-}
-
 static struct json_out *failed_start(struct pay_command *pc)
 {
 	struct pay_attempt *attempt = current_attempt(pc);
@@ -179,6 +172,15 @@ static const jsmntok_t *copy_member(struct json_out *ret,
 	if (!m)
 		return NULL;
 
+	/* FIXME: The fact it is a string is probably the wrong thing
+	 * to handle: if it *is* a string we should probably copy
+	 * the quote marks, but json_tok_full/json_tok_full_len
+	 * specifically remove those.
+	 * It works *now* because it is only used in "code" and
+	 * "data": "code" is always numeric, and "data" is usually
+	 * a JSON object/key-value table, but pure stromgs will
+	 * probably result in invalid JSON.
+	 */
 	/* Literal copy: it's already JSON escaped, and may be a string. */
 	json_out_add_raw_len(ret, membername,
 			     json_tok_full(buf, m), json_tok_full_len(m));
@@ -262,7 +264,7 @@ static struct command_result *waitsendpay_expired(struct command *cmd,
 	for (size_t i = 0; i < tal_count(pc->ps->attempts); i++) {
 		json_object_start(data, NULL);
 		if (pc->ps->attempts[i].route)
-			json_add_member(data, "route", true, "%s",
+			json_add_jsonstr(data, "route",
 					 pc->ps->attempts[i].route);
 		json_out_add_splice(data->jout, "failure",
 				    pc->ps->attempts[i].failure);
@@ -835,7 +837,7 @@ static struct command_result *getroute_done(struct command *cmd,
 	attempt->sendpay = true;
 	req = jsonrpc_request_start(cmd->plugin, cmd, "sendpay",
 				    sendpay_done, sendpay_error, pc);
-	json_out_add_raw(req->js->jout, "route", attempt->route);
+	json_add_jsonstr(req->js, "route", attempt->route);
 	json_add_string(req->js, "payment_hash", pc->payment_hash);
 	json_add_string(req->js, "bolt11", pc->ps->bolt11);
 	if (pc->label)
@@ -1420,7 +1422,7 @@ static void add_attempt(struct json_stream *ret,
 	}
 
 	if (attempt->route)
-		json_add_member(ret, "route", true, "%s", attempt->route);
+		json_add_jsonstr(ret, "route", attempt->route);
 
 	if (attempt->failure)
 		json_out_add_splice(ret->jout, "failure", attempt->failure);