lightningd: explicitly remember if JSON id was a string.

This lets us use 'cmd->id' as an unquoted string (for building
new ids!).

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

lightningd/jsonrpc.c

@@ -192,9 +192,7 @@ static struct command_result *json_stop(struct command *cmd,
 	jout = json_out_new(tmpctx);
 	json_out_start(jout, NULL, '{');
 	json_out_addstr(jout, "jsonrpc", "2.0");
-	/* id may be a string or number, so copy direct. */
-	memcpy(json_out_member_direct(jout, "id", strlen(cmd->id)),
-	       cmd->id, strlen(cmd->id));
+	json_out_add(jout, "id", cmd->id_is_string, "%s", cmd->id);
 	json_out_addstr(jout, "result", "Shutdown complete");
 	json_out_end(jout, '}');
 	json_out_finished(jout);
@@ -533,7 +531,10 @@ void json_notify_fmt(struct command *cmd,
 	json_add_string(js, "jsonrpc", "2.0");
 	json_add_string(js, "method", "message");
 	json_object_start(js, "params");
-	json_add_string(js, "id", cmd->id);
+	if (cmd->id_is_string)
+		json_add_string(js, "id", cmd->id);
+	else
+		json_add_jsonstr(js, "id", cmd->id, strlen(cmd->id));
 	json_add_string(js, "level", log_level_name(level));
 	json_add_string(js, "message", tal_vfmt(tmpctx, fmt, ap));
 	json_object_end(js);
@@ -578,7 +579,10 @@ static struct json_stream *json_start(struct command *cmd)
 
 	json_object_start(js, NULL);
 	json_add_string(js, "jsonrpc", "2.0");
-	json_add_jsonstr(js, "id", cmd->id, strlen(cmd->id));
+	if (cmd->id_is_string)
+		json_add_string(js, "id", cmd->id);
+	else
+		json_add_jsonstr(js, "id", cmd->id, strlen(cmd->id));
 	return js;
 }
 
@@ -892,9 +896,8 @@ parse_request(struct json_connection *jcon, const jsmntok_t tok[])
 	c->ld = jcon->ld;
 	c->pending = false;
 	c->json_stream = NULL;
-	c->id = tal_strndup(c,
-			    json_tok_full(jcon->buffer, id),
-			    json_tok_full_len(id));
+	c->id_is_string = (id->type == JSMN_STRING);
+	c->id = json_strdup(c, jcon->buffer, id);
 	c->mode = CMD_NORMAL;
 	list_add_tail(&jcon->commands, &c->list);
 	tal_add_destructor(c, destroy_command);

lightningd/jsonrpc.h

@@ -27,6 +27,8 @@ struct command {
 	struct lightningd *ld;
 	/* The 'id' which we need to include in the response. */
 	const char *id;
+	/* If 'id' needs to be quoted (i.e. it's a string) */
+	bool id_is_string;
 	/* What command we're running (for logging) */
 	const struct json_command *json_cmd;
 	/* The connection, or NULL if it closed. */

lightningd/plugin.c

@@ -1025,7 +1025,7 @@ static void json_stream_forward_change_id(struct json_stream *stream,
 					  const jsmntok_t *toks,
 					  const jsmntok_t *idtok,
 					  const char *new_id,
-					  bool add_quotes)
+					  bool new_id_is_str)
 {
 	/* We copy everything, but replace the id. Special care has to
 	 * be taken when the id that is being replaced is a string. If
@@ -1033,12 +1033,16 @@ static void json_stream_forward_change_id(struct json_stream *stream,
 	 * new_id into a string, or even worse, quote a string id
 	 * twice. */
 	size_t offset = 0;
+	bool add_quotes = false;
 
 	if (idtok->type == JSMN_STRING) {
-		if (add_quotes)
+		if (new_id_is_str)
 			add_quotes = false;
 		else
 			offset = 1;
+	} else {
+		if (new_id_is_str)
+			add_quotes = true;
 	}
 
 	json_stream_append(stream, buffer + toks->start,
@@ -1063,7 +1067,7 @@ static void plugin_rpcmethod_cb(const char *buffer,
 
 	response = json_stream_raw_for_cmd(cmd);
 	json_stream_forward_change_id(response, buffer, toks, idtok, cmd->id,
-				      false);
+				      cmd->id_is_string);
 	json_stream_double_cr(response);
 	command_raw_complete(cmd, response);
 
@@ -1089,7 +1093,8 @@ static void plugin_notify_cb(const char *buffer,
 	json_add_tok(response, "method", methodtok, buffer);
 	json_stream_append(response, ",\"params\":", strlen(",\"params\":"));
 	json_stream_forward_change_id(response, buffer,
-				      paramtoks, idtok, cmd->id, false);
+				      paramtoks, idtok, cmd->id,
+				      cmd->id_is_string);
 	json_object_end(response);
 
 	json_stream_double_cr(response);

tests/test_misc.py

@@ -874,7 +874,7 @@ def test_cli(node_factory):
     assert 'help [command]\n    List available commands, or give verbose help on one {command}' in out
 
     # Check JSON id is as expected
-    l1.daemon.wait_for_log("jsonrpc#[0-9]*: IN:id=\"cli:help#[0-9]*")
+    l1.daemon.wait_for_log("jsonrpc#[0-9]*: IN:id=cli:help#[0-9]*")
 
     # Test JSON output.
     out = subprocess.check_output(['cli/lightning-cli',