ARDUINOJSON_USE_DOUBLE corrupts output

Created by: RAlexeev

I have some problems with #define ARDUINOJSON_USE_DOUBLE 1 macros. See examples below.

pi = 3

In this example I expect to get {"pi":3} instead of two different outputs like {null:3} and {null:0}

#define ARDUINOJSON_USE_DOUBLE 1
#include <ArduinoJson.h>

...

StaticJsonDocument<200> doc;
JsonObject root = doc.to<JsonObject>();
root["pi"] = 3;

serializeJson(doc, Serial);    // {null:3}
Serial.println("");

String jsonStr;
serializeJson(doc, jsonStr);
Serial.println(jsonStr);    // {null:0}

It seems strange that serializeJson(doc, Serial); and serializeJson(doc, jsonStr); Serial.println(jsonStr); produce different results.

If I comment out macros #define ARDUINOJSON_USE_DOUBLE 1, then I'll get correct result {"pi":3} in both type of outputs: serializeJson(doc, Serial); and serializeJson(doc, jsonStr); Serial.println(jsonStr);.

pi = 3.14159265359

In this example I expect to get {"pi":3.141592654} instead of obtained {null:3.141592654} and exception.

#define ARDUINOJSON_USE_DOUBLE 1
#include <ArduinoJson.h>

...

StaticJsonDocument<200> doc;
JsonObject root = doc.to<JsonObject>();
root["pi"] = 3.14159265359;

serializeJson(doc, Serial);    // {null:3.141592654}
Serial.println("");

String jsonStr;
serializeJson(doc, jsonStr);    // Exception (see below)
Serial.println(jsonStr);

Exception (9):
epc1=0x40216e3d epc2=0x00000000 epc3=0x00000000 excvaddr=0x4009220f depc=0x00000000

ctx: cont
sp: 3ffffb20 end: 3fffffd0 offset: 01a0

>>>stack>>>
3ffffcc0:  3ffe8d95 3fff30ac 00000000 00000000
3ffffcd0:  40000000 3ffed650 3ffffe98 40215167
3ffffce0:  3ffe8da4 00000001 3ffe8d91 00000000
3ffffcf0:  3ffe8da4 3ffffe70 3ffffe8c 40215234
3ffffd00:  3ffe002c 3ffffda4 3ffffe8c 4020f09e
3ffffd10:  fffffffe 00000000 3ffffe8c 4020ed9a
3ffffd20:  3ffe8da4 3ffffe70 3ffffe8c 4020f8b1
3ffffd30:  00000000 3ffffd94 3ffffda4 3ffffd94
3ffffd40:  3ffffda4 3ffffd94 400921fb 402143b1
3ffffd50:  3ffffd94 3ffffe74 3ffffe98 402143b1
3ffffd60:  3ffe92e2 3ffffe98 3ffffe8c 4020f0f0
3ffffd70:  3ffffd94 3ffffe74 3ffef828 402145d8
3ffffd80:  3ffe8da4 3ffffe98 3ffef828 402134cb
3ffffd90:  0000000a 40217608 3ffffda4 000000c8
3ffffda0:  00000020 0000000a 00000000 54442eea
3ffffdb0:  400921fb 00000000 00000000 3ffe9361
3ffffdc0:  00000000 40214dd7 0000010a 3ffef968
3ffffdd0:  00000010 00000010 00000000 40100579
3ffffde0:  00000010 40214dd7 00000000 3ffef67c
3ffffdf0:  00000010 3fff1a8c 3fff1a8c 40214dd7
3ffffe00:  3ffe8da4 00000000 3fff1a8c 40214e23
3ffffe10:  00000010 00000010 3fff1a8c 40214e55
3ffffe20:  3ffe8da4 3fff1a80 3fff1a8c 40214ea2
3ffffe30:  3ffe8da4 40215840 0000001c 401004e8
3ffffe40:  3fff2144 4020c139 3ffe8da4 4020bf38
3ffffe50:  00000010 3fff1a80 3ffef5d0 3ffef968
3ffffe60:  00000010 00000010 00000000 40100579
3ffffe70:  00000009 3ffffda4 3ffffda4 3ffef968
3ffffe80:  3ffffd94 3ffffe70 00000000 3ffffeac
3ffffe90:  00000003 40214dd7 3fff1e04 0000000f
3ffffea0:  00000008 3ffffd94 3ffffe74 3ffffe98
3ffffeb0:  3ffffe70 00000394 00000394 4010020c
3ffffec0:  00000001 00000001 3fffff00 4020bb0c
3ffffed0:  00000001 00000001 3fff19ec 40216f7e
3ffffee0:  00000000 00000000 3fff19ec 4020bb02
3ffffef0:  3fff19ec 3ffef614 3fffff20 4020bb3e
3fffff00:  00000000 00000000 00000000 40214f80
3fffff10:  3fff19ec 3ffef614 3ffef5d0 4020bbc5
3fffff20:  3fff2174 0000000f 00000007 00000000
3fffff30:  00000000 4bc6a7f0 0000979b 3ffef8e8
3fffff40:  3ffef614 00000001 3ffe85dc 3ffef5f8
3fffff50:  00000001 00000000 4020aeb4 0000000d
3fffff60:  00000000 3fff1dcc 3ffef5d0 3ffef8e8
3fffff70:  00000001 3ffef5f8 3ffef5d0 4020be00
3fffff80:  402174e8 00000000 00001388 40213868
3fffff90:  00000000 3fff1dcc 40216f88 40216f74
3fffffa0:  3fffdad0 00000000 3ffef8e0 4021388a
3fffffb0:  3fffdad0 00000000 3ffef8e0 402159c0
3fffffc0:  feefeffe feefeffe 3ffe85dc 40100721
<<<stack<<<

 ets Jan  8 2013,rst cause:2, boot mode:(3,0)

load 0x4010f000, len 1384, room 16
tail 8
chksum 0x2d
csum 0x2d
vbb28d4a3
~ld

If I comment out macros #define ARDUINOJSON_USE_DOUBLE 1, then I'll get correct result {"pi":3.141593} in both type of outputs: serializeJson(doc, Serial); and serializeJson(doc, jsonStr); Serial.println(jsonStr);.

pi = "3.14159265359"

In this example I expect to get {"pi":"3.14159265359"} instead of two different outputs like {null:"3.14159265359"} and {null:null}

#define ARDUINOJSON_USE_DOUBLE 1
#include <ArduinoJson.h>

...

StaticJsonDocument<200> doc;
JsonObject root = doc.to<JsonObject>();
root["pi"] = "3.14159265359";

serializeJson(doc, Serial);    // {null:"3.14159265359"}
Serial.println("");

String jsonStr;
serializeJson(doc, jsonStr);
Serial.println(jsonStr);    // {null:null}

If I comment out macros #define ARDUINOJSON_USE_DOUBLE 1, then I'll get correct result {"pi":"3.14159265359"} in both type of outputs: serializeJson(doc, Serial); and serializeJson(doc, jsonStr); Serial.println(jsonStr);.

I use ArduinoJson 6.4.0-beta and compile program by Platformio IDE 1.1.1 with the following settings:

platform = https://github.com/platformio/platform-espressif8266.git#v1.8.0
board = esp12e
framework = arduino