get<String> returns "-0" for 0

Created by: RAlexeev

get<String> returns different outputs of 0 for v6.3.0-beta and v6.2.3-beta. In case of v6.3.0-beta it returns "-0" (minus occurs before 0), but in case of v6.2.3-beta it returns "0".

Example:

char json[] = "{\"x\":0}";
StaticJsonDocument<256> doc;
deserializeJson(doc, json);
JsonObject object = doc.as<JsonObject>();
obj["x_str"] = object.get<String>("x");
obj["x_uint"] = object.get<unsigned int>("x");

Output in case of v6.3.0-beta:

x_str = "-0"
x_uint = 0

Output in case of v6.2.3-beta:

x_str = "0"
x_uint = 0

I use Platformio IDE 1.1.1 with the following settings:

platform = https://github.com/platformio/platform-espressif8266.git#v1.8.0
board = esp_wroom_02
framework = arduino