EDIT: Adding a STRING Properties without Setting it's value at Setup() Crashes the ESP32

[jcherrabi]

Hello there,
i added the following line to the AsyncProperty.ino example
ThingProperty text2("text2", "", STRING, nullptr, textChanged);

and in the setup() i added this:
textDisplay.addProperty(&text2);

Compile and run.. next add the thing using the + on the gateway interface, everything is fine so far now remove the added thing and try to add again and voila the ESP crashes and reboots... if i change the newly added property to BOOLEAN for example then it doesn't crash.

decoding the stack reveals this:
`PC: 0x4015691f: String::buffer() const at C:\Users\xxxx\AppData\Local\Arduino15\packages\esp32\hardware\esp32\1.0.6\cores\esp32/WString.h line 318
EXCVADDR: 0x00000008

Decoding stack results
0x4015691f: String::buffer() const at C:\Users\xxxx\AppData\Local\Arduino15\packages\esp32\hardware\esp32\1.0.6\cores\esp32/WString.h line 318
0x400d43da: ArduinoJson6180_D1::VariantData::storeString (ArduinoJson6180_D1::ArduinoStringAdapter, ArduinoJson6180_D1::MemoryPool*, ArduinoJson6180_D1::storage_policies::store_by_copy) at C:\Users\xxxx\AppData\Local\Arduino15\packages\esp32\hardware\esp32\1.0.6\cores\esp32/WString.h line 230
0x400d443f: ArduinoJson6180_D1::Converter ::toJson(String const&, ArduinoJson6180_D1::VariantRef) at C:\Users\xxxx\Documents\Arduino\libraries\ArduinoJson\src/ArduinoJson/Variant/VariantData.hpp line 238
0x400d4a1d: ThingItem::serializeValue(ArduinoJson6180_D1::ObjectRef) at C:\Users\xxxx\Documents\Arduino\libraries\ArduinoJson\src/ArduinoJson/Variant/VariantRef.hpp line 88
0x400d7e63: WebThingAdapter::handleThingPropertyGet(AsyncWebServerRequest*, ThingItem*) at C:\Users\xxxx\Documents\Arduino\libraries\webthing-arduino/ESPWebThingAdapter.h line 403
0x401567c2: std::_Function_handler (WebThingAdapter*, std::_Placeholder1>, ThingProperty*)> >::_M_invoke(std::_Any_data const&, AsyncWebServerRequest*&&) at c:\users\xxxx\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\1.22.0-97-gc752ad5-5.2.0\xtensa-esp32-elf\include\c++\5.2.0/functional line 600
0x400de8a1: AsyncCallbackWebHandler::handleRequest(AsyncWebServerRequest*) at c:\users\xxxx\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\1.22.0-97-gc752ad5-5.2.0\xtensa-esp32-elf\include\c++\5.2.0/functional line 2271
0x400dc6ed: AsyncWebServerRequest::_parseLine() at C:\Users\xxxx\Documents\Arduino\libraries\ESPAsyncWebServer\src\WebRequest.cpp line 581
0x400dc7b1: AsyncWebServerRequest::_onData(void*, unsigned int) at C:\Users\xxxx\Documents\Arduino\libraries\ESPAsyncWebServer\src\WebRequest.cpp line 123
0x400dca01: std::_Function_handler >::_M_invoke(const std::_Any_data &, , , , ) at C:\Users\xxxx\Documents\Arduino\libraries\ESPAsyncWebServer\src\WebRequest.cpp line 76
0x400e06d1: AsyncClient::_recv(tcp_pcb*, pbuf*, signed char) at c:\users\xxxx\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\1.22.0-97-gc752ad5-5.2.0\xtensa-esp32-elf\include\c++\5.2.0/functional line 2271
0x400e0751: AsyncClient::_s_recv(void*, tcp_pcb*, pbuf*, signed char) at C:\Users\xxxx\Documents\Arduino\libraries\AsyncTCP\src\AsyncTCP.cpp line 1191
0x400e0d4e: _async_service_task(void*) at C:\Users\xxxx\Documents\Arduino\libraries\AsyncTCP\src\AsyncTCP.cpp line 159
0x40089792: vPortTaskWrapper at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/port.c line 143`

[jcherrabi]

Hello again,
the problem was tracked to the following:

if you add a STRING property without setting its value in the Setup() it will crash.... as a workaround to prevent the crashing one MUST call the setValue() before addProperty in the setup() as follow:

ThingPropertyValue genericValue;

genericValue.string = "Some message";

textDisplay.setValue(genericValue);

textDisplay.addProperty(&text2);

basically this must be treated and fixed in the upcoming version to check if the value is null before trying to read it's value...

Cheers,
Jay