Possible memory leak when receiving

[fredmaria]

Hi,
I think there may be a memory leak in EsPiLight.
(I'm not an expert developer, so it could well be some kind of user error...)
Here's a minimal code sample illustrating the problem I've encountered:

#include <ESPiLight.h>
#define RECEIVER_PIN 14 // any intterupt able pin
#define TRANSMITTER_PIN -1

ESPiLight rf(TRANSMITTER_PIN);

void rfCallback(const String &protocol, const String &message, int status,
size_t repeats, const String &deviceID)
{
Serial.printf("loop heap size: %u\n", ESP.getFreeHeap());
}

void setup()
{
Serial.begin(115200);
Serial.println("Booting");
rf.setCallback(rfCallback);
rf.initReceiver(RECEIVER_PIN);
}

void loop()
{
rf.loop();
}

And here's the corresponding output:
15:16:55.473 -> loop heap size: 31496
15:17:41.075 -> loop heap size: 31136
15:17:41.174 -> loop heap size: 30776
15:17:41.240 -> loop heap size: 30416

........

15:22:57.536 -> loop heap size: 1256
15:23:33.932 -> loop heap size: 896
15:23:33.999 -> loop heap size: 536
15:23:34.065 -> loop heap size: 176
15:23:34.164 -> Out of memory.
15:23:34.164 -> EXIT: 1

The free heap size is decreasing until the microcontroller crashes.

In my case I'm using a nodemcu esp8266.
I'm using Atom/PlatformIO.