pico_graphics is not memory safe

[jondurrant]

frame_buffer is allocated with new but never destroyed even if the pico_graphics object is removed.

[Gadgetoid]

Good spot- MicroPython handles frame_buffer allocation so we've not had much hitting this code path. Looks like, at least, it needs a managed flag and a corresponding delete in the class destructor.

There's also a method to replace the framebuffer, I'm not totally sure if that should be blocked if managed == true or just let the user get themselves into trouble-

pimoroni-pico/libraries/pico_graphics/pico_graphics.cpp

Lines 26 to 28 in 911cbb7

	void PicoGraphics::set_framebuffer(void *frame_buffer) {
	this->frame_buffer = frame_buffer;
	}

[jondurrant]

Yes I moved to create my own buffers to make it memory safe.

I'd really recommend having a full unit test suite for these libraries. Perhaps use CPPUTest which will do the memory safe analysis for you. I have videos and examples of how on YouTube (https://youtu.be/_2-Mh3Kun6s) which might be an accelerator.

[Gadgetoid]

I'd love unit testing across the libraries but I fear it might be an effort of quickly diminishing returns for a project of this scope- it's always been on my to-look-in-to-list though.