Prevent passing NULL buffer to sendto() for better compatibility with C standard libraries #792

	name: Build and test
	on:
	push:
	branches:
	- master
	pull_request:
	jobs:
	build-linux:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: install packages
	run: sudo apt update && sudo apt install nettle-dev clang-tidy
	- name: cmake
	run: cmake -B build -DUSE_NETTLE=1 -DWARNINGS_AS_ERRORS=1 -DCLANG_TIDY=ON
	- name: make
	run: (cd build; make)
	- name: test
	run: ./build/tests
	build-macos:
	runs-on: macos-latest
	steps:
	- uses: actions/checkout@v2
	- name: cmake
	run: cmake -B build -DWARNINGS_AS_ERRORS=1 -DENABLE_LOCAL_ADDRESS_TRANSLATION=1
	- name: make
	run: (cd build; make)
	- name: test
	run: ./build/tests
	build-windows:
	runs-on: windows-latest
	steps:
	- uses: actions/checkout@v2
	- uses: ilammy/msvc-dev-cmd@v1
	- name: cmake
	run: cmake -B build -G "NMake Makefiles" -DWARNINGS_AS_ERRORS=1
	- name: nmake
	run: \|
	cd build
	nmake
	- name: test
	run: build/tests.exe

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