Systemd is bad parsing
I agree with most of the critique, but I don't quite get the part about the use of assert.The code in question quite clearly doesn't use C's standard assert macro, but a custom macro called assert_return (which I guess checks for a condition, and returns from the function instead of aborting the program).So basically:    if (!condition) {
        return err;
    }

How else would one check for invalid input to the function?