The libc C standard library memcpy function is very fast, but because of that also very dumb and with a list of circumstances where its behaviour is undefined (a great opportunity to introduce vulnerabilities in your code). The specs of those are in [Wayback/Archive] memcpy, memcpy_s – cppreference.com, including:
The behavior is undefined if either
destorsrcis an invalid or null pointer.
With C compilers becoming smarter and smarter, their optimisations can hide the fact that you call memcpy with parameters causing undefined behaviour.
This is a nice example of that: [Wayback/Archive] Fix a crash trying to save an empty AudioStream by hpvb · Pull Request #100422 · godotengine/godot · GitHub
The change is relatively simple, but hardly shows why the change is there. Only one line got changed in [Wayback/Archive] Fix a crash trying to save an empty AudioStream by hpvb · Pull Request #100422 · godotengine/godot · GitHub
The Wiert Corner - irregular stream of stuff 