Unsound Pod implementation in released crate (not on main)

[Manishearth]

https://docs.rs/rgb/0.8.53/rgb/struct.Rgba.html#impl-Pod-for-Rgba%3CT,+A%3E

This impl is unsound: if T != A there can be padding bytes.

This is fixed on main, though.

rust-rgb/src/bytemuck_impl.rs

Lines 5 to 6 in 7915bd4

	unsafe impl<T: ::bytemuck::Zeroable> ::bytemuck::Zeroable for $name<T> {}
	unsafe impl<T: ::bytemuck::Pod> ::bytemuck::Pod for $name<T> {}

Miri repro:

use rgb::RGBA;

fn main() {
    let pixel = RGBA { r: 1u8, g: 2u8, b: 3u8, a: 4u16 };
    let bytes = bytemuck::bytes_of(&pixel);
    let _ub = bytes[3];
}

error: Undefined Behavior: reading memory at alloc107[0x3..0x4], but memory is uninitialized at [0x3..0x4], and this operation requires initialized memory
 --> src/bin/repro1.rs:6:15
  |
6 |     let _ub = bytes[3];
  |               ^^^^^^^^ Undefined Behavior occurred here
  |
  = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
  = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

Uninitialized memory occurred at alloc107[0x3..0x4], in this allocation:
alloc107 (stack variable, size: 6, align: 2) {
    01 02 03 __ 04 00                               │ ...░..
}

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to 1 previous error