InsufficientMemory error while trying to decode

[negezor]

This happens in random pngs, like this

Expected

Decoded png

Actual behaviour

Err(Limits(LimitError { kind: InsufficientMemory }))

Reproduction steps

Repository

use std::io::Read;

fn main() {
    let path_to_file = "./broken.png";

    let mut f = std::fs::File::open(path_to_file).expect("no file found");
    let metadata = std::fs::metadata(&path_to_file).expect("unable to read metadata");
    let mut buffer = vec![0; metadata.len() as usize];
    f.read(&mut buffer).expect("buffer overflow");

    let format = image::guess_format(&buffer).unwrap();

    let mut reader = image::io::Reader::with_format(std::io::Cursor::new(buffer), format);

    reader.no_limits();

    let im = reader.decode().unwrap();
}

[pm4rcin]

I also have that bug. Here's more info with wallpapers that fail https://github.com/danyspin97/wpaperd/issues/21#issue-1393401394

[danyspin97]

This issue hasn't been fixed, please reopen.

[fintelia]

I looked into this some more. Seems that the original image contains an 18MB (!) text chunk before the image data, and the png crate has a hardcoded limit for such chunks.

So, most large but "normal" PNGs should work with the new limits support, but unfortunately more work is required to handle this specific case

[pm4rcin]

@fintelia the issue was resolved https://github.com/danyspin97/wpaperd/issues/21#issuecomment-1994461074 and it works now.