ifc-lite-geometry 10.5.0

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.
use super::{embedded_raster_dimensions, raster_image_dimensions};
#[test]
fn issue_4243_budget_headers_before_decoding_pixels() {
    let mut bytes = Vec::new();
    {
        let mut encoder = png::Encoder::new(&mut bytes, 2, 3);
        encoder.set_color(png::ColorType::Rgba);
        let mut writer = encoder.write_header().unwrap();
        writer.write_image_data(&[0; 24]).unwrap();
    }
    let literal = format!("0{}", bytes.iter().map(|b| format!("{b:02X}")).collect::<String>());
    assert_eq!(embedded_raster_dimensions(&literal), Some((2, 3)));
    assert_eq!(raster_image_dimensions(&bytes[..16]), None);
    assert_eq!(embedded_raster_dimensions("0xyz"), None);
    // Reading dimensions must not require the complete compressed pixel stream.
    let jpeg = [0xff,0xd8,0xff,0xc0,0,11,8,0,2,0,3,1,1,0x11,0,0xff,0xda,0,8,1,1,0,0,63,0];
    assert_eq!(raster_image_dimensions(&jpeg), Some((3, 2)));
}

#[test]
fn issue_4243_large_raster_header_is_inspected_without_allocating_its_pixels() {
    let mut bytes = Vec::new();
    { let _writer = png::Encoder::new(&mut bytes, 16_384, 16_384).write_header().unwrap(); }
    bytes.truncate(33); // Keep signature + IHDR, excluding writer-drop IEND.
    // Empty IDAT lets the header reader stop before a missing pixel stream.
    bytes.extend_from_slice(&[0,0,0,0,b'I',b'D',b'A',b'T',0x35,0xaf,0x06,0x1e]);
    assert_eq!(raster_image_dimensions(&bytes), Some((16_384, 16_384)));
}

#[test]
fn issue_4272_header_probe_bounds_encoded_reads_and_skips_pixel_payload() {
    use std::cell::Cell;
    let reads = Cell::new(0usize);
    let mut png = vec![137,80,78,71,13,10,26,10,0,0,0,13,b'I',b'H',b'D',b'R'];
    png.extend_from_slice(&2u32.to_be_bytes());
    png.extend_from_slice(&3u32.to_be_bytes());
    let dimensions = super::super::raster_header::dimensions(usize::MAX, |i| {
        reads.set(reads.get()+1);
        assert!(i < 24, "PNG dimensions must not inspect compressed payload");
        png.get(i).copied()
    });
    assert_eq!(dimensions, Some((2,3)));
    assert!(reads.get() <= 24);
    // A virtual JPEG containing only tiny APP segments must stop at the scan
    // bound without allocating or reading the advertised unbounded remainder.
    let largest = Cell::new(0usize);
    let dimensions = super::super::raster_header::dimensions(usize::MAX, |i| {
        largest.set(largest.get().max(i));
        assert!(i < 1024*1024);
        Some(match i { 0 => 0xff, 1 => 0xd8, _ => [0xff,0xe1,0,2][(i-2)%4] })
    });
    assert_eq!(dimensions, None);
    assert!(largest.get() > 1024*1024-8);
}