Panic when reading empty stream

[ok-nick]

Repro:

use std::io::{self, Cursor};

use c2pa::{Builder, Reader, Result};

mod common;
use common::test_signer;

#[test]
fn test_builder_read() -> Result<()> {
    let manifest_def = include_str!("../tests/fixtures/simple_manifest.json");
    let mut source = Cursor::new(include_bytes!("fixtures/sample1.svg"));
    let format = "image/svg+xml";

    let mut builder = Builder::from_json(manifest_def)?;
    let manifest_bytes = builder.sign(&test_signer(), format, &mut source, &mut io::empty())?;

    Reader::from_manifest_data_and_stream(&manifest_bytes, format, Cursor::new(vec![]))?;

    Ok(())
}

Error:

thread 'test_builder_read' panicked at sdk/src/utils/hash_utils.rs:247:28:
attempt to subtract with overflow

[github-jira-sync-bot]

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[github-jira-sync-bot]

:white_check_mark: Jira issue https://jira.corp.adobe.com/browse/CAI-6194 is successfully created for this GitHub issue.

[Coolkaba]

Repro:

use std::io::{self, Cursor};

use c2pa::{Builder, Reader, Result};

mod common;
use common::test_signer;

#[test]
fn test_builder_read() -> Result<()> {
    let manifest_def = include_str!("../tests/fixtures/simple_manifest.json");
    let mut source = Cursor::new(include_bytes!("fixtures/sample1.svg"));
    let format = "image/svg+xml";

    let mut builder = Builder::from_json(manifest_def)?;
    let manifest_bytes = builder.sign(&test_signer(), format, &mut source, &mut io::empty())?;

    Reader::from_manifest_data_and_stream(&manifest_bytes, format, Cursor::new(vec![]))?;

    Ok(())
}

Error:

thread 'test_builder_read' panicked at sdk/src/utils/hash_utils.rs:247:28:
attempt to subtract with overflow

thread 'test_builder_read' panicked at sdk/src/utils/hash_utils.rs:247:28: attempt to subtract with overflow

[ok-nick]

Fixed in #529