Line not displayed when first span character is a line feed

[Volham22]

Hello,

Thanks for all your work on this project!

Problem

I recently discovered an issue while using annotate_snippets version 0.11.3 with the following code:

    let message = Level::Error.title("dummy").snippet(
        Snippet::source(
            r"foo
bar
baz
            ",
        )
        .fold(true)
        .annotation(Level::Error.span(4..11)),
    );
    let renderer = Renderer::styled();
    anstream::println!("{}", renderer.render(message));

test.txt

foo
bar
baz

The problem is that when a span starts with a line feed (\n), the entire following line isn't annotated and is sort of ignored. We can clearly see in the output below that the annotation is somehow truncated. While this isn't a blocking problem for us, we wanted to share our finding as this looks like a bug.

Actual output

This code produces the following output:

$ cargo r
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/error_message_tests`
error: dummy
  |
3 | | baz
  | |___^
  |

Expected output

We can get the following output by moving the annotation's span to the previous byte (3..11).

$ cargo r
   Compiling error_message_tests v0.1.0 (/home/machu/work/error_message_tests)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.18s
     Running `target/debug/error_message_tests`
error: dummy
  |
1 |   foo
  |  ____^
2 | | bar
3 | | baz
  | |___^
  |

Thanks for your time!

[Muscraft]

This was fixed in #131, but I would like to note the output is a little different than you had expected:

#[test]
fn issue_130() {
    let input = Level::Error.title("dummy").snippet(
        Snippet::source("foo\nbar\nbaz")
            .origin("file/path")
            .line_start(3)
            .fold(true)
            .annotation(Level::Error.span(4..11)), // bar\nbaz
    );

    let expected = str![[r#"
error: dummy
 --> file/path:4:1
  |
4 | / bar
5 | | baz
  | |___^
  |
"#]];
    let renderer = Renderer::plain();
    assert_data_eq!(renderer.render(input).to_string(), expected);
}