Panic from `print_text`

[samtay]

Someone has observed thread 'main' panicked at 'attempt to subtract with overflow' coming from a skin.print_text call (ref samtay/so#8), and also found that such panic goes away when using skin.print_inline. Unfortunately I couldn't repo this myself, but the relevant details from that issue are:

• OS: Ubuntu 18.04
• Terminal: gnome-terminal
• Terminal size when rendering: (190, 51)
• Relevant part of the stack trace:

  13:     0x55f43543f6ed - core::panicking::panic::h68e56c2eeba99c8c
                             at src/libcore/panicking.rs:50
  14:     0x55f434c96c0d - minimad::compound::Compound::cut_tail::h65a621fcce14ec17
                             at /home/e/.cargo/registry/src/github.com-1ecc6299db9ec823/minimad-0.6.4/src/compound.rs:117
  15:     0x55f434c7062c - termimad::wrap::hard_wrap_composite::ha144c51dfb0493a2
                             at /home/eyehuda/.cargo/registry/src/github.com-1ecc6299db9ec823/termimad-0.8.24/src/wrap.rs:137
  16:     0x55f434c71116 - termimad::wrap::hard_wrap_lines::hcc2fff69ff958a06
                             at /home/eyehuda/.cargo/registry/src/github.com-1ecc6299db9ec823/termimad-0.8.24/src/wrap.rs:172
  17:     0x55f434c72f2e - termimad::text::FmtText::from_text::hdd93418c5a6ceb6b
                             at /home/eyehuda/.cargo/registry/src/github.com-1ecc6299db9ec823/termimad-0.8.24/src/text.rs:44
  18:     0x55f434c72de0 - termimad::text::FmtText::from::h5006d4ececb9711c
                             at /home/eyehuda/.cargo/registry/src/github.com-1ecc6299db9ec823/termimad-0.8.24/src/text.rs:32
  19:     0x55f434c7f0eb - termimad::skin::MadSkin::term_text::hd65d68486384d1a9
                             at /home/eyehuda/.cargo/registry/src/github.com-1ecc6299db9ec823/termimad-0.8.24/src/skin.rs:208
  20:     0x55f434c7f160 - termimad::skin::MadSkin::print_text::h1276bb441ef97417
                             at /home/eyehuda/.cargo/registry/src/github.com-1ecc6299db9ec823/termimad-0.8.24/src/skin.rs:243

• Input causing panic: gist link

Note the markdown input is quite large, so I put it in a gist. I also embedded it within the ./examples/text/main.rs file so that it would be easier to run.

EDIT: I was able to repro this. At terminal width 112 there is no panic. If the terminal width is greater than or equal to 117, you can observe this panic.

I think if you make sure your terminal width is that wide (e.g. go full screen), and run this:

cd /path/to/termimad
curl -o "examples/text/main.rs" "https://gist.githubusercontent.com/samtay/cf9d1b8c0c7935baf6f6971101bd567e/raw/dff5e762f9a56f76aa64e9c61b57311c42c7a0f0/example-panic.rs"
RUST_BACKTRACE=1 cargo run --example text

you should be able to observe it.

[Canop]

I do reproduce it.

Smaller example:

use std::io::Write;
use termimad::*;

static MD: &str = r#"
Note that the "before" code is basically the [implementation of today's `poll_fn` function](https://github.com/rust-lang-nursery/futures-rs/blob/0.3.1/futures-util/src/future/poll_fn.rs#L48-L56)
"#;

fn main() {
    let skin = MadSkin::default();
    skin.print_text(MD);
}

[Canop]

This should have been fixed. Can you please confirm it's OK @samtay ?

[samtay]

Yes, I just tried out master and it's working on my end. Thanks for such a quick fix!