Tokio async flush stuck with big files

[davxy]

Summary

The async flush hangs it the file lenght is greater than ~1M.

In particular this async call never returns:

helix/helix-view/src/document.rs

Line 318 in 661f48d

writer.flush().await?;

Reproducible creating a "big enough file" and exiting the editor with :wq.

After some tests I was able to find out the exact amount of bytes required to get the flush stuck.
This value (on machine) is exactly : 1,030,385 bytes

Note: the bug doesn't trigger if a write and quit in two separate actions.

Reproduction Steps

1. Create a file big enough (1040385 bytes on my machine)

tr -dc A-Za-z0-9 < /dev/random | head -c 1040385 > test.txt

2. Open it in Helix.
3. Hit :wq in normal mode to exit

Platform

Linux

Terminal Emulator

Alacritty

Helix Version

helix 22.08.1 (66276ce)

[Ordoviz]

1040385 is exactly the amount of bytes that causes #3975, which will be fixed by #2267.

[the-mikedavis]

Duplicate of #3975