Ichimura Tomoo 81463223d5 Support opening and saving files with legacy encodings (#44819)
## Summary

Addresses #16965

This PR adds support for **opening and saving** files with legacy
encodings (non-UTF-8).
Previously, Zed failed to open files encoded in Shift-JIS, EUC-JP, Big5,
etc., displaying a "Could not open file" error screen. This PR
implements automatic encoding detection upon opening and ensures the
original encoding is preserved when saving.

## Implementation Details

1.  **Worktree (Loading)**:
* Updated `load_file` to use `chardetng` for automatic encoding
detection.
* Files are decoded to UTF-8 internal strings for editing, while
preserving the detected `Encoding` metadata.
2.  **Language / Buffer**:
* Added an `encoding` field to the `Buffer` struct to store the detected
encoding.
3.  **Worktree (Saving)**:
    * Updated `write_file` to accept the stored encoding.
    * **Performance Optimization**:
* **UTF-8 Path**: Uses the existing optimized `fs.save` (streaming
chunks directly from Rope), ensuring no performance regression for the
vast majority of files.
* **Legacy Encoding Path**: Implemented a fallback that converts the
Rope to a contiguous `String/Bytes` in memory, re-encodes it to the
target format (e.g., Shift-JIS), and writes it to disk.
* *Note*: This fallback involves memory allocation, but it is necessary
to support legacy encodings without refactoring the `fs` crate's
streaming interfaces.

## Changes

- `crates/worktree`:
    - Add dependencies: `encoding_rs`, `chardetng`.
    - Update `load_file` to detect encoding and decode content.
    - Update `write_file` to handle re-encoding on save.
- `crates/language`: Add `encoding` field and accessors to `Buffer`.
- `crates/project`: Pass encoding information between Worktree and
Buffer.
- `crates/vim`: Update `:w` command to use the new `write_file`
signature.

## Verification

I validated this manually using a Rust script to generate test files
with various encodings.

**Results:**

*  **Success (Opened & Saved correctly):**
    * **Japanese:** `Shift-JIS` (CP932), `EUC-JP`, `ISO-2022-JP`
    * **Chinese:** `Big5` (Traditional), `GBK/GB2312` (Simplified)
* **Western/Unicode:** `Windows-1252` (CP1252), `UTF-16LE`, `UTF-16BE`
* ⚠️ **limitations (Detection accuracy):**
* Some specific encodings like `KOI8-R` or generic `Latin1` (ISO-8859-1)
may partially display replacement characters (`?`) depending on the file
content length. This is a known limitation of the heuristic detection
library (`chardetng`) rather than the saving logic.


Release Notes:

- Added support for opening and saving files with legacy encodings
(Shift-JIS, Big5, etc.)

---------

Co-authored-by: CrazyboyQCD <53971641+CrazyboyQCD@users.noreply.github.com>
Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>
2025-12-17 19:46:17 +00:00
2025-10-21 09:58:26 +02:00
2025-10-17 18:49:11 +02:00
2025-12-15 11:51:18 +00:00
2025-09-23 16:49:45 +00:00
2025-12-15 22:19:18 -07:00
2025-12-17 16:14:57 +00:00
2025-10-27 13:27:59 -04:00
WIP
2023-12-14 09:25:14 -07:00
2025-03-10 01:06:11 -07:00
2024-09-30 17:46:21 -04:00
2025-12-17 01:42:04 +01:00
2025-02-04 09:02:59 -05:00
2025-02-04 09:02:59 -05:00
2025-10-27 13:27:59 -04:00
2025-10-17 18:58:14 +00:00
2025-03-10 01:06:11 -07:00

Zed

Zed CI

Welcome to Zed, a high-performance, multiplayer code editor from the creators of Atom and Tree-sitter.


Installation

On macOS, Linux, and Windows you can download Zed directly or install Zed via your local package manager (macOS/Linux/Windows).

Other platforms are not yet available:

Developing Zed

Contributing

See CONTRIBUTING.md for ways you can contribute to Zed.

Also... we're hiring! Check out our jobs page for open roles.

Licensing

License information for third party dependencies must be correctly provided for CI to pass.

We use cargo-about to automatically comply with open source licenses. If CI is failing, check the following:

  • Is it showing a no license specified error for a crate you've created? If so, add publish = false under [package] in your crate's Cargo.toml.
  • Is the error failed to satisfy license requirements for a dependency? If so, first determine what license the project has and whether this system is sufficient to comply with this license's requirements. If you're unsure, ask a lawyer. Once you've verified that this system is acceptable add the license's SPDX identifier to the accepted array in script/licenses/zed-licenses.toml.
  • Is cargo-about unable to find the license for a dependency? If so, add a clarification field at the end of script/licenses/zed-licenses.toml, as specified in the cargo-about book.
Description
Code at the speed of thought – Zed is a high-performance, multiplayer code editor from the creators of Atom and Tree-sitter.
Readme 586 MiB
Languages
Rust 94.7%
JSON-with-Comments 3.1%
Inno Setup 0.6%
Scheme 0.5%
Shell 0.3%
Other 0.4%