Kirill Bulatov
e6efd6fddc
Follow-up to https://github.com/zed-industries/zed/pull/60721 Before: <img width="564" height="470" alt="before" src="https://github.com/user-attachments/assets/d825464d-f8d9-4fa1-bee3-42b5f615d4ba" /> <img width="745" height="221" alt="image" src="https://github.com/user-attachments/assets/18139bec-6778-491a-9aa5-0112bd121723" /> After: <img width="576" height="472" alt="after" src="https://github.com/user-attachments/assets/4c3c37cf-12c4-421e-98e9-cc6e40aa099d" /> <img width="812" height="275" alt="image" src="https://github.com/user-attachments/assets/407e06b4-101f-4984-8d5b-4e33895b5ae9" /> ### Bug 1 — constraint-blind text layout cache (the collapse) `TextLayout`'s measure closure is stateful (each call overwrites the shared element state used for painting), and its cache check served cached sizes to unconstrained probes regardless of the constraints they were computed under: 1. `uniform_list::measure_item` lays an item out at `(MinContent, MinContent)`; the row's `min_w_0` lets it shrink to ~0, so labels get truncated at a tiny width — and that tiny size lands in the element state. 2. The real layout probes the label's flex base size with `available_space.width = MaxContent` (taffy maps Definite → MaxContent). Truncated labels are `whitespace_nowrap`, so both `wrap_width` and `truncate_width` were `None` → the cache check passed → the poisoned tiny size became the flex basis → labels rendered at ~5 chars. **Fix**: record `truncate_width` in `TextLayoutInner` and never serve a cached layout that was computed *with* truncation to an unconstrained probe; the honest intrinsic size is recomputed instead, and the final `PerformLayout` call re-truncates against the real resolved width. ### Bug 2 — truncation width math disagrees with shaping (the ~2-char loss) After fix 1, rows got their full width, but exact-fit strings like `Cargo.toml` still lost ~2 chars: - Sizing measures via `shape_text` (real shaping with kerning); the element gets exactly `ceil(shaped_width)`. - The truncation decision (`LineWrapper::should_truncate_line_middle` etc.) sums **per-character advances** — no kerning — with zero tolerance, overestimating width for some glyph sequences. Text sitting in a box of exactly its own measured width got truncated, losing ~2 chars to fit the `…`. String-dependent (kerning pairs), hence `Cargo.toml` broke while `Cargo.lock` didn't. - Previously masked because taffy 0.10 usually skipped the final measure invocation, so the truncation path rarely ran with an exact-fit width. **Fix**: before truncating (nowrap case, `wrap_width.is_none()`), shape the untruncated text and skip truncation if the *shaped* width fits — matching CSS `text-overflow`, which only activates on actual overflow. Cheap: the shaping result is a `line_layout_cache` hit from the earlier untruncated sizing probe. ### Bug 3 — `MinContent` used instead of `MaxContent` that caused over truncation of certain labels Release Notes: - N/A
Zed
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:
- Web (tracking discussion)
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
Zed source code is licensed primarily under GPL-3.0-or-later, with Apache-2.0 components where marked.
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 specifiederror for a crate you've created? If so, addpublish = falseunder[package]in your crate's Cargo.toml. - Is the error
failed to satisfy license requirementsfor 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 theacceptedarray inscript/licenses/zed-licenses.toml. - Is
cargo-aboutunable to find the license for a dependency? If so, add a clarification field at the end ofscript/licenses/zed-licenses.toml, as specified in the cargo-about book.
Sponsorship
Zed is developed by Zed Industries, Inc., a for-profit company.
If you’d like to financially support the project, you can do so via GitHub Sponsors. Sponsorships go directly to Zed Industries and are used as general company revenue. There are no perks or entitlements associated with sponsorship.