João Soares
aa63f8e901
## Context `TerminalBounds::num_lines()` uses `floor(height / line_height)` to compute the terminal grid row count. When the height is derived from `N * line_height` (as it is for inline/embedded terminals in the Agent Panel), IEEE 754 float32 arithmetic can produce `N - epsilon` instead of `N`, causing `floor()` to return `N - 1`. This makes the terminal grid one row too small, leaving the first line of output in invisible scrollback (since `display_offset = 0`). The same issue applies to `num_columns()`. The fix adds a small tolerance (`0.01`) before flooring, which absorbs float precision errors without affecting genuine fractional results. Closes #51609 ## How to Review Small PR — focus on the tolerance value (`0.01`) in `num_lines()` and `num_columns()` in `crates/terminal/src/terminal.rs`. The two new tests (`test_num_lines_float_precision`, `test_num_columns_float_precision`) verify the fix across 1,000+ float combinations that previously triggered the bug. ## Self-Review Checklist - [x] I've reviewed my own diff for quality, security, and reliability - [ ] Unsafe blocks (if any) have justifying comments - [ ] The content is consistent with the [UI/UX checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist) - [x] Tests cover the new/changed behavior - [x] Performance impact has been considered and is acceptable Release Notes: - Fixed the first line of terminal output sometimes missing in Agent Panel terminal blocks.
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 issue)
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 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.