# Objective

- Fixes #62923.
- When `gutter.git_gutter_width` is set to a small `Custom` value (e.g.
`{"custom": 6.0}`), the deleted-line marker becomes disproportionately
small. It is nearly invisible in the reporter's screenshots, while
added/modified markers scale acceptably.

## Solution

- The deleted marker's `Default` arm uses a `0.35 * line_height` base;
the strip's `Default` arm uses `0.275 * line_height`. That 27% larger
base is what keeps the pill-shaped deleted marker visible next to the
rectangular added/modified strips.
- The `Custom(N)` arm previously used `N` for both branches, dropping
the boost. This PR routes the deleted-empty case through a new
`deleted_marker_base_width(setting, line_height)` helper that applies a
single `DELETED_MARKER_WIDTH_RATIO = 0.35 / 0.275` constant to both
arms.
- Default-mode pixels are byte-identical because `floor(0.275 * lh *
0.35/0.275)` reduces to `floor(0.35 * lh)`. Custom-mode gains the same
1.273× multiplier the default has always had.

## Testing

- Added a pure `#[test] fn test_deleted_marker_base_width` covering
three invariants:
- `Default` at `line_height = 22.0` returns `7px`, identical to the
previous default arm.
- `Custom(6.0)` at `line_height = 22.0` returns a width greater than 6.0
(visibility preserved).
- `Custom(0.0)` returns `0.0`, so the width-0 render path is unchanged.
- Verified locally on Windows: `cargo fmt --all -- --check`, `cargo
check -p editor`, and `cargo clippy -p editor --all-targets -- -D
warnings` all exit 0.
- I have not visually verified the rendered marker on macOS or Linux. A
reviewer with the reporter's setup (`git_gutter_width: {"custom": 6.0}`
on macOS) can confirm the pill stays visible.

## Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content adheres to Zed's UI standards
([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
and
[icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md)
guidelines)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

---

Release Notes:

- Fixed the deleted git-gutter marker becoming nearly invisible when
`git_gutter_width` is set to a small custom pixel value.