---
id: 3aeb0d21-a690-4369-82a2-cd7e75037ec7
title: 'diff: added lines starting +++/--- are misclassified as file headers'
state: closed
labels:
- ui
assignees: []
milestone: null
created: 2026-10-27T17:24:52.458393633Z
updated: 2026-10-27T17:45:41.728512111Z
---
## What

Diff lines are classified purely by prefix:

- added line whose **content** starts with `+++` → rendered `++++ …` and treated as a file header
- added line whose content starts with `---` → `+--- …` (this one is counted, but a removed line `---- …` is misclassified)

`src/layout.rs:109-127`: `line.starts_with("+++")` / `starts_with("---")` before the add/remove branches.

## Reproduced

Append four lines to a tracked file: `+++ not a header`, `--- not a header`, `@@ not a hunk`, `prefix+++line`. The commit page reports **+3** (4 actual added) and the `++++ not a header` row is styled as a file header; subsequent new-side line numbers are off by one.

## Impact

Wrong diffstat and line numbers; a reviewer can be misled about what changed (content can hide from the count).

## Fix

Use diff position: `+++`/`---` are headers only before the first `@@` hunk (and `+++` after `---`); otherwise classify by the leading marker. Or require the `a/`/`b/` prefix for headers. Add a fixture test for content that starts with `+++`/`---`/`@@`.