# Objective

Fixes #58736

Pause the debugger on a breakpoint, switch your theme, and the active
debug line keeps its old highlight color until you step again or restart
Zed.

## Solution

The highlight stores a concrete color grabbed from the theme back when
`go_to_active_debug_line` ran. A theme switch goes through
`theme_changed`, which refreshes brackets, semantic tokens, and outline
symbols but never re-applies that highlight, so it stays stale.
Re-running `go_to_active_debug_line` from `theme_changed` re-resolves
the color against the current theme.

## Testing

Added a regression test in `debugger_ui` that stops at a debug line,
swaps the theme's `editor.debugger_active_line.background`, and checks
the highlight follows. It fails on `main` and passes with the fix.

Also tested by hand on Windows: started a debugpy session, paused at a
breakpoint, switched themes from the theme selector, and watched the
active line recolor live without stepping or restarting.

## Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [ ] 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

## Showcase

Paused at a breakpoint, switching themes from the theme selector.

| Before | After |
| --- | --- |
|
https://github.com/user-attachments/assets/653a7e1b-3a99-4316-b1c9-b16ed7a7a8ba
|
https://github.com/user-attachments/assets/22a4c876-30f2-44c5-aad9-0f860639074c
|

---

Release Notes:

- Fixed the active debug line color not updating when switching themes
while the debugger is paused
([#58736](https://github.com/zed-industries/zed/issues/58736)).

---------

Co-authored-by: dino <dinojoaocosta@gmail.com>