Closes #51011

Before you mark this PR as ready for review, make sure that you have:
- [X] Added a solid test coverage and/or screenshots from doing manual
testing
- [X] Done a self-review taking into account security and performance
aspects
- [X] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- N/A *or* Added/Fixed/Improved ...

I did a search for `/^line_comments = .*[^\s\[]"/` to identify these 3
languages:

- Git Commit
- Go Mod
- Go Work

that don't add/remove a trailing space for inline comments. I couldn't
find any indication that the absence of the trailing space is due to any
peculiarity of these languages.

---

For Git Commit, I should note that (strictly speaking) the comment
character is a single `#` without a trailing space, as Git removes any
line starting with the default comment character (`#`) (see
https://git-scm.com/docs/git-config#Documentation/git-config.txt-corecommentChar).

But I believe this change only affects whether `editor::ToggleComments`
adds/removes the space, and not how the file is syntax highlighted. So
for aesthetics and consistency, it should be better to add/remove the
trailing space.

---

Before you mark this PR as ready for review, make sure that you have:

- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [ ] Done a self-review taking into account security and performance
aspects
- [ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- Add/remove a space when toggling inline comments in Git Commit and Go
Mod/Work languages

This PR adds support for select first & last actions, as I was missing
them badly :).

**Example**:


https://github.com/user-attachments/assets/709037e6-544c-4891-8f48-7808d556a5a2

Before you mark this PR as ready for review, make sure that you have:
- [x] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- N/A

## Summary

This fix addresses the cross-platform root cause identified in issue
#38109 where open buffers go stale or empty when external tools write
files.

## The Problem

The buffer's `file_updated()` method was only comparing `mtime` to
determine if a buffer needed to be reloaded. This caused a race
condition when external tools write files using `std::fs::write()`,
which uses `O_TRUNC` and creates a brief window where the file is 0
bytes:

1. Scanner re-stats → sees 0 bytes, mtime T
2. `file_updated()` sees mtime changed → emits `ReloadNeeded`
3. Buffer reloads to empty, stamps `saved_mtime = T`
4. Tool finishes writing → file has content, but mtime is still T (or
same-second granularity)
5. Scanner re-stats → mtime T matches `saved_mtime` → **no reload
triggered**
6. Buffer permanently stuck empty

## The Fix

Release Notes:

- Add the file `size` to `DiskState::Present`, so that even when mtime
stays the same, size changes (0 → N bytes) will trigger a reload. This
is the same fix that was identified in the issue by @lex00.

## Changes

- `crates/language/src/buffer.rs`: Add `size: u64` to
`DiskState::Present`, add `size()` method
- `crates/worktree/src/worktree.rs`: Pass size when constructing File
and DiskState::Present
- `crates/project/src/buffer_store.rs`: Pass size when constructing File
- `crates/project/src/image_store.rs`: Pass size when constructing File
- `crates/copilot/src/copilot.rs`: Update test mock

## Test plan

- [ ] Open a file in Zed
- [ ] Write to that file from an external tool (e.g., `echo "content" >
file`)
- [ ] Verify the buffer updates correctly without needing to reload

Fixes #38109

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
Co-authored-by: Ben Kunkle <ben.kunkle@gmail.com>
Co-authored-by: Jakub Konka <kubkon@jakubkonka.com>

Closes #ISSUE

Before you mark this PR as ready for review, make sure that you have:
- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [X] Done a self-review taking into account security and performance
aspects
- [ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- Enabled `diff_stats` in the git panel by default.

Release Notes:

- N/A

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>

Closes #48697
Supersedes #48698
Related to #38109

## Problem

If you edit a file and an external tool writes to it while you have
unsaved changes, Zed tracks the new file but skips the reload to
preserve your edits. If you then undo everything, the buffer goes back
to clean but still shows the old content. The disk has moved on, but
nothing triggers a reload.

## Fix

In `did_edit()`, when the buffer transitions from dirty to clean, check
if the file's mtime changed while it was dirty. If so, emit
`ReloadNeeded`. Only fires for files that still exist on disk
(`DiskState::Present`).

7 lines in `crates/language/src/buffer.rs`.

### No double reload

`file_updated()` suppresses `ReloadNeeded` when the buffer is dirty
(that's the whole bug). So by the time `did_edit()` fires on
dirty-to-clean, no prior reload was emitted for this file change. The
two paths are mutually exclusive.

## Test plan

- New: `test_dirty_buffer_reloads_after_undo`
- No regression in `test_buffer_is_dirty` or other buffer tests
- All project integration tests pass
- clippy clean

Release Notes:

- Fixed an issue where buffer content could become stale after undoing
edits when an external tool wrote to the file while the buffer was
dirty.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Ben Kunkle <ben@zed.dev>

This removes the assumption that one project <-> one native agent. The
native agent now maintains a project per session. We don't make use of
this right now, but it will come in handy once we start sharing ACP
connections globally.

Release Notes:

- N/A

Release Notes:

- N/A

Release Notes:

- N/A

BufferEvent::Edited had no way to distinguish local edits from remote
(collaboration) edits. This caused edit prediction behavior to fire on
the guest's editor when the host made document changes.

Release Notes:

- Fixed edit predictions triggering on collaboration guests when the
host edits the document.

---------

Co-authored-by: Ben Kunkle <ben@zed.dev>

Release Notes:

- N/A

This should be the last step in implementing full git worktree support
in the `GitStore`. We still need to add UI for that allows a user to
rename a git worktree and, by extension git branches if we use the git
picker to do so.

Also, I added a helper function called `disallow_guest_request::<T>` to
the `Collab::rpc` that is used to specify a proto request isn't allowed
to be sent by a guest. This enabled me to add a regression test that
checks that a guest isn't allowed to delete a git worktree, without the
test hanging forever because it's waiting for the proto server to
respond.

Since SSH connections send the proto message directly from client to
remote host, this won't affect those requests.

Before you mark this PR as ready for review, make sure that you have:
- [x] Added solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- git: Add SSH support for removing git worktrees

This PR adds a "Resolve with Agent" button in each merge conflict block,
as well as "Resolve Conflicts with Agents" button on a notification for
resolving conflicts across all the files that have any. When clicking on
either of these buttons, the agent panel opens up with a template prompt
auto-submitted. For the first case, the specific content of the merge
block is already attached as context for the agent to act quickly, given
it's a local and small context. For the second case (all conflicts
across the codebase), the prompt just indicates to the agent which files
have conflicts and then it's up for the agent to see them. This felt
like a simpler way to go as opposed to extracting the content for all
merge conflicts across all damaged files.

Here's how the UI looks like:

<img width="550" height="1964" alt="Screenshot 2026-02-21 at 11  04@2x"
src="https://github.com/user-attachments/assets/96815545-ba03-40e5-9cb0-db0ce9588915"
/>

---

Before you mark this PR as ready for review, make sure that you have:
- [x] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- Git: Added the ability to quickly resolve merge conflicts with the
agent.

---------

Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>
Co-authored-by: Zed Zippy <234243425+zed-zippy[bot]@users.noreply.github.com>

Fixes #51048

The "Copy Command" button uses `.visible_on_hover(group)` from GPUI to
only appear when the user hovers over its parent container. In
`render_collapsible_command` (used to render the code blocks for
terminal tool calls like "Run Command"), the parent `v_flex()` container
was missing the `.group()` assignment. This caused the copy button to
never become visible, which became apparent when an agent session was
restored from history.

This commit adds `.group(group.clone())` to the root `v_flex()`
container in `render_collapsible_command` to restore the hover
visibility for the "Copy Command" button.

Video :
[Screencast from 2026-03-10
18-06-57.webm](https://github.com/user-attachments/assets/ae931ac3-c7f1-4044-a3d8-a91a93d9c3bb)
[Screencast from 2026-03-10
18-06-01.webm](https://github.com/user-attachments/assets/5ddb8085-bafe-4e9a-bb02-74e3d860ae1a)

Release Notes:

- Agent: Fixed an issue where the "Copy Command" button would not appear
on hover for terminal tool calls.

This format generates fewer token while maintaining the quality:

```
Model                     Generated tokens ↓    DeltaChrF ↑
0306-seed-multi-regions   46,239                80.62
0304-seed-no-edits        110,871               80.61
0303-seed                 271,457               79.62
```

In addition to the student format, this change adds a new teacher
prompt. It seems to be worse than the original, but I haven't optimized
it at all. Keeping it for now as a base for potential improvements.


Release Notes:

- N/A

Release Notes:

- N/A

Co-authored-by: Piotr Osiewicz <piotr@zed.dev>

Closes #48284

## Summary
- Fix `project_panel::RevealInFileManager` when no project panel entry
is selected.
 - Preserve existing selected entry behavior.
- Add fallback to reveal the last visible worktree root when selection
is empty.
 - Add regression test cov.

## Root Cause
`RevealInFileManager` previously depended on `selected_sub_entry()`.
When selection is cleared (e.g. click project panel background), Command
Palette dispatch had no target and no-op'd.


## Verification
 - `cargo fmt --all -- --check`
 - `./script/check-keymaps`
 - `./script/clippy -p project_panel`
 - `cargo test -p project_panel -- --nocapture`

## Manual Testing
 - Reproduced issue steps from #48284.
- Confirmed Command Palette `Project panel: Reveal in file manager` now
opens project root when selection is empty.
  - Confirmed selected file reveal behavior remains unchanged.
  - Confirmed context menu reveal behavior remains unchanged.

Release Notes:
- Fixed `Project panel: Reveal in file manager` to work even when no
project panel entry is selected.

## Summary
Fixes Windows file-open parsing for names like `main (1).log`.

`PathWithPosition::parse_str` could treat `(1)` in a normal filename as
a position suffix and drop the extension/path tail. The regex is now
anchored so parenthesized row/column parsing only applies at the end of
the filename (with optional trailing `:` and optional range suffix).

## Testing
- `cargo test -p util path_with_position_parse_`

Closes #50597

Release Notes:

- Fixed opening files with names like `main (1).log` on Windows.

This PR makes the "Open Project" button in the sidebar also open the
"Recent Projects" popover, while also anchoring that popover to the the
button on the sidebar instead.

Release Notes:

- N/A

Closes #ISSUE

Before you mark this PR as ready for review, make sure that you have:
- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [ ] Done a self-review taking into account security and performance
aspects
- [ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- N/A *or* Added/Fixed/Improved ...

Release Notes:

- N/A

---------

Co-authored-by: Ben Kunkle <ben@zed.dev>

Follow-up https://github.com/zed-industries/zed/pull/51090

Adds workspace error notifications for project panel drag-and-drop moves
that fail on rename conflicts.

Release Notes:

- N/A

Release Notes:

- Fixed code block scrollbars flashing on vertical scroll


before:

When there are many code blocks, scrolling through markdown will display
a horizontal scrollbar (when the mouse is not inside a code block).


https://github.com/user-attachments/assets/1fae36ec-5a3f-4283-b54f-e5cb4f45646b




after:

When scrolling markdown, do not display the horizontal scrollbar when
the mouse is not in a code block.


https://github.com/user-attachments/assets/0c0f2016-9b18-4055-87a6-4f508dbfd193

---------

Signed-off-by: Xiaobo Liu <cppcoffee@gmail.com>

These are edge cases, but there are a few ways you can get into a state
where you are setting favorites for registry agents and we don't have
the setting yet. This prioritizes `type: registry` for agents that we
have in the registry, especially the previous built-ins.

Release Notes:

- N/A

Closes #46661

This PR changes `fs.rename` to use the platform’s atomic no-overwrite
rename on all platforms when `overwrite` is `false`. This fixes a case
where concurrent renames to the same target could race past a separate
metadata check and end up overwriting each other.

In Project Panel, we can still rename entries in parallel without
worrying about OS internals not handling it correctly or making these
renames sequential.

Release Notes:

- Fixed an issue in the Project Panel where conflicting file moves could
overwrite each other instead of leaving the losing file in place.

This PR takes a different approach to permissions for
assign-reviewers.yml and better filters external PRs for now.

Before you mark this PR as ready for review, make sure that you have:
- ~~[ ] Added a solid test coverage and/or screenshots from doing manual
testing~~
- [x] Done a self-review taking into account security and performance
aspects
- ~~[ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)~~

Release Notes:

- N/A *or* Added/Fixed/Improved ...

Release Notes:

- Fixed ability to select audio input/output devices for legacy
(non-experimental/rodio-enabled) audio.

Add custom `Deserialize` implementations for `AgentType` and
`ExternalAgent` to map old built-in variant names to current custom
agent names, while still accepting current serialized formats.

Release Notes:

- N/A

This pull request adds a new GitHub Actions workflow to automate
reviewer assignment for pull requests. The workflow leverages the
`codeowner-coordinator` repository to intelligently assign the most
relevant teams as reviewers based on the changes in the PR. This should
streamline the review process and ensure the right teams are notified.

**Automated Reviewer Assignment Workflow:**

* Introduced `.github/workflows/assign-reviewers.yml`, a workflow that
triggers on PR open and ready-for-review events to assign 1-2 relevant
teams as reviewers using a script from the
`zed-industries/codeowner-coordinator` repository.
* The workflow checks out the coordinator repo, sets up Python, installs
dependencies, and runs the assignment script with the necessary
environment variables.
* Reviewer assignment is only performed for PRs originating from within
the organization for now.
* The output of the reviewer assignment step is maintained as an Actions
artifact for later inspection or debugging.

Closes #ISSUE

Before you mark this PR as ready for review, make sure that you have:
- [ ] ~~Added a solid test coverage and/or screenshots from doing manual
testing~~
- [x] Done a self-review taking into account security and performance
aspects
- [ ] ~~Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)~~

Release Notes:

- N/A

The "Expand All Files"/"Collapse All Files" button in `BufferSearchBar`
was broken for `SplittableEditor`, which is used in the project diff
view. It was happening because `ProjectDiff::as_searchable` returns an
handle to the `SplittableEditor`, which the search bar implementation
then tries to downcast to an `Editor`, which the `SplittableEditor` did
not support, so both the expand/collapse all buttons, as well as the
collapse state were broken.

Unfortunately this was accidentally introduced in
https://github.com/zed-industries/zed/pull/48773 , so this Pull Request
updates the `Item` implementation for `SplittableEditor` in order for it
to be able to act as an `Editor`.

Release Notes:

- Fix the "Expand All Files"/"Collapse All Files" button in the project
diff view

---------

Co-authored-by: Tom Houlé <tom@tomhoule.com>

Fixes #50835

### Problem :
The "View AI Settings" button on the Welcome page was always rendered
regardless of the disable_ai setting. This made it visible (and
non-functional) for users who had AI disabled, which was confusing.

### Fix :
- Adds an optional visibility: Option<fn(&App) -> bool> predicate field
to SectionEntry
- At render time, Section::render uses filter_map to skip entries whose
predicate returns false.
- The "View AI Settings" entry is given a predicate that checks
!DisableAiSettings::get_global(cx).disable_ai, matching the same pattern
used in `title_bar.rs` and `quick_action_bar.rs`.
- All other entries have visibility: None, meaning they are always shown
— no behaviour change for them.

### Video :
[Screencast from 2026-03-06
20-18-43.webm](https://github.com/user-attachments/assets/cbfab423-3ef3-41dd-a9ab-cbae055eef6e)


Release Notes:

- Fixed the "View AI Settings" button being visible on the Welcome page
despite AI features being disabled in settings.

Before you mark this PR as ready for review, make sure that you have:
- [x] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- N/A

Release Notes:

- N/A *or* Added/Fixed/Improved ...

Fixes a bug that causes the new large agent panel message editor
overrides the ctrl-enter keyboard shortcut to trigger the inline
assistant, rather than sending a message

Release Notes:

- N/A *or* Added/Fixed/Improved ...

Quality-of-life improvement for us Nix users - Zed built via `nix build`
will now correctly the git commit sha in its version

<img width="433" height="298" alt="image"
src="https://github.com/user-attachments/assets/b940ee4a-6914-4410-ba20-b50391282a4e"
/>

Release Notes:

- N/A

Release Notes:

- N/A

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

Just adding this here as an utility component given we were doing
similar things on the sidebar, thread item, and list item. It'd be
probably useful, in the near future, to give this more methods so it's
more flexible.

Release Notes:

- N/A

Closes #50995 

Before you mark this PR as ready for review, make sure that you have:
- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- Fixed extension author's list overflow

<img width="1326" height="369" alt="image"
src="https://github.com/user-attachments/assets/4b2cf9cb-d3c3-4d71-a4fd-9436fb7b1469"
/>

---------

Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

Previously we didn't distinguish between an empty `.related_files[]` and
a case where context collection hadn't run yet. As a result, context
retrieval was always attempted for examples with empty `related_files`.

Release Notes:

- N/A

This PR adjusts the "View More" button in the sidebar to expose threads
in batches of 5. Once you've expanded the whole available set, a button
to collapse the list back to the default number appears at the bottom.
Similarly, as soon as you expand the list even once, a button in the
group header shows up that does the same thing.

No release notes because this is still under feature flag.

Release Notes:

- N/A

Release Notes:

- N/A

Related to AI-79.

Release Notes:

- N/A

Closes #ISSUE

Before you mark this PR as ready for review, make sure that you have:
- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [ ] Done a self-review taking into account security and performance
aspects
- [ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- N/A *or* Added/Fixed/Improved ...

Touching up the scenario in which the project header label is too big.
This uses the same gradient overlay treatment we're using for the thread
item component.

Release Notes:

- N/A

Extract data table modules into separate files

This PR extracts the `tests` and `table_row` modules from
`data_table.rs` into separate files to improve code organization. This
is preparatory work for the upcoming column width API rework (#2 in the
series), where separating mechanical changes from logical changes will
make the review easier.

The extraction was performed using rust-analyzer's "Extract module to
file" command.

**Context:**

This is part 1 of a 3-PR series improving data table column width
handling:
1. **This PR**: Extract modules into separate files (mechanical change)
2. [#51060](https://github.com/zed-industries/zed/pull/51060) -
Introduce width config enum for redistributable column widths (API
rework)
3. Implement independently resizable column widths (new feature)

The series builds on previously merged infrastructure:
- [#46341](https://github.com/zed-industries/zed/pull/46341) - Data
table dynamic column support
- [#46190](https://github.com/zed-industries/zed/pull/46190) - Variable
row height mode for data tables

Primary beneficiary: CSV preview feature
([#48207](https://github.com/zed-industries/zed/pull/48207))

Release Notes:

- N/A

This will help with test times (in some cases), as nextest cannot figure
out whether a given rdep is actually an alive edge of the build graph

Closes #ISSUE

Before you mark this PR as ready for review, make sure that you have:
- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [ ] Done a self-review taking into account security and performance
aspects
- [ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- N/A

This PR adds an action and keybinding to trigger the worktree dropdown
in the agent panel. This is still under a feature flag, so no release
notes yet.

Release Notes:

- N/A