worktree: Fix global gitignore on ancestors (#61689)

# Objective

Fixes #61687

Prior to #60772, an `abs_path` outside the `repo_root` would cause a
panic. That PR changed it to return the `abs_path` itself, preventing
the panic, but allowing all parents of `repo_root` to be subject to the
global ignore.

This is not what git itself does.

## Solution

- This change returns `false` when the `abs_path` is outside the
`root_repo`, preventing the panic but also not returning the `abs_path`

## Testing

- One in-memory test
- Manual test by building Zed and confirming the project pane changes
(pictured below)

## 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

## Showcase

### Before, with the bug

<img width="1430" height="814" alt="Screenshot 2026-07-26 at 11 44
11 AM"
src="https://github.com/user-attachments/assets/66e3bb95-4f45-4fd9-a1e4-e7f253f092eb"
/>

### After the fix

<img width="1568" height="1042" alt="Screenshot 2026-07-26 at 12 34
58 PM"
src="https://github.com/user-attachments/assets/588eb01d-830a-4c22-93c0-667742de90b6"
/>

Release Notes:

- Fixed the project panel's global gitignore incorrectly matching parent
directories of a repository

---------

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

crates/worktree/src/ignore.rs

@@ -85,12 +85,14 @@ impl IgnoreStack {
             IgnoreStackEntry::Global { ignore } => {
                 let combined_path;
                 let abs_path = if let Some(repo_root) = self.repo_root.as_ref() {
-                    if let Ok(relative_path) = abs_path.strip_prefix(repo_root) {
-                        combined_path = ignore.path().join(relative_path);
-                        &combined_path
-                    } else {
-                        abs_path
-                    }
+                    let Ok(relative_path) = abs_path.strip_prefix(repo_root) else {
+                        // The provided absolute path is outside of the repository's folderabs_path is outside repo_root and cannot be ignored
+                        // by this global ignore
+                        return false;
+                    };
+
+                    combined_path = ignore.path().join(relative_path);
+                    &combined_path
                 } else {
                     abs_path
                 };

crates/worktree/tests/integration/worktree_tests.rs

@@ -3621,34 +3621,37 @@ async fn test_global_gitignore(executor: BackgroundExecutor, cx: &mut TestAppCon
     init_test(cx);
 
     let home = paths::home_dir();
+    let project_path = home.join("example.com").join("project");
     let fs = FakeFs::new(executor);
     fs.insert_tree(
         home,
         json!({
             ".config": {
                 "git": {
-                    "ignore": "foo\n/bar\nbaz\n"
+                    "ignore": "foo\n/bar\nbaz\n*.com\n"
                 }
             },
-            "project": {
-                ".git": {},
-                ".gitignore": "!baz",
-                "foo": "",
-                "bar": "",
-                "sub": {
-                    "bar": "",
-                },
-                "subrepo": {
+            "example.com": {
+                "project": {
                     ".git": {},
-                    "bar": ""
-                },
-                "baz": ""
+                    ".gitignore": "!baz",
+                    "foo": "",
+                    "bar": "",
+                    "sub": {
+                        "bar": "",
+                    },
+                    "subrepo": {
+                        ".git": {},
+                        "bar": ""
+                    },
+                    "baz": ""
+                }
             }
         }),
     )
     .await;
     let worktree = Worktree::local(
-        home.join("project"),
+        project_path.clone(),
         true,
         fs.clone(),
         Arc::default(),
@@ -3681,7 +3684,7 @@ async fn test_global_gitignore(executor: BackgroundExecutor, cx: &mut TestAppCon
     // Ignore statuses are updated when excludesFile changes
     fs.write(
         &home.join(".config").join("git").join("ignore"),
-        "/bar\nbaz\n".as_bytes(),
+        "/bar\nbaz\n*.com\n".as_bytes(),
     )
     .await
     .unwrap();
@@ -3705,7 +3708,7 @@ async fn test_global_gitignore(executor: BackgroundExecutor, cx: &mut TestAppCon
 
     // Statuses are updated when .git added/removed
     fs.remove_dir(
-        &home.join("project").join("subrepo").join(".git"),
+        &project_path.join("subrepo").join(".git"),
         RemoveOptions {
             recursive: true,
             ..Default::default()