git: Fix git info exclude action for worktrees (#63967)

# Objective

- This PR fixes #63760. According to git docs "Patterns read from
$GIT_DIR/info/exclude".

## Solution

- We were reading the directory's absolute path instead of reading the
absolute path to the repository's common .git directory.


## Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [ ] 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)
- [ ] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

---

Release Notes:

- Fixed "Add to .git/info/exclude" not working when used from a
secondary git worktree

---------

Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>

crates/project/src/git_store.rs

@@ -8413,7 +8413,7 @@ impl Repository {
         is_dir: bool,
     ) -> oneshot::Receiver<Result<()>> {
         let id = self.id;
-        let repository_dir = self.snapshot.repository_dir_abs_path.clone();
+        let repository_dir = self.snapshot.common_dir_abs_path.clone();
         let path_display = repo_path.as_ref().display(PathStyle::Unix);
         let path = repo_path.as_unix_str().to_owned();
         let file_path_str = if is_dir {

crates/remote_server/src/remote_editing_tests.rs

@@ -3702,6 +3702,92 @@ async fn test_add_path_to_git_info_exclude_in_remote_repository(
     );
 }
 
+#[gpui::test]
+async fn test_add_path_to_git_info_exclude_in_remote_linked_worktree(
+    cx: &mut TestAppContext,
+    server_cx: &mut TestAppContext,
+) {
+    let fs = FakeFs::new(server_cx.executor());
+    fs.insert_tree(
+        "/project",
+        json!({
+            ".git": {
+                "HEAD": "ref: refs/heads/main",
+                "config": "[core]\n\tbare = false\n",
+                "info": {
+                    "exclude": "existing\n",
+                },
+                "worktrees": {
+                    "linked": {
+                        "HEAD": "ref: refs/heads/linked",
+                        "commondir": "../..",
+                        "gitdir": "/worktree/.git",
+                    },
+                },
+            },
+        }),
+    )
+    .await;
+    fs.insert_tree(
+        "/worktree",
+        json!({
+            ".git": "gitdir: ../project/.git/worktrees/linked\n",
+            "logs": {
+                "app.log": "",
+            },
+            "tmp.txt": "",
+        }),
+    )
+    .await;
+    let repository_dir = Path::new("/project/.git/worktrees/linked");
+    fs.set_branch_name(repository_dir, Some("linked"));
+    fs.set_head_for_repo(repository_dir, &[], "head-sha");
+
+    let (project, _headless) = init_test(&fs, cx, server_cx).await;
+    project
+        .update(cx, |project, cx| {
+            project.find_or_create_worktree(Path::new("/worktree"), true, cx)
+        })
+        .await
+        .expect("should open remote linked worktree");
+    cx.run_until_parked();
+
+    let repository = project.read_with(cx, |project, cx| {
+        project
+            .active_repository(cx)
+            .expect("remote linked worktree should have an active repository")
+    });
+
+    for (path, is_dir) in [("tmp.txt", false), ("logs", true), ("tmp.txt", false)] {
+        let repo_path = RepoPath::new(path).expect("path should be a valid repo path");
+        cx.update(|cx| {
+            repository.update(cx, |repository, _| {
+                repository.add_path_to_git_info_exclude(&repo_path, is_dir)
+            })
+        })
+        .await
+        .expect("add to info/exclude request should complete")
+        .expect("add to info/exclude should succeed for remote linked worktree");
+    }
+
+    server_cx.run_until_parked();
+    cx.run_until_parked();
+
+    assert_eq!(
+        fs.load(Path::new("/project/.git/info/exclude"))
+            .await
+            .expect("shared info/exclude should be readable"),
+        "existing\ntmp.txt\nlogs/\n"
+    );
+    assert!(
+        fs.metadata(&repository_dir.join("info/exclude"))
+            .await
+            .expect("worktree-specific info/exclude metadata should be readable")
+            .is_none(),
+        "the action should not create a worktree-specific info/exclude"
+    );
+}
+
 #[gpui::test]
 async fn test_remote_git_diffs(cx: &mut TestAppContext, server_cx: &mut TestAppContext) {
     let text_2 = "