logiguard fork: GPUI xdg-activation keyboard-focus serial fix

Single-commit orphan branch: full zed-industries/zed @ 8c74db0 source tree
with a 3-file patch applied (no upstream history).

Patch (crates/gpui_linux/src/linux/wayland/):
  - serial.rs: add SerialKind::KeyboardEnter
  - client.rs: store wl_keyboard.enter serial; add latest_serial_of()
  - window.rs: activate() uses keyboard-enter serial (Mutter focus gate)

Mutter honors window activation only when the token carries the keyboard-
focus serial from wl_keyboard.enter; GPUI used a stale mouse-press serial.
See docs/tray-window-focus-wayland.md in logiguard.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/fs/tests/integration/fake_git_repo.rs

@@ -0,0 +1,196 @@
+use fs::{FakeFs, Fs};
+use gpui::{BackgroundExecutor, TestAppContext};
+use serde_json::json;
+use std::path::{Path, PathBuf};
+use util::path;
+
+#[gpui::test]
+async fn test_fake_worktree_lifecycle(cx: &mut TestAppContext) {
+    let fs = FakeFs::new(cx.executor());
+    fs.insert_tree("/project", json!({".git": {}, "file.txt": "content"}))
+        .await;
+    let repo = fs
+        .open_repo(Path::new("/project/.git"), None)
+        .expect("should open fake repo");
+
+    // Initially only the main worktree exists
+    let worktrees = repo.worktrees().await.unwrap();
+    assert_eq!(worktrees.len(), 1);
+    assert_eq!(worktrees[0].path, PathBuf::from("/project"));
+
+    fs.create_dir("/my-worktrees".as_ref()).await.unwrap();
+    let worktrees_dir = Path::new("/my-worktrees");
+
+    // Create a worktree
+    let worktree_1_dir = worktrees_dir.join("feature-branch");
+    repo.create_worktree(
+        git::repository::CreateWorktreeTarget::NewBranch {
+            branch_name: "feature-branch".to_string(),
+            base_sha: Some("abc123".to_string()),
+        },
+        worktree_1_dir.clone(),
+    )
+    .await
+    .unwrap();
+
+    // List worktrees — should have main + one created
+    let worktrees = repo.worktrees().await.unwrap();
+    assert_eq!(worktrees.len(), 2);
+    assert_eq!(worktrees[0].path, PathBuf::from("/project"));
+    assert_eq!(worktrees[1].path, worktree_1_dir);
+    assert_eq!(
+        worktrees[1].ref_name,
+        Some("refs/heads/feature-branch".into())
+    );
+    assert_eq!(worktrees[1].sha.as_ref(), "abc123");
+
+    // Directory should exist in FakeFs after create
+    assert!(fs.is_dir(&worktrees_dir.join("feature-branch")).await);
+
+    // Create a second worktree (without explicit commit)
+    let worktree_2_dir = worktrees_dir.join("bugfix-branch");
+    repo.create_worktree(
+        git::repository::CreateWorktreeTarget::NewBranch {
+            branch_name: "bugfix-branch".to_string(),
+            base_sha: None,
+        },
+        worktree_2_dir.clone(),
+    )
+    .await
+    .unwrap();
+
+    let worktrees = repo.worktrees().await.unwrap();
+    assert_eq!(worktrees.len(), 3);
+    assert!(fs.is_dir(&worktree_2_dir).await);
+
+    // Rename the first worktree
+    repo.rename_worktree(worktree_1_dir, worktrees_dir.join("renamed-branch"))
+        .await
+        .unwrap();
+
+    let worktrees = repo.worktrees().await.unwrap();
+    assert_eq!(worktrees.len(), 3);
+    assert!(
+        worktrees
+            .iter()
+            .any(|w| w.path == worktrees_dir.join("renamed-branch")),
+    );
+    assert!(
+        worktrees
+            .iter()
+            .all(|w| w.path != worktrees_dir.join("feature-branch")),
+    );
+
+    // Directory should be moved in FakeFs after rename
+    assert!(!fs.is_dir(&worktrees_dir.join("feature-branch")).await);
+    assert!(fs.is_dir(&worktrees_dir.join("renamed-branch")).await);
+
+    // Rename a nonexistent worktree should fail
+    let result = repo
+        .rename_worktree(PathBuf::from("/nonexistent"), PathBuf::from("/somewhere"))
+        .await;
+    assert!(result.is_err());
+
+    // Remove a worktree
+    repo.remove_worktree(worktrees_dir.join("renamed-branch"), false)
+        .await
+        .unwrap();
+
+    let worktrees = repo.worktrees().await.unwrap();
+    assert_eq!(worktrees.len(), 2);
+    assert_eq!(worktrees[0].path, PathBuf::from("/project"));
+    assert_eq!(worktrees[1].path, worktree_2_dir);
+
+    // Directory should be removed from FakeFs after remove
+    assert!(!fs.is_dir(&worktrees_dir.join("renamed-branch")).await);
+
+    // Remove a nonexistent worktree should fail
+    let result = repo
+        .remove_worktree(PathBuf::from("/nonexistent"), false)
+        .await;
+    assert!(result.is_err());
+
+    // Remove the last worktree
+    repo.remove_worktree(worktree_2_dir.clone(), false)
+        .await
+        .unwrap();
+
+    let worktrees = repo.worktrees().await.unwrap();
+    assert_eq!(worktrees.len(), 1);
+    assert_eq!(worktrees[0].path, PathBuf::from("/project"));
+    assert!(!fs.is_dir(&worktree_2_dir).await);
+}
+
+#[gpui::test]
+async fn test_checkpoints(executor: BackgroundExecutor) {
+    let fs = FakeFs::new(executor);
+    fs.insert_tree(
+        path!("/"),
+        json!({
+            "bar": {
+                "baz": "qux"
+            },
+            "foo": {
+                ".git": {},
+                "a": "lorem",
+                "b": "ipsum",
+            },
+        }),
+    )
+    .await;
+    fs.with_git_state(Path::new("/foo/.git"), true, |_git| {})
+        .unwrap();
+    let repository = fs
+        .open_repo(Path::new("/foo/.git"), Some("git".as_ref()))
+        .unwrap();
+
+    let checkpoint_1 = repository.checkpoint().await.unwrap();
+    fs.write(Path::new("/foo/b"), b"IPSUM").await.unwrap();
+    fs.write(Path::new("/foo/c"), b"dolor").await.unwrap();
+    let checkpoint_2 = repository.checkpoint().await.unwrap();
+    let checkpoint_3 = repository.checkpoint().await.unwrap();
+
+    assert!(
+        repository
+            .compare_checkpoints(checkpoint_2.clone(), checkpoint_3.clone())
+            .await
+            .unwrap()
+    );
+    assert!(
+        !repository
+            .compare_checkpoints(checkpoint_1.clone(), checkpoint_2.clone())
+            .await
+            .unwrap()
+    );
+
+    repository
+        .restore_checkpoint(checkpoint_1.clone())
+        .await
+        .unwrap();
+    assert_eq!(
+        fs.files_with_contents(Path::new("")),
+        [
+            (Path::new(path!("/bar/baz")).into(), b"qux".into()),
+            (Path::new(path!("/foo/a")).into(), b"lorem".into()),
+            (Path::new(path!("/foo/b")).into(), b"ipsum".into())
+        ]
+    );
+
+    // diff_checkpoints: identical checkpoints produce empty diff
+    let diff = repository
+        .diff_checkpoints(checkpoint_2.clone(), checkpoint_3.clone())
+        .await
+        .unwrap();
+    assert!(
+        diff.is_empty(),
+        "identical checkpoints should produce empty diff"
+    );
+
+    // diff_checkpoints: different checkpoints produce non-empty diff
+    let diff = repository
+        .diff_checkpoints(checkpoint_1.clone(), checkpoint_2.clone())
+        .await
+        .unwrap();
+    assert!(diff.contains("b"), "diff should mention changed file 'b'");
+    assert!(diff.contains("c"), "diff should mention added file 'c'");
+}