.

crates/workspace/src/views/repo_detail/browser.rs

@@ -4,6 +4,7 @@
 
 use gpui::prelude::*;
 use gpui::{AnyElement, Context, Entity, SharedString, WeakEntity, div, px};
+use gpui_component::button::{Button, ButtonVariants};
 use gpui_component::clipboard::Clipboard;
 use gpui_component::list::ListItem;
 use gpui_component::spinner::Spinner;
@@ -196,6 +197,23 @@ impl RepoDetailView {
             placeholder("No README found", cx)
         };
 
+        // Latest commit for the current pane: the selected file, or the README
+        // while nothing is selected. Computed after the body above, which
+        // needs `&mut self`.
+        let commit = self
+            .selected_file
+            .as_ref()
+            .and_then(|path| self.commits.get(path.as_ref()))
+            .or_else(|| {
+                if self.selected_file.is_none() {
+                    self.readme_name
+                        .as_ref()
+                        .and_then(|name| self.commits.get(name.as_ref()))
+                } else {
+                    None
+                }
+            });
+
         v_flex()
             .flex_1()
             .min_w_0()
@@ -204,6 +222,7 @@ impl RepoDetailView {
                 h_flex()
                     .px_3()
                     .h_9()
+                    .gap_2()
                     .bg(cx.theme().muted)
                     .border_b(px(1.))
                     .border_color(cx.theme().border)
@@ -215,7 +234,28 @@ impl RepoDetailView {
                             .text_ellipsis()
                             .whitespace_nowrap()
                             .child(pane_title),
-                    ),
+                    )
+                    .when_some(commit, |this, commit| {
+                        this.child(
+                            h_flex()
+                                .flex_1()
+                                .gap_1()
+                                .child(
+                                    Button::new("commit")
+                                        .xsmall()
+                                        .text()
+                                        .label(commit.id.clone()),
+                                )
+                                .child(
+                                    div()
+                                        .max_w(px(250.))
+                                        .text_xs()
+                                        .text_ellipsis()
+                                        .whitespace_nowrap()
+                                        .child(commit.summary.clone()),
+                                ),
+                        )
+                    }),
             )
             .child(div().id("repo-content").flex_1().min_h_0().child(body))
     }

crates/workspace/src/views/repo_detail/mod.rs

@@ -14,6 +14,7 @@ use gpui_component::menu::PopupMenuItem;
 use gpui_component::tree::TreeState;
 use gpui_component::{ActiveTheme, IconName, StyledExt, h_flex, v_flex};
 use signed_core::Announcement;
+use signed_git::FileCommit;
 use signed_state::{GitStore, RepoStore};
 
 mod browser;
@@ -43,6 +44,10 @@ pub struct RepoDetailView {
     files: HashMap<String, FileContent>,
     /// Reads in flight, to avoid duplicate loads.
     loading_files: HashSet<String>,
+    /// Latest commit touching a previewed file (or the README), keyed by path.
+    commits: HashMap<String, FileCommit>,
+    /// Commit queries in flight, to avoid duplicate loads.
+    loading_commits: HashSet<String>,
     /// A clone/fetch is in flight.
     loading: bool,
     error: Option<SharedString>,
@@ -71,6 +76,8 @@ impl RepoDetailView {
             selected_file: None,
             files: HashMap::new(),
             loading_files: HashSet::new(),
+            commits: HashMap::new(),
+            loading_commits: HashSet::new(),
             loading: true,
             error: None,
             focus_handle: cx.focus_handle(),
@@ -113,6 +120,7 @@ impl RepoDetailView {
                         });
                         if let Some((path, bytes)) = readme_path.zip(readme) {
                             this.readme_name = Some(path.to_string_lossy().into());
+                            this.load_commit(&path.to_string_lossy(), cx);
                             if let Ok(text) = String::from_utf8(bytes) {
                                 this.set_markdown(None, &text, cx);
                             }
@@ -165,6 +173,7 @@ impl RepoDetailView {
 
         self.loading_files.insert(path.to_string());
         let path = path.to_string();
+        self.load_commit(&path, cx);
 
         let task = cx.spawn(async move |this, cx| {
             let path_for_read = path.clone();
@@ -222,6 +231,41 @@ impl RepoDetailView {
 
         self.tasks.push(task);
     }
+
+    /// Query the latest commit touching `path` on a background task and cache
+    /// it in [`Self::commits`], for the file header in the content column.
+    fn load_commit(&mut self, path: &str, cx: &mut Context<Self>) {
+        if self.commits.contains_key(path) || self.loading_commits.contains(path) {
+            return;
+        }
+        let Some(worktree) = self.worktree.clone() else {
+            return;
+        };
+
+        self.loading_commits.insert(path.to_string());
+        let path = path.to_string();
+
+        let task = cx.spawn(async move |this, cx| {
+            let path_for_query = path.clone();
+            let result = cx
+                .background_spawn(async move {
+                    signed_git::worktree_last_commit(&worktree, Path::new(&path_for_query))
+                })
+                .await;
+
+            this.update(cx, |this, cx| {
+                this.loading_commits.remove(&path);
+                if let Ok(Some(commit)) = result {
+                    this.commits.insert(path, commit);
+                }
+                cx.notify();
+            })?;
+
+            Ok(())
+        });
+
+        self.tasks.push(task);
+    }
 }
 
 impl Panel for RepoDetailView {

crates/workspace/src/workspace.rs

@@ -21,23 +21,23 @@ pub struct Workspace {
 
 impl Workspace {
     pub fn new(window: &mut Window, cx: &mut Context<Self>) -> Self {
-        let dock =
-            cx.new(|cx| DockArea::new("dock", Some(1), window, cx).panel_style(PanelStyle::TabBar));
+        let style = PanelStyle::TabBar;
+        let dock = cx.new(|cx| DockArea::new("dock", Some(1), window, cx).panel_style(style));
         let weak_dock = dock.downgrade();
+
         let sidebar = cx.new(|cx| SidebarPanel::new(weak_dock.clone(), cx));
+        let weak_sidebar = sidebar.downgrade();
 
         dock.update(cx, |dock_area, cx| {
             dock_area.set_left_dock(
-                DockItem::panel(Arc::new(sidebar.clone())),
-                Some(px(260.)),
+                DockItem::panel(Arc::new(sidebar)),
+                Some(px(240.)),
                 true,
                 window,
                 cx,
             );
         });
 
-        sidebar.update(cx, |sidebar, cx| sidebar.open_explore(window, cx));
-
         let backend = Backend::global(cx);
         let connected = backend.read(cx).is_connected();
         let sync_progress = backend.read(cx).sync_progress();
@@ -86,6 +86,15 @@ impl Workspace {
             passphrase_dialog::open(window, cx);
         }
 
+        // Open the explore panel after the sidebar has been initialized.
+        cx.defer_in(window, move |_, window, cx| {
+            weak_sidebar
+                .update(cx, |this, cx| {
+                    this.open_explore(window, cx);
+                })
+                .ok();
+        });
+
         Self {
             dock,
             status,