Fix deduping

Author: ConradIrwin

Cargo.lock

@@ -44,7 +44,6 @@ multi_buffer.workspace = true
 notifications.workspace = true
 panel.workspace = true
 picker.workspace = true
-postage.workspace = true
 project.workspace = true
 schemars.workspace = true
 serde.workspace = true

crates/git_ui/Cargo.toml

@@ -101,9 +101,17 @@ impl ProjectDiff {
         window: &mut Window,
         cx: &mut Context<Workspace>,
     ) {
+        telemetry::event!("Git Branch Diff Opened");
         let project = workspace.project().clone();
+
+        let existing = workspace
+            .items_of_type::<Self>(cx)
+            .find(|item| matches!(item.read(cx).diff_base(cx), DiffBase::Merge { .. }));
+        if let Some(existing) = existing {
+            workspace.activate_item(&existing, true, true, window, cx);
+            return;
+        }
         let workspace = cx.entity();
-        // todo!() only open one at a time
         window
             .spawn(cx, async move |cx| {
                 let this = cx
@@ -135,8 +143,10 @@ impl ProjectDiff {
                 "Action"
             }
         );
-        // todo!() don't de-dupe with the branch diff
-        let project_diff = if let Some(existing) = workspace.item_of_type::<Self>(cx) {
+        let existing = workspace
+            .items_of_type::<Self>(cx)
+            .find(|item| matches!(item.read(cx).diff_base(cx), DiffBase::Head));
+        let project_diff = if let Some(existing) = existing {
             workspace.activate_item(&existing, true, true, window, cx);
             existing
         } else {

crates/git_ui/src/project_diff.rs

@@ -360,9 +360,6 @@ impl BranchDiff {
     }
 }
 
-// HEAD and working tree are the same
-// but merge base and HEAD diff
-// todo!() is this right...?
 fn diff_status_to_file_status(branch_diff: &git::status::TreeDiffStatus) -> FileStatus {
     let file_status = match branch_diff {
         git::status::TreeDiffStatus::Added { .. } => FileStatus::Tracked(TrackedStatus {