feat: default diffs to branch changes

src/editor.rs

@@ -703,6 +703,12 @@ core_actions![
         true
     ),
     ("core.diff", Action::Diff, &[Mode::Normal], true),
+    (
+        "core.diff.mode.toggle",
+        Action::DiffModeToggle,
+        &[Mode::Normal],
+        true,
+    ),
     (
         "core.diff.view.toggle",
         Action::DiffViewToggle,
@@ -1070,6 +1076,7 @@ fn default_bindings() -> HashMap<Mode, HashMap<Input, Binding>> {
     }
     for (key, action) in [
         (Input::Ctrl('o'), JumpBack),
+        (Input::Ctrl('b'), DiffModeToggle),
         (Input::Char('\t'), JumpForward),
         (Input::Alt('h'), PaneFocusLeft),
         (Input::Alt('j'), PaneFocusDown),
@@ -3144,6 +3151,7 @@ impl Editor {
                                     | Action::FilePicker
                                     | Action::FileExplorer
                                     | Action::DiffClose
+                                    | Action::DiffModeToggle
                                     | Action::DiffViewToggle
                                     | Action::DiffOrientationToggle
                                     | Action::WordWrapToggle
@@ -5905,6 +5913,7 @@ impl Editor {
             | Action::BufferForceDelete
             | Action::Diff
             | Action::DiffClose
+            | Action::DiffModeToggle
             | Action::DiffViewToggle
             | Action::DiffOrientationToggle
             | Action::WordWrapToggle
@@ -6713,7 +6722,7 @@ impl Editor {
         }
         if matches!(
             entry.action,
-            Action::DiffViewToggle | Action::DiffOrientationToggle
+            Action::DiffModeToggle | Action::DiffViewToggle | Action::DiffOrientationToggle
         ) {
             let name = entry.ex.expect("diff display action has an Ex command");
             if !args.is_empty() {
@@ -6730,6 +6739,19 @@ impl Editor {
                 self.active.view.command_line.clear();
                 self.active.view.mode = Mode::Normal;
             }
+            if entry.action == Action::DiffModeToggle {
+                let Some(diff) = self.diff.as_mut() else {
+                    self.set_message("No comparison is open");
+                    return None;
+                };
+                if let Err(error) = diff.toggle_comparison_mode() {
+                    self.set_message(error);
+                    return None;
+                }
+                self.release_diff_buffers();
+                self.diff_return_buffer = Some(self.active.id);
+                return None;
+            }
             let Some(diff) = self.diff.as_mut().filter(|diff| diff.phase == Phase::View) else {
                 self.set_message("No comparison is open");
                 return None;