fixes #37229

src/vs/workbench/parts/scm/electron-browser/dirtydiffDecorator.ts

@@ -380,6 +380,10 @@ export class ShowPreviousChangeAction extends EditorAction {
 			return;
 		}
 
+		if (!controller.canNavigate()) {
+			return;
+		}
+
 		controller.previous();
 	}
 }
@@ -410,6 +414,10 @@ export class ShowNextChangeAction extends EditorAction {
 			return;
 		}
 
+		if (!controller.canNavigate()) {
+			return;
+		}
+
 		controller.next();
 	}
 }
@@ -477,6 +485,10 @@ export class DirtyDiffController implements IEditorContribution {
 		return DirtyDiffController.ID;
 	}
 
+	canNavigate(): boolean {
+		return this.currentIndex === -1 || this.model.changes.length > 1;
+	}
+
 	next(lineNumber?: number): void {
 		if (!this.assertWidget()) {
 			return;