Fix unintended hiding of inline actions on SCM Changes view (fix microsoft#272716) (microsoft#272717)

Author: gjsjohnmurray

src/vs/workbench/contrib/scm/browser/menus.ts

@@ -348,10 +348,11 @@ export class SCMMenus implements ISCMMenus, IDisposable {
 				// In order to keep the Repositories view clean, we hide the
 				// primary actions by default. Users can always promote actions
 				// from the `...` menu to inline actions.
+				let itemToAppend = menuItem;
 				if (isIMenuItem(menuItem) && menuItem.group === 'navigation') {
-					menuItem.isHiddenByDefault = true;
+					itemToAppend = { ...menuItem, isHiddenByDefault: true };
 				}
-				this.repositoryMenuDisposables.add(MenuRegistry.appendMenuItem(MenuId.SCMSourceControlInline, menuItem));
+				this.repositoryMenuDisposables.add(MenuRegistry.appendMenuItem(MenuId.SCMSourceControlInline, itemToAppend));
 			}
 		}));
 	}