fix(undo): Don't create separate commands, since they bubble separately

internal_packages/composer/keymaps/composer.json

@@ -4,8 +4,6 @@
   "composer:show-and-focus-bcc": "mod+shift+b",
   "composer:show-and-focus-from": "mod+shift+f",
   "composer:send-message": "mod+enter",
-  "composer:undo": "mod+z",
-  "composer:redo": "mod+y",
   "composer:no-op": "delete",
   "composer:delete-empty-draft": "escape"
 }

internal_packages/composer/lib/composer-view.jsx

@@ -108,8 +108,8 @@ export default class ComposerView extends React.Component {
       'composer:show-and-focus-cc': () => this.refs.header.showAndFocusField(Fields.Cc),
       'composer:focus-to': () => this.refs.header.showAndFocusField(Fields.To),
       "composer:show-and-focus-from": () => {}, // todo
-      "composer:undo": this.undo,
-      "composer:redo": this.redo,
+      "core:undo": this.undo,
+      "core:redo": this.redo,
     };
   }
 

keymaps/base.json

@@ -1,6 +1,6 @@
 {
   "core:undo": "mod+z",
-  "core:redo": "mod+y",
+  "core:redo": ["mod+shift+z", "mod+y"],
   "core:cut": "mod+x",
   "core:copy": "mod+c",
   "core:paste": "mod+v",