client/systray: add menu item to rebuild the menu

This shouldn't be necessary, but while we're continuing to figure out
the root cause, this is better than having to restart the app or switch
profiles on the command line.

Updates #15528

Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d
Signed-off-by: Will Norris <will@tailscale.com>

client/systray/systray.go

@@ -84,12 +84,13 @@ type Menu struct {
 	bgCancel context.CancelFunc
 
 	// Top-level menu items
-	connect    *systray.MenuItem
-	disconnect *systray.MenuItem
-	self       *systray.MenuItem
-	exitNodes  *systray.MenuItem
-	more       *systray.MenuItem
-	quit       *systray.MenuItem
+	connect     *systray.MenuItem
+	disconnect  *systray.MenuItem
+	self        *systray.MenuItem
+	exitNodes   *systray.MenuItem
+	more        *systray.MenuItem
+	rebuildMenu *systray.MenuItem
+	quit        *systray.MenuItem
 
 	rebuildCh  chan struct{} // triggers a menu rebuild
 	accountsCh chan ipn.ProfileID
@@ -295,6 +296,17 @@ func (menu *Menu) rebuild() {
 		})
 	}
 
+	// TODO(#15528): this menu item shouldn't be necessary at all,
+	// but is at least more discoverable than having users switch profiles or exit nodes.
+	menu.rebuildMenu = systray.AddMenuItem("Rebuild menu", "Fix missing menu items")
+	onClick(ctx, menu.rebuildMenu, func(ctx context.Context) {
+		select {
+		case <-ctx.Done():
+		case menu.rebuildCh <- struct{}{}:
+		}
+	})
+	menu.rebuildMenu.Enable()
+
 	menu.quit = systray.AddMenuItem("Quit", "Quit the app")
 	menu.quit.Enable()