当购物车为空时，全选框不能被选中。

src/main/webapp/resources/view/usercenter/forstore/buyer_cart.html

@@ -505,7 +505,7 @@
 			<!--购物车清单-->
 			<dl style="display: inline-block;" when-scrolled="scrollLoadData()">
 				<dt>
-					<span class="wd01"><input type="checkbox" id="checkonAll" name="checkbox" ng-checked="isChooseAll" ng-click="chooseAllCarts()"/><label for="checkonAll"></label></span>
+					<span class="wd01"><input ng-disabled="cartMap.length == 0" type="checkbox" id="checkonAll" name="checkbox" ng-checked="isChooseAll" ng-click="chooseAllCarts()"/><label for="checkonAll" ng-disabled="cartMap.length == 0"></label></span>
 					<span class="wid24">产品信息</span>
 					<span class="wd02">交期(天)</span>
 					<span>单价</span>