更改canvas元素的宽度或高度后，其2d上下文的字体设置为默认值

Question

var cvs = Damoo.dom.createElement('canvas'),
    ctx = cvs.getContext('2d');
ctx.font = f.value;
cvs.width = ctx.measureText("text").width;
cvs.height = f.size * 1.2;
//now the font value set to default value, you must reset it
ctx.font = f.value;

所以任何人都知道这是一个错误还是设计？ 环境是最新的Chrome

当我尝试保存和恢复时，代码是

var cvs = Damoo.dom.createElement('canvas'),
    ctx = cvs.getContext('2d');
ctx.font = f.value;
cvs.save();
cvs.width = ctx.measureText("text").width;
cvs.height = f.size * 1.2;
//now the font value set to default value, you must reset it
//ctx.font = f.value;
cvs.restore();