fix(renderer): check vnode type is svg tag (#639)

[yyyanghj]

close #639

[yyx990803]

Thanks, but the isSVGTag utility should be used in compiler only (it bloats runtime size). A proper fix is landed in 035b656

[yyyanghj]

Thanks, but the isSVGTag utility should be used in compiler only (it bloats runtime size). A proper fix is landed in 035b656

But this example still doesn't work

const App = {
  template: `
    <div id="App">
      <svg width="200" height="200">
        <circle :class="clazz" cx="100" cy="100" r="80"></circle>
      </svg>
      <div @click="handleClick">click me!</div>
    </div>
  `,
  data: {
    clazz: 'foo'
  },
  methods: {
    handleClick() {
      this.clazz = 'bar'
    }
  }
}

[yyx990803]

Hmm yes, this happens because optimized patch don't start from component root. I think we will need a flag on vnodes for svg to mark svg as block roots during compilation.

[yyx990803]

Should be fixed in f2ac28b

[yyyanghj]

Should be fixed in f2ac28b

I think we should do something with <foreignObject> .

const App = {
  template: `
    <div id="App">
      <svg width="200" height="200">
        <foreignObject>
          <div></div>
        </foreignObject>
      </svg>
    </div>
  `
}

The <foreignObject> includes a <div> and <div> is not a svg element. Now it is marked as a svg element. It may cause some bugs.

[yyx990803]

Good catch! Addressed in 4f06eeb