<slot> will lost the first scoped style when the tags has a selector with v-if

[HuberTRoy]

Version

2.6.10

Reproduction link

https://codesandbox.io/s/vue-template-ptrum?fontsize=14

Steps to reproduce

When the parent style is scoped the <slot> will lost the style of the first tag if other tags on component has a selector with v-if.

Example:

Main.vue:

<template>
  <Test>
    <div class="test">
      <div class="test2">
      </div>
      <div class="test2">
      </div>
    </div>
  </Test>
</template>
<script>
import Test from './Test.vue'
export default {
     components: {
        Test
    }
}
</script>
<style scoped>
.test {
    display: flex;
}

.test2 {
   width: 200px;
   height: 200px;
   background: black;
}
</style>

Test.vue

<template>
  <div>
    <div v-if="f" class="_test_style_class_name">
    </div>
    <slot v-else>
    </slot>
  </div>
</template>
<script>
export default {
     data () {
         return {
             f: true
         }     
     },
     mounted () {  this.f = false }
}
</script>

Open it on Chrome, and no style set on class test but I have set it on Main.vue.
If I remove class="..." or remove v-if="f" on Test.vue then the class test will set..

Is it that I lost something to know in using <slot>?

Thanks.

What is expected?

No lost style.

What is actually happening?

No Style set on the first tag.

[Justineo]

Duplicate of #10416