$slots don't show correct slots when using slot scope

[lindesvard]

Version

2.4.4

Reproduction link

https://jsfiddle.net/036scaat/6/

Steps to reproduce

Create a child component with two slots and .
If you now use the named slot with scope feature the child components $slots variable will only have the default.

What is expected?

Object.keys(this.$slots) === ["default", "xxx"]
Removed scope="props" from template and it gives expected result --> https://jsfiddle.net/036scaat/8/

What is actually happening?

Object.keys(this.$slots) === ["default"]

[yyx990803]

Scoped slots are stored in a different property: https://vuejs.org/v2/api/#vm-scopedSlots