v-slot not used seems to exist

[tcastelly]

Version

2.6.3

Reproduction link

https://jsfiddle.net/shenron/xmykud6z/29/

Steps to reproduce

I have component and sub component. I want to pass slot from the parent to a child.
In this example I have v-modal-confirm and v-modal both can display a title thanks to a prop or with slot.

In the line 2 of my html demo, I use a title prop without slot. This slot seems to be created anyway, because the default behavior to print the title in v-modal is not called.

What is expected?

The default print of the slot in the v-modal should be visible

What is actually happening?

Nothing is printed

---

It works with the deprecated syntax.

[tcastelly]

I use this workaround: https://jsfiddle.net/shenron/xmykud6z/35/

Test the $sclopedSlots before display the slot.

[pmochine]

@tcastelly I think I had a similar issue, here is my example: https://jsfiddle.net/56e2jr79/1/

If you try the new syntax on the

//old syntax
<slot
  name="reference"
  slot="reference"
/>

with 

//new syntax
<template #reference>
 <slot
    name="reference"
  />
</template>

It wouldn't show it up...

So the last commit should fix it up? @yyx990803 (thx)

[yyx990803]

@pmochine yes, I believe so.