<b-table> empty scoped slot renders unwanted default value

[Hiws]

Describe the bug

If you have a scoped slot with conditional content, for example only showing something if an array has elements.
If the slot is completely empty it will render out the default value, which in this case would be [] which might not be wanted.

Steps to reproduce the bug

1. Create a table with a scoped slot.
2. Leave the slot empty or add a v-if
3. If the v-if is not met and the slot is empty it will display the default content.

Expected behavior

If the v-if is not be and the scoped slot is empty, it should not render anything.

Versions

Libraries:

• BootstrapVue: 2.0.0-rc.28
• Bootstrap: 4.3.1
• Vue: 2.x.x

Demo link

https://codepen.io/Hiws/pen/jONrbGX

[tmorehouse]

Workaround: use a v-else to render a  

Fix will be available in 2.0.0 stable.

Note that the data cell scoped slot names will be changing in 2.0.0 stable, due to issues and limitations with Vue's new v-slot syntax. vuejs/rfcs#2 (comment)

[tmorehouse]

BootstrapVue v2.0.0 stable has been released. See https://bootstrap-vue.js.org/docs/misc/changelog