New (2.6 ) slot syntax results in slots not added to vm.$slots, breaking existing render functions

Version

2.6.1

Reproduction link

https://jsfiddle.net/3kpf9u54/4/

Steps to reproduce

1. Observe the contents of the <template> displayed
2. Change the code from <template slot="content"> to <template #content> or <template v-slot:content> and observe the contents stop being displayed
3. Change the render function code from this.$slots.content to this.$scopedSlots.content() and observe the contents be displayed again

What is expected?

Contents are displayed all the time; old render functions don’t break when used with new syntax

What is actually happening?

New syntax forces slots into being scoped, breaking existing render functions

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I’m actually not sure if this is intentional or not, but it breaks Vuetify, and probably other things too. Assuming this is intentional, it makes writing functional components more difficult, as you have to either:

1. check both this.$slots (for Vue pre-2.6) and this.$scopedSlots (for Vue post-2.6)
2. only check this.$scopedSlots and ask Vue pre-2.6 users to add slot-scope everywhere so all slots become scoped
3. only check this.$slots and ask Vue post-2.6 users to use the legacy syntax

[joelpro2]

i made a simple test and v-slot still dont add the slots in $slots fiddle My bad, i was using vue 2.6.0, its corrected in 2.6.10

[yyx990803]

In 0e8560d0 I’ve made it so that only slots using the new v-slot syntax without scope are exposed on this.$slots. This should ensure intended behavior without affecting existing usage of legacy slots.