TypeError in Tooltip when the slot content isn't an element

[KuroThing]

The error as per chrome: TypeError: Cannot read property 'addEventListener' of undefined
The error as per firefox: TypeError: e._trigger is undefined

A jsfiddle that reproduces the error, just check your browsers console after running the example.

From what i can gather, it appears the problem stems from the fact that this._trigger assumes that the child is a html element, and it continues until addListener is called, which will then throw an error.

If this is the intended behaviour, could this please be documented somewhere on at least Tooltip, and also Popover if it is also impacted by this along with a sanity check to see if the child is a html element and a custom error being thrown with an improved error message that clearly indicates the problem.

[pi0]

@KuroThing In next release it is possible without wrapping inside <span> :
<b-tooltip content="Foo">Bar Baz</b-tooltip>