Aborting navigation throws `undefined`

[diachedelic]

Version

3.1.3

Reproduction link

https://jsfiddle.net/0ukqxgho/1/

Steps to reproduce

Click the /foo button, check the browser console for errors

What is expected?

An Error be thrown.

What is actually happening?

undefined is thrown.

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The docs specify that if a navigation is aborted, then the promise returned by $router.push is rejected. This was causing me grief because I was trying to track down where an Uncaught (in promise) undefined error was being thrown - would have been helpful to have been able to narrow down the error faster.

[posva]

See #3047