Version
2.4.1

Reproduction link
https://jsfiddle.net/razvansbsb/a7qpurfs/

Steps to reproduce

1. Define a component A that uses 2 mixins that each define their own provide properties, e.g. foo and bar.
2. Define a component B inside A that uses inject to add foo and bar properties

What is expected?
Both foo and bar should be available in component B.

What is actually happening?
parentVal.call is not a function exception is being thrown