grpc: Fix prototype pollution possibility in loadPackageDefinition

[murgatroid99]

This is a port of #1654 to the old grpc library.

Credit to @d3v53c for the original fix.

[d3v53c]

Hi @murgatroid99 , @nicolasnoble ,

I've tried to improve the fix a little more by using indexOf instead of includes. Please have a look at the implementations.

1. PR-1
2. PR-2

Cheers!

[murgatroid99]

Are the changes in this PR incorrect in some way? Or, in other words, why specifically do you consider the PRs you linked improvements over this one?

[d3v53c]

Are the changes in this PR incorrect in some way? Or, in other words, why specifically do you consider the PRs you linked improvements over this one?

Sorry for the late reply.

The changes are correct when considering the newer versions of JavaScript. The Array.prototype.includes is only introduced in ECMAScript 2016 version.
Since, we're looking at an old library and for the sake of compatibility on older versions, it'd probably be better to fallback to Array.prototype.indexOf implementations. Please feel free to correct me if I'm wrong.

Cheers!!