(PUP-11717) Protect against facter returning a Hash subclass

Facter.resolve v4 returns a Facter::FactCollection Hash subclass unlilke Facter
v3. This causes functions like `dig` to fail, since the function only
accepts a Collection type, not a Runtime type:

    dig($facts, "ruby", "version")

Protect against this by calling `to_h`. If the object is a Hash, it will return
`self`. If the object is derived from Hash, it will return a new Hash containing
the contents of the object.

Author: joshcooper

lib/puppet/indirector/facts/facter.rb

@@ -40,7 +40,10 @@ def find(request)
                Puppet::Node::Facts.new(request.key, Puppet.runtime[:facter].to_hash)
              else
                # resolve does not return legacy facts unless requested
-               Puppet::Node::Facts.new(request.key, Puppet.runtime[:facter].resolve(''))
+               facts = Puppet.runtime[:facter].resolve('')
+               # some versions of Facter 4 return a Facter::FactCollection instead of
+               # a Hash, breaking API compatibility, so force a hash using `to_h`
+               Puppet::Node::Facts.new(request.key, facts.to_h)
              end
 
     result.add_local_facts unless request.options[:resolve_options]

spec/unit/indirector/facts/facter_spec.rb

@@ -1,6 +1,8 @@
 require 'spec_helper'
 require 'puppet/indirector/facts/facter'
 
+class Puppet::Node::Facts::Facter::MyCollection < Hash; end
+
 describe Puppet::Node::Facts::Facter do
   FS = Puppet::FileSystem
 
@@ -87,11 +89,24 @@
     it "can exclude legacy facts" do
       Puppet[:include_legacy_facts] = false
 
-      facts = Puppet::Node::Facts.new("foo")
-      expect(Puppet::Node::Facts).to receive(:new).and_return(facts)
       expect(Puppet.runtime[:facter]).to receive(:resolve).with('')
+        .and_return({'kernelversion' => '1.2.3'})
 
-      @facter.find(@request)
+      values = @facter.find(@request).values
+      expect(values).to be_an_instance_of(Hash)
+      expect(values).to include({'kernelversion' => '1.2.3'})
+    end
+
+    it "can exclude legacy facts using buggy facter implementations that return a Hash subclass" do
+      Puppet[:include_legacy_facts] = false
+
+      collection = Puppet::Node::Facts::Facter::MyCollection["kernelversion" => '1.2.3']
+      expect(Puppet.runtime[:facter]).to receive(:resolve).with('')
+        .and_return(collection)
+
+      values = @facter.find(@request).values
+      expect(values).to be_an_instance_of(Hash)
+      expect(values).to include({'kernelversion' => '1.2.3'})
     end
   end