Test for https://github.com/puppetlabs/facter/pull/468.

macadress_spec_nil_elements.diff

diff --git a/spec/unit/macaddress_spec.rb b/spec/unit/macaddress_spec.rb
index 638ef2a..8bc26b1 100755
--- a/spec/unit/macaddress_spec.rb
+++ b/spec/unit/macaddress_spec.rb
@@ -49,6 +49,15 @@ describe "macaddress fact" do
       proc { Facter.value(:macaddress) }.should_not raise_error
       Facter.value(:macaddress).should be_nil
     end
+
+    # when ifconfig isn't installed, nil is returned which should be handled gracefully without any
+    # errors raised
+    it "should not raise any errors when nil is returned" do
+      Facter::Util::IP.stubs(:exec_ifconfig).with(["-a","2>/dev/null"]).
+        returns(nil)
+      proc { Facter.value(:macaddress) }.should_not raise_error
+      Facter.value(:macaddress).should be_nil
+    end
   end
 
   describe "when run on BSD" do

1st attempt at adding tests for puppetlabs/facter#468.
When exec_ifconfig() returns nil (e.g. no ifconfig installed), the modules using its output should not raise any error message.

Unfortunately, this test obviously doesn't work: running facter macaddress shows Could not retrieve macaddress: undefined methodeach_line' for nil:NilClass, but runningrspec spec/unit/util/macaddress_spec.rbshows… 0 failures`.