Fix issue where the following causes obscure catalog compilation errors:
authorAlex Dacre <alex.dacre@cirrus.com>
Wed, 26 Apr 2017 11:47:29 +0000 (12:47 +0100)
committerHelen Campbell <helen@puppetlabs.com>
Tue, 9 May 2017 12:16:08 +0000 (13:16 +0100)
commit5ad49ebaecbdbc6faa58282c45aad1c46d4d7f2c
tree1788020ff56acfaa72c978df184f31c60ccc1805
parent419ffeb1d167a05af6858e2e4749f6414532f5d2
Fix issue where the following causes obscure catalog compilation errors:

```
file { '/tmp/somefile':
  ensure => 'file',
}

File['/tmp/somefile'] -> Package <| |>

ensure_packages($somearray)
```

If $somearray is undefined or one of the elements contains an empty
string, an error like the following is thrown:

Could not find resource 'Package[]' for relationship from
'File[/tmp/somefile]' on node $::fqdn
lib/puppet/parser/functions/ensure_packages.rb