Merge pull request #4619 from inspec/zenspider/empty-tarball

Fix TarProvider when the tarball has empty files in it.

lib/inspec/file_provider.rb

@@ -171,7 +171,7 @@ module Inspec
           path = Pathname.new(name).relative_path_from(here).to_s
 
           @contents[path] = begin # not ||= in a tarball, last one wins
-                              res = entry.read
+                              res = entry.read || ""
                               try = res.dup
                               try.force_encoding Encoding::UTF_8
                               res = try if try.valid_encoding?

test/unit/file_provider_test.rb

@@ -185,6 +185,12 @@ describe Inspec::TarProvider do
     it "must read the contents of the file" do
       _(subject.read("inspec.yml")).must_match(/^name: complete$/)
     end
+
+    it "deals with empty files in tarballs correctly" do
+      path = "test/fixtures/contains-empty-file-0.1.0.tar.gz"
+      f = Inspec::FileProvider.for_path(path)
+      _(f.files.grep(/empty/)).wont_be_empty
+    end
   end
 
   Entry = Struct.new(:full_name) do