core: Fix Downloader tests

lib/vagrant/util/downloader.rb

@@ -40,6 +40,7 @@ module Vagrant
       def download!
         options, subprocess_options = self.options
         options += ["--output", @destination]
+        options << @source
 
         # This variable can contain the proc that'll be sent to
         # the subprocess execute.
@@ -122,6 +123,7 @@ module Vagrant
       def head
         options, subprocess_options = self.options
         options.unshift("-I")
+        options << @source
 
         @logger.info("HEAD: #{@source}")
         result = execute_curl(options, subprocess_options)
@@ -177,7 +179,6 @@ module Vagrant
         options += ["--continue-at", "-"] if @continue
         options << "--insecure" if @insecure
         options << "--cert" << @client_cert if @client_cert
-        options << @source
 
         # Specify some options for the subprocess
         subprocess_options = {}

test/unit/vagrant/util/downloader_test.rb

@@ -54,4 +54,22 @@ describe Vagrant::Util::Downloader do
       pending "tests for a UI"
     end
   end
+
+  describe "#head" do
+    let(:curl_options) {
+      ["--fail", "--location", "--max-redirs", "10", "--user-agent", described_class::USER_AGENT, source, {}]
+    }
+
+    it "returns the output" do
+      subprocess_result.stub(stdout: "foo")
+
+      options = curl_options.dup
+      options.unshift("-I")
+
+      Vagrant::Util::Subprocess.should_receive(:execute).
+        with("curl", *options).and_return(subprocess_result)
+
+      expect(subject.head).to eq("foo")
+    end
+  end
 end