fix `pull-request` from branch tracking another local branch

In this case, pretend there is no upstream configuration at all.

Closes #141

lib/hub/commands.rb

@@ -108,7 +108,11 @@ module Hub
       options[:base] ||= master_branch.short_name
 
       if tracked_branch = options[:head].nil? && current_branch.upstream
-        if base_project == head_project and tracked_branch.short_name == options[:base]
+        if !tracked_branch.remote?
+          # The current branch is tracking another local branch. Pretend there is
+          # no upstream configuration at all.
+          tracked_branch = nil
+        elsif base_project == head_project and tracked_branch.short_name == options[:base]
           $stderr.puts "Aborted: head branch is the same as base (#{options[:base].inspect})"
           warn "(use `-h <branch>` to specify an explicit pull request head)"
           abort

lib/hub/context.rb

@@ -130,7 +130,7 @@ module Hub
       end
 
       def upstream_project
-        if branch = current_branch and upstream = branch.upstream
+        if branch = current_branch and upstream = branch.upstream and upstream.remote?
           remote = remote_by_name upstream.remote_name
           remote.project
         end

test/hub_test.rb

@@ -839,7 +839,6 @@ class HubTest < Test::Unit::TestCase
   def test_pullrequest_from_tracking_branch
     stub_branch('refs/heads/feature')
     stub_tracking('feature', 'mislav', 'yay-feature')
-    stub_command_output "rev-list --cherry-pick --right-only --no-merges mislav/master...", nil
 
     stub_request(:post, "https://#{auth}github.com/api/v2/json/pulls/defunkt/hub").
       with(:body => { 'pull' => {'base' => "master", 'head' => "mislav:yay-feature", 'title' => "hereyougo"} }).
@@ -849,6 +848,18 @@ class HubTest < Test::Unit::TestCase
     assert_output expected, "pull-request hereyougo -f"
   end
 
+  def test_pullrequest_from_branch_tracking_local
+    stub_branch('refs/heads/feature')
+    stub_tracking('feature', 'refs/heads/master')
+
+    stub_request(:post, "https://#{auth}github.com/api/v2/json/pulls/defunkt/hub").
+      with(:body => { 'pull' => {'base' => "master", 'head' => "tpw:feature", 'title' => "hereyougo"} }).
+      to_return(:body => mock_pullreq_response(1))
+
+    expected = "https://github.com/defunkt/hub/pull/1\n"
+    assert_output expected, "pull-request hereyougo -f"
+  end
+
   def test_pullrequest_enterprise_no_tracking
     stub_hub_host('git.my.org')
     stub_repo_url('git@git.my.org:defunkt/hub.git')
@@ -1287,13 +1298,13 @@ config
       stub_command_output 'symbolic-ref -q HEAD', value
     end
 
-    def stub_tracking(from, remote_name, remote_branch)
+    def stub_tracking(from, upstream, remote_branch = nil)
       stub_command_output "rev-parse --symbolic-full-name #{from}@{upstream}",
-        remote_branch ? "refs/remotes/#{remote_name}/#{remote_branch}" : nil
+        remote_branch ? "refs/remotes/#{upstream}/#{remote_branch}" : upstream
     end
 
     def stub_tracking_nothing(from = 'master')
-      stub_tracking(from, nil, nil)
+      stub_tracking(from, nil)
     end
 
     def stub_remotes_group(name, value)