github.rb in danger-0.8.3

- old
+ new

@@ -36,19 +36,19 @@
         @markdown_parser ||= Redcarpet::Markdown.new(Redcarpet::Render::HTML, no_intra_emphasis: true)
       end
 
       def setup_danger_branches
         # we can use a github specific feature here:
-        pull_id = self.ci_source.pull_request_id
-        test_branch = self.pr_json[:base][:sha]
+        base_commit = self.pr_json[:base][:sha]
+        head_commit = self.scm.head_commit
 
         # Next, we want to ensure that we have a version of the current branch at a known location
-        self.scm.exec "branch #{EnvironmentManager.danger_base_branch} #{test_branch}"
+        self.scm.exec "branch #{EnvironmentManager.danger_base_branch} #{base_commit}"
 
         # OK, so we want to ensure that we have a known head branch, this will always represent
         # the head of the PR ( e.g. the most recent commit that will be merged. )
-        self.scm.exec "fetch origin +refs/pull/#{pull_id}/merge:#{EnvironmentManager.danger_head_branch}"
+        self.scm.exec "branch #{EnvironmentManager.danger_head_branch} #{head_commit}"
       end
 
       def fetch_details
         self.pr_json = client.pull_request(ci_source.repo_slug, ci_source.pull_request_id)
         fetch_issue_details(self.pr_json)
@@ -104,26 +104,35 @@
         submit_pull_request_status!(warnings: warnings,
                                       errors: errors,
                                  details_url: comment_result['html_url'])
       end
 
-      def submit_pull_request_status!(warnings: nil, errors: nil, details_url: nil)
+      def submit_pull_request_status!(warnings: [], errors: [], details_url: [])
         status = (errors.count == 0 ? 'success' : 'failure')
         message = generate_github_description(warnings: warnings, errors: errors)
-        client.create_status(ci_source.repo_slug, latest_pr_commit_ref, status, {
-          description: message,
-          context: "danger/danger",
-          target_url: details_url
-        })
-      rescue
-        # This usually means the user has no commit access to this repo
-        # That's always the case for open source projects where you can only
-        # use a read-only GitHub account
-        if errors.count > 0
-          # We need to fail the actual build here
-          abort("\nDanger has failed this build. \nFound #{'error'.danger_pluralize(errors.count)} and I don't have write access to the PR set a PR status.")
-        else
-          puts message
+
+        latest_pr_commit_ref = self.pr_json[:head][:sha]
+
+        if latest_pr_commit_ref.empty? || latest_pr_commit_ref.nil?
+          raise "Couldn't find a commit to update its status".red
+        end
+
+        begin
+          client.create_status(ci_source.repo_slug, latest_pr_commit_ref, status, {
+            description: message,
+            context: "danger/danger",
+            target_url: details_url
+          })
+        rescue
+          # This usually means the user has no commit access to this repo
+          # That's always the case for open source projects where you can only
+          # use a read-only GitHub account
+          if errors.count > 0
+            # We need to fail the actual build here
+            abort("\nDanger has failed this build. \nFound #{'error'.danger_pluralize(errors.count)} and I don't have write access to the PR set a PR status.")
+          else
+            puts message
+          end
         end
       end
 
       # Get rid of the previously posted comment, to only have the latest one
       def delete_old_comments!(except: nil, danger_id: 'danger')