Implemented rebase strategy

src/main/scala/gitbucket/core/controller/PullRequestsController.scala

@@ -261,9 +261,18 @@ trait PullRequestsControllerBase extends ControllerBase {
 
             // merge git repository
             // TODO Implement merge strategy!
+            println(form.strategy)
+            form.strategy match {
+              case "merge-commit" =>
+                println("** merge commit **")
                 mergePullRequest(git, pullreq.branch, issueId,
                   s"Merge pull request #${issueId} from ${pullreq.requestUserName}/${pullreq.requestBranch}\n\n" + form.message,
                   new PersonIdent(loginAccount.fullName, loginAccount.mailAddress))
+              case "rebase" =>
+                println("** rebase **")
+                rebasePullRequest(git, pullreq.branch, issueId,
+                  new PersonIdent(loginAccount.fullName, loginAccount.mailAddress))
+            }
 
             val (commits, _) = getRequestCompareInfo(owner, name, pullreq.commitIdFrom,
               pullreq.requestUserName, pullreq.requestRepositoryName, pullreq.commitIdTo)

src/main/scala/gitbucket/core/service/MergeService.scala

@@ -35,11 +35,16 @@ trait MergeService {
     }
   }
 
-  /** merge pull request */
+  /** merge the pull request with a merge commit */
   def mergePullRequest(git: Git, branch: String, issueId: Int, message: String, committer: PersonIdent): Unit = {
     new MergeCacheInfo(git, branch, issueId).merge(message, committer)
   }
 
+  /** rebase to the pull request branch */
+  def rebasePullRequest(git: Git, branch: String, issueId: Int, committer: PersonIdent): Unit = {
+    new MergeCacheInfo(git, branch, issueId).rebase(committer)
+  }
+
   /** fetch remote branch to my repository refs/pull/{issueId}/head */
   def fetchAsPullRequest(userName: String, repositoryName: String, requestUserName: String, requestRepositoryName: String, requestBranch:String, issueId:Int){
     using(Git.open(getRepositoryDir(userName, repositoryName))){ git =>
@@ -209,6 +214,14 @@ object MergeService{
       Util.updateRefs(repository, s"refs/heads/${branch}", mergeCommitId, false, committer, Some("merged"))
     }
 
+    def rebase(committer: PersonIdent) = {
+      if(checkConflict()){
+        throw new RuntimeException("This pull request can't merge automatically.")
+      }
+      val mergeTipCommit = using(new RevWalk( repository ))(_.parseCommit( mergeTip ))
+      Util.updateRefs(repository, s"refs/heads/${branch}", mergeTipCommit.getId, false, committer, Some("merged"))
+    }
+
     // return treeId
     private def createMergeCommit(treeId: ObjectId, committer: PersonIdent, message: String) =
       Util.createMergeCommit(repository, treeId, committer, message, Seq[ObjectId](mergeBaseTip, mergeTip))

src/main/twirl/gitbucket/core/pulls/mergeguide.scala.html

@@ -223,7 +223,7 @@ $(function(){
 
   $('.merge-strategy').click(function(){
     $('button#merge-strategy-btn > span.strong').text($(this).find('strong').text());
-    $('hidden[name=strategy]').val($(this).data('value'));
+    $('input[name=strategy]').val($(this).data('value'));
   });
 });
 </script>