Implement merge from forks without satellites

3 files changed, 37 insertions, 11 deletions

diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index aa2137e7469..e32b224eb77 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -206,11 +206,7 @@ class MergeRequest < ActiveRecord::Base
 
   def check_if_can_be_merged
     can_be_merged =
-      if for_fork?
-        raise 'Implement me'
-      else
-        project.repository.can_be_merged?(source_branch, target_branch)
-      end
+      project.repository.can_be_merged?(source_sha, target_branch)
 
     if can_be_merged
       mark_as_mergeable
@@ -274,14 +270,14 @@ class MergeRequest < ActiveRecord::Base
   #
   # see "git diff"
   def to_diff(current_user)
-    raise 'Implement me'
+    target_project.repository.diff_text(target_branch, source_sha)
   end
 
   # Returns the commit as a series of email patches.
   #
   # see "git format-patch"
   def to_patch(current_user)
-    raise 'Implement me'
+    target_project.repository.format_patch(target_branch, source_sha)
   end
 
   def hook_attrs
@@ -432,4 +428,13 @@ class MergeRequest < ActiveRecord::Base
       "Open"
     end
   end
+
+  def target_sha
+    @target_sha ||= target_project.
+      repository.commit(target_branch).sha
+  end
+
+  def source_sha
+    commits.first.sha
+  end
 end
diff --git a/app/models/merge_request_diff.rb b/app/models/merge_request_diff.rb
index df1c2b78758..f3a1c91e75c 100644
--- a/app/models/merge_request_diff.rb
+++ b/app/models/merge_request_diff.rb
@@ -160,10 +160,12 @@ class MergeRequestDiff < ActiveRecord::Base
   private
 
   def compare_result
+    source_sha = merge_request.source_project.commit(source_branch).sha
+
     @compare_result ||= CompareService.new.execute(
       merge_request.author,
-      merge_request.source_project,
-      merge_request.source_branch,
+      merge_request.target_project,
+      source_sha,
       merge_request.target_project,
       merge_request.target_branch,
     )
diff --git a/app/models/repository.rb b/app/models/repository.rb
index 70d416159a7..1924e7ee072 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -422,15 +422,34 @@ class Repository
     }
   end
 
-  def can_be_merged?(source_branch, target_branch)
+  def can_be_merged?(source_sha, target_branch)
     our_commit = rugged.branches[target_branch].target
-    their_commit = rugged.branches[source_branch].target
+    their_commit = rugged.lookup(source_sha)
 
     if our_commit && their_commit
       !rugged.merge_commits(our_commit, their_commit).conflicts?
     end
   end
 
+  def merge(source_sha, target_branch, options = {})
+    our_commit = rugged.branches[target_branch].target
+    their_commit = rugged.lookup(source_sha)
+
+    raise "Invalid merge target" if our_commit.nil?
+    raise "Invalid merge source" if their_commit.nil?
+
+    merge_index = rugged.merge_commits(our_commit, their_commit)
+    return false if merge_index.conflicts?
+
+    actual_options = options.merge(
+      parents: [our_commit, their_commit],
+      tree: merge_index.write_tree(rugged),
+      update_ref: "refs/heads/#{target_branch}"
+    )
+
+    Rugged::Commit.create(rugged, actual_options)
+  end
+
   def search_files(query, ref)
     offset = 2
     args = %W(git grep -i -n --before-context #{offset} --after-context #{offset} #{query} #{ref || root_ref})