4 files changed, 26 insertions, 12 deletions
diff --git a/app/models/commit.rb b/app/models/commit.rb
index 23b5e38336c..492f6be1ce3 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -164,6 +164,14 @@ class Commit
     @committer ||= User.find_by_any_email(committer_email)
   end
 
+  def parents
+    @parents ||= parent_ids.map { |id| project.commit(id) }
+  end
+
+  def parent
+    @parent ||= project.commit(self.parent_id) if self.parent_id
+  end
+
   def notes
     project.notes.for_commit_id(self.id)
   end
@@ -181,10 +189,6 @@ class Commit
     @raw.short_id(7)
   end
 
-  def parents
-    @parents ||= Commit.decorate(super, project)
-  end
-
   def ci_commit
     project.ci_commit(sha)
   end
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 0042b95c4f1..21861a46a84 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -40,7 +40,7 @@ class MergeRequest < ActiveRecord::Base
   after_create :create_merge_request_diff
   after_update :update_merge_request_diff
 
-  delegate :commits, :diffs, :last_commit, :last_commit_short_sha, to: :merge_request_diff, prefix: nil
+  delegate :commits, :diffs, to: :merge_request_diff, prefix: nil
 
   # When this attribute is true some MR validation is ignored
   # It allows us to close or modify broken merge requests
@@ -157,6 +157,18 @@ class MergeRequest < ActiveRecord::Base
     reference
   end
 
+  def last_commit
+    merge_request_diff ? merge_request_diff.last_commit : compare_commits.last
+  end 
+
+  def first_commit
+    merge_request_diff ? merge_request_diff.first_commit : compare_commits.first
+  end 
+
+  def last_commit_short_sha
+    last_commit.short_id
+  end
+
   def validate_branches
     if target_project == source_project && target_branch == source_branch
       errors.add :branch_conflict, "You can not use same project/branch for source and target"
diff --git a/app/models/merge_request_diff.rb b/app/models/merge_request_diff.rb
index bc2d691ece0..6575d0bc81f 100644
--- a/app/models/merge_request_diff.rb
+++ b/app/models/merge_request_diff.rb
@@ -55,6 +55,10 @@ class MergeRequestDiff < ActiveRecord::Base
     commits.first
   end
 
+  def first_commit
+    commits.last
+  end
+
   def last_commit_short_sha
     @last_commit_short_sha ||= last_commit.short_id
   end
diff --git a/app/models/repository.rb b/app/models/repository.rb
index 921e1a9e426..e2d4f74407f 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -312,13 +312,7 @@ class Repository
   end
 
   def blob_for_diff(commit, diff)
-    file = blob_at(commit.id, diff.new_path)
-
-    unless file
-      file = prev_blob_for_diff(commit, diff)
-    end
-
-    file
+    blob_at(commit.id, diff.file_path)
   end
 
   def prev_blob_for_diff(commit, diff)