Merge remote-tracking branch 'upstream/master' into artifacts-from-ref-and-build-name

* upstream/master: (107 commits)
  Fix external issue tracker "Issues" link leading to 404s
  Fix CHANGELOG entries related to 8.11 release.
  Fix changelog
  Reduce contributions calendar data payload
  Add lock_version to merge_requests table
  Add hover color to emoji icon
  Fix wrong Koding link
  Capitalize mentioned issue timeline notes
  Fix groups sort dropdown alignment
  Use icon helper
  Fix inline emoji text alignment
  Adds response mime type to transaction metric action when it's not HTML
  Moved two 8.11 changelog entries to 8.12
  Fix markdown link in doc_styleguide.md
  Display project icon from default branch
  Reduce number of database queries on builds tab
  Update CHANGELOG
  Update Issue board documentation
  Label list shows all issues (opened or closed) with that label
  Update CHANGELOG
  ...

1 files changed, 48 insertions, 13 deletions

diff --git a/spec/models/merge_request_spec.rb b/spec/models/merge_request_spec.rb
index b6697d0087e..de02de1b9fb 100644
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
@@ -9,7 +9,7 @@ describe MergeRequest, models: true do
     it { is_expected.to belong_to(:target_project).with_foreign_key(:target_project_id).class_name('Project') }
     it { is_expected.to belong_to(:source_project).with_foreign_key(:source_project_id).class_name('Project') }
     it { is_expected.to belong_to(:merge_user).class_name("User") }
-    it { is_expected.to have_one(:merge_request_diff).dependent(:destroy) }
+    it { is_expected.to have_many(:merge_request_diffs).dependent(:destroy) }
   end
 
   describe 'modules' do
@@ -159,7 +159,7 @@ describe MergeRequest, models: true do
 
     context 'when there are MR diffs' do
       it 'delegates to the MR diffs' do
-        merge_request.merge_request_diff = MergeRequestDiff.new
+        merge_request.save
 
         expect(merge_request.merge_request_diff).to receive(:raw_diffs).with(hash_including(options))
 
@@ -316,7 +316,7 @@ describe MergeRequest, models: true do
     end
 
     it "can be removed if the last commit is the head of the source branch" do
-      allow(subject.source_project).to receive(:commit).and_return(subject.diff_head_commit)
+      allow(subject).to receive(:source_branch_head).and_return(subject.diff_head_commit)
 
       expect(subject.can_remove_source_branch?(user)).to be_truthy
     end
@@ -721,12 +721,15 @@ describe MergeRequest, models: true do
 
     let(:commit) { subject.project.commit(sample_commit.id) }
 
-    it "reloads the diff content" do
-      expect(subject.merge_request_diff).to receive(:reload_content)
-
+    it "does not change existing merge request diff" do
+      expect(subject.merge_request_diff).not_to receive(:save_git_content)
       subject.reload_diff
     end
 
+    it "creates new merge request diff" do
+      expect { subject.reload_diff }.to change { subject.merge_request_diffs.count }.by(1)
+    end
+
     it "executs diff cache service" do
       expect_any_instance_of(MergeRequests::MergeRequestDiffCacheService).to receive(:execute).with(subject)
 
@@ -736,13 +739,15 @@ describe MergeRequest, models: true do
     it "updates diff note positions" do
       old_diff_refs = subject.diff_refs
 
-      merge_request_diff = subject.merge_request_diff
-
       # Update merge_request_diff so that #diff_refs will return commit.diff_refs
-      allow(merge_request_diff).to receive(:reload_content) do
-        merge_request_diff.base_commit_sha = commit.parent_id
-        merge_request_diff.start_commit_sha = commit.parent_id
-        merge_request_diff.head_commit_sha = commit.sha
+      allow(subject).to receive(:create_merge_request_diff) do
+        subject.merge_request_diffs.create(
+          base_commit_sha: commit.parent_id,
+          start_commit_sha: commit.parent_id,
+          head_commit_sha: commit.sha
+        )
+
+        subject.merge_request_diff(true)
       end
 
       expect(Notes::DiffPositionUpdateService).to receive(:new).with(
@@ -752,14 +757,31 @@ describe MergeRequest, models: true do
         new_diff_refs: commit.diff_refs,
         paths: note.position.paths
       ).and_call_original
-      expect_any_instance_of(Notes::DiffPositionUpdateService).to receive(:execute).with(note)
 
+      expect_any_instance_of(Notes::DiffPositionUpdateService).to receive(:execute).with(note)
       expect_any_instance_of(DiffNote).to receive(:save).once
 
       subject.reload_diff
     end
   end
 
+  describe '#branch_merge_base_commit' do
+    context 'source and target branch exist' do
+      it { expect(subject.branch_merge_base_commit.sha).to eq('ae73cb07c9eeaf35924a10f713b364d32b2dd34f') }
+      it { expect(subject.branch_merge_base_commit).to be_a(Commit) }
+    end
+
+    context 'when the target branch does not exist' do
+      before do
+        subject.project.repository.raw_repository.delete_branch(subject.target_branch)
+      end
+
+      it 'returns nil' do
+        expect(subject.branch_merge_base_commit).to be_nil
+      end
+    end
+  end
+
   describe "#diff_sha_refs" do
     context "with diffs" do
       subject { create(:merge_request, :with_diffs) }
@@ -890,6 +912,19 @@ describe MergeRequest, models: true do
       expect(merge_request.conflicts_can_be_resolved_in_ui?).to be_falsey
     end
 
+    it 'returns a falsey value when the MR is marked as having conflicts, but has none' do
+      merge_request = create_merge_request('master')
+
+      expect(merge_request.conflicts_can_be_resolved_in_ui?).to be_falsey
+    end
+
+    it 'returns a falsey value when the MR has a missing ref after a force push' do
+      merge_request = create_merge_request('conflict-resolvable')
+      allow(merge_request.conflicts).to receive(:merge_index).and_raise(Rugged::OdbError)
+
+      expect(merge_request.conflicts_can_be_resolved_in_ui?).to be_falsey
+    end
+
     it 'returns a falsey value when the MR does not support new diff notes' do
       merge_request = create_merge_request('conflict-resolvable')
       merge_request.merge_request_diff.update_attributes(start_commit_sha: nil)