Merge branch 'fix-conflict-resolution-with-corrupt-repos' into 'master'

Fix conflict resolution from corrupted upstream

Closes gitlab-ee#2128

See merge request !11298

Conflicts:
	app/models/merge_request.rb
	spec/models/merge_request_spec.rb

6 files changed, 117 insertions, 26 deletions

diff --git a/spec/controllers/projects/merge_requests_controller_spec.rb b/spec/controllers/projects/merge_requests_controller_spec.rb
index 964246b580c..fdee8c6e970 100644
--- a/spec/controllers/projects/merge_requests_controller_spec.rb
+++ b/spec/controllers/projects/merge_requests_controller_spec.rb
@@ -915,7 +915,9 @@ describe Projects::MergeRequestsController do
       end
 
       it 'returns the file in JSON format' do
-        content = merge_request_with_conflicts.conflicts.file_for_path(path, path).content
+        content = MergeRequests::Conflicts::ListService.new(merge_request_with_conflicts).
+                    file_for_path(path, path).
+                    content
 
         expect(json_response).to include('old_path' => path,
                                          'new_path' => path,
@@ -1039,11 +1041,15 @@ describe Projects::MergeRequestsController do
 
     context 'when a file has identical content to the conflict' do
       before do
+        content = MergeRequests::Conflicts::ListService.new(merge_request_with_conflicts).
+                    file_for_path('files/ruby/popen.rb', 'files/ruby/popen.rb').
+                    content
+
         resolved_files = [
           {
             'new_path' => 'files/ruby/popen.rb',
             'old_path' => 'files/ruby/popen.rb',
-            'content' => merge_request_with_conflicts.conflicts.file_for_path('files/ruby/popen.rb', 'files/ruby/popen.rb').content
+            'content' => content
           }, {
             'new_path' => 'files/ruby/regex.rb',
             'old_path' => 'files/ruby/regex.rb',
diff --git a/spec/lib/gitlab/conflict/file_collection_spec.rb b/spec/lib/gitlab/conflict/file_collection_spec.rb
index 39d892c18c0..27f23ea70dc 100644
--- a/spec/lib/gitlab/conflict/file_collection_spec.rb
+++ b/spec/lib/gitlab/conflict/file_collection_spec.rb
@@ -2,7 +2,7 @@ require 'spec_helper'
 
 describe Gitlab::Conflict::FileCollection, lib: true do
   let(:merge_request) { create(:merge_request, source_branch: 'conflict-resolvable', target_branch: 'conflict-start') }
-  let(:file_collection) { Gitlab::Conflict::FileCollection.new(merge_request) }
+  let(:file_collection) { described_class.read_only(merge_request) }
 
   describe '#files' do
     it 'returns an array of Conflict::Files' do
diff --git a/spec/models/merge_request_spec.rb b/spec/models/merge_request_spec.rb
index a6fd89c8e5d..bbdf758cc61 100644
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
@@ -1315,6 +1315,7 @@ describe MergeRequest, models: true do
     end
   end
 
+<<<<<<< HEAD
   describe '#conflicts_can_be_resolved_in_ui?' do
     def create_merge_request(source_branch)
       create(:merge_request, source_branch: source_branch, target_branch: 'conflict-start') do |mr|
@@ -1387,6 +1388,8 @@ describe MergeRequest, models: true do
     end
   end
 
+=======
+>>>>>>> e4261fe3... Merge branch 'fix-conflict-resolution-with-corrupt-repos' into 'master'

   describe "#source_project_missing?" do
     let(:project)      { create(:empty_project) }
     let(:fork_project) { create(:empty_project, forked_from_project: project) }
diff --git a/spec/presenters/merge_request_presenter_spec.rb b/spec/presenters/merge_request_presenter_spec.rb
index e599ddaf943..44720fc4448 100644
--- a/spec/presenters/merge_request_presenter_spec.rb
+++ b/spec/presenters/merge_request_presenter_spec.rb
@@ -73,12 +73,12 @@ describe MergeRequestPresenter do
   describe '#conflict_resolution_path' do
     let(:project) { create :empty_project }
     let(:user) { create :user }
-    let(:path) { described_class.new(resource, current_user: user).conflict_resolution_path }
+    let(:presenter) { described_class.new(resource, current_user: user) }
+    let(:path) { presenter.conflict_resolution_path }
 
     context 'when MR cannot be resolved in UI' do
       it 'does not return conflict resolution path' do
-        allow(resource).to receive(:conflicts_can_be_resolved_in_ui?) { true }
-        allow(resource).to receive(:conflicts_can_be_resolved_by?).with(user) { false }
+        allow(presenter).to receive_message_chain(:conflicts, :can_be_resolved_in_ui?) { false }
 
         expect(path).to be_nil
       end
@@ -86,8 +86,8 @@ describe MergeRequestPresenter do
 
     context 'when conflicts cannot be resolved by user' do
       it 'does not return conflict resolution path' do
-        allow(resource).to receive(:conflicts_can_be_resolved_in_ui?) { false }
-        allow(resource).to receive(:conflicts_can_be_resolved_by?).with(user) { true }
+        allow(presenter).to receive_message_chain(:conflicts, :can_be_resolved_in_ui?) { true }
+        allow(presenter).to receive_message_chain(:conflicts, :can_be_resolved_by?).with(user) { false }
 
         expect(path).to be_nil
       end
@@ -95,8 +95,8 @@ describe MergeRequestPresenter do
 
     context 'when able to access conflict resolution UI' do
       it 'does return conflict resolution path' do
-        allow(resource).to receive(:conflicts_can_be_resolved_in_ui?) { true }
-        allow(resource).to receive(:conflicts_can_be_resolved_by?).with(user) { true }
+        allow(presenter).to receive_message_chain(:conflicts, :can_be_resolved_in_ui?) { true }
+        allow(presenter).to receive_message_chain(:conflicts, :can_be_resolved_by?).with(user) { true }
 
         expect(path)
           .to eq("/#{project.full_path}/merge_requests/#{resource.iid}/conflicts")
diff --git a/spec/services/merge_requests/conflicts/list_service_spec.rb b/spec/services/merge_requests/conflicts/list_service_spec.rb
new file mode 100644
index 00000000000..e8a305d6130
--- /dev/null
+++ b/spec/services/merge_requests/conflicts/list_service_spec.rb
@@ -0,0 +1,73 @@
+require 'spec_helper'
+
+describe MergeRequests::Conflicts::ListService do
+  describe '#can_be_resolved_in_ui?' do
+    def create_merge_request(source_branch)
+      create(:merge_request, source_branch: source_branch, target_branch: 'conflict-start') do |mr|
+        mr.mark_as_unmergeable
+      end
+    end
+
+    def conflicts_service(merge_request)
+      described_class.new(merge_request)
+    end
+
+    it 'returns a falsey value when the MR can be merged without conflicts' do
+      merge_request = create_merge_request('master')
+      merge_request.mark_as_mergeable
+
+      expect(conflicts_service(merge_request).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(conflicts_service(merge_request).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')
+      service = conflicts_service(merge_request)
+      allow(service.conflicts).to receive(:merge_index).and_raise(Rugged::OdbError)
+
+      expect(service.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)
+
+      expect(conflicts_service(merge_request).can_be_resolved_in_ui?).to be_falsey
+    end
+
+    it 'returns a falsey value when the conflicts contain a large file' do
+      merge_request = create_merge_request('conflict-too-large')
+
+      expect(conflicts_service(merge_request).can_be_resolved_in_ui?).to be_falsey
+    end
+
+    it 'returns a falsey value when the conflicts contain a binary file' do
+      merge_request = create_merge_request('conflict-binary-file')
+
+      expect(conflicts_service(merge_request).can_be_resolved_in_ui?).to be_falsey
+    end
+
+    it 'returns a falsey value when the conflicts contain a file edited in one branch and deleted in another' do
+      merge_request = create_merge_request('conflict-missing-side')
+
+      expect(conflicts_service(merge_request).can_be_resolved_in_ui?).to be_falsey
+    end
+
+    it 'returns a truthy value when the conflicts are resolvable in the UI' do
+      merge_request = create_merge_request('conflict-resolvable')
+
+      expect(conflicts_service(merge_request).can_be_resolved_in_ui?).to be_truthy
+    end
+
+    it 'returns a truthy value when the conflicts have to be resolved in an editor' do
+      merge_request = create_merge_request('conflict-contains-conflict-markers')
+
+      expect(conflicts_service(merge_request).can_be_resolved_in_ui?).to be_truthy
+    end
+  end
+end
diff --git a/spec/services/merge_requests/resolve_service_spec.rb b/spec/services/merge_requests/conflicts/resolve_service_spec.rb
index 3afd6b92900..19e8d5cc5f1 100644
--- a/spec/services/merge_requests/resolve_service_spec.rb
+++ b/spec/services/merge_requests/conflicts/resolve_service_spec.rb
@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-describe MergeRequests::ResolveService do
+describe MergeRequests::Conflicts::ResolveService do
   let(:user) { create(:user) }
   let(:project) { create(:project, :repository) }
 
@@ -24,6 +24,8 @@ describe MergeRequests::ResolveService do
   end
 
   describe '#execute' do
+    let(:service) { described_class.new(merge_request) }
+
     context 'with section params' do
       let(:params) do
         {
@@ -50,7 +52,7 @@ describe MergeRequests::ResolveService do
 
       context 'when the source and target project are the same' do
         before do
-          described_class.new(project, user, params).execute(merge_request)
+          service.execute(user, params)
         end
 
         it 'creates a commit with the message' do
@@ -74,15 +76,26 @@ describe MergeRequests::ResolveService do
             branch_name: 'conflict-start')
         end
 
-        before do
-          described_class.new(fork_project, user, params).execute(merge_request_from_fork)
+        def resolve_conflicts
+          described_class.new(merge_request_from_fork).execute(user, params)
+        end
+
+        it 'gets conflicts from the source project' do
+          expect(fork_project.repository.rugged).to receive(:merge_commits).and_call_original
+          expect(project.repository.rugged).not_to receive(:merge_commits)
+
+          resolve_conflicts
         end
 
         it 'creates a commit with the message' do
+          resolve_conflicts
+
           expect(merge_request_from_fork.source_branch_head.message).to eq(params[:commit_message])
         end
 
         it 'creates a commit with the correct parents' do
+          resolve_conflicts
+
           expect(merge_request_from_fork.source_branch_head.parents.map(&:id)).
             to eq(['404fa3fc7c2c9b5dacff102f353bdf55b1be2813',
                    target_head])
@@ -115,7 +128,7 @@ describe MergeRequests::ResolveService do
       end
 
       before do
-        described_class.new(project, user, params).execute(merge_request)
+        service.execute(user, params)
       end
 
       it 'creates a commit with the message' do
@@ -154,15 +167,15 @@ describe MergeRequests::ResolveService do
         }
       end
 
-      let(:service) { described_class.new(project, user, invalid_params) }
-
       it 'raises a MissingResolution error' do
-        expect { service.execute(merge_request) }.
+        expect { service.execute(user, invalid_params) }.
           to raise_error(Gitlab::Conflict::File::MissingResolution)
       end
     end
 
     context 'when the content of a file is unchanged' do
+      let(:list_service) { MergeRequests::Conflicts::ListService.new(merge_request) }
+
       let(:invalid_params) do
         {
           files: [
@@ -173,17 +186,15 @@ describe MergeRequests::ResolveService do
             }, {
               old_path: 'files/ruby/regex.rb',
               new_path: 'files/ruby/regex.rb',
-              content: merge_request.conflicts.file_for_path('files/ruby/regex.rb', 'files/ruby/regex.rb').content
+              content: list_service.conflicts.file_for_path('files/ruby/regex.rb', 'files/ruby/regex.rb').content
             }
           ],
           commit_message: 'This is a commit message!'
         }
       end
 
-      let(:service) { described_class.new(project, user, invalid_params) }
-
       it 'raises a MissingResolution error' do
-        expect { service.execute(merge_request) }.
+        expect { service.execute(user, invalid_params) }.
           to raise_error(Gitlab::Conflict::File::MissingResolution)
       end
     end
@@ -202,11 +213,9 @@ describe MergeRequests::ResolveService do
         }
       end
 
-      let(:service) { described_class.new(project, user, invalid_params) }
-
       it 'raises a MissingFiles error' do
-        expect { service.execute(merge_request) }.
-          to raise_error(MergeRequests::ResolveService::MissingFiles)
+        expect { service.execute(user, invalid_params) }.
+          to raise_error(described_class::MissingFiles)
       end
     end
   end