Fix conflict resolution from corrupted upstreamfix-conflict-resolution-with-corrupt-repos

I don't know why this happens exactly, but given an upstream and fork repository
from a customer, both of which required GC, resolving conflicts would corrupt
the fork so badly that it couldn't be cloned.

This isn't a perfect fix for that case, because the MR may still need to be
merged manually, but it does ensure that the repository is at least usable.

My best guess is that when we generate the index for the conflict
resolution (which we previously did in the target project), we obtain a
reference to an OID that doesn't exist in the source, even though we already
fetch the refs from the target into the source.

Explicitly setting the source project as the place to get the merge index from
seems to prevent repository corruption in this way.

1 files changed, 0 insertions, 65 deletions

diff --git a/spec/models/merge_request_spec.rb b/spec/models/merge_request_spec.rb
index ef349530761..67f715ee25e 100644
--- a/spec/models/merge_request_spec.rb
+++ b/spec/models/merge_request_spec.rb
@@ -1310,71 +1310,6 @@ describe MergeRequest, models: true do
     end
   end
 
-  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|
-        mr.mark_as_unmergeable
-      end
-    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(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)
-
-      expect(merge_request.conflicts_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(merge_request.conflicts_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(merge_request.conflicts_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(merge_request.conflicts_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(merge_request.conflicts_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(merge_request.conflicts_can_be_resolved_in_ui?).to be_truthy
-    end
-  end
-
   describe "#source_project_missing?" do
     let(:project)      { create(:empty_project) }
     let(:fork_project) { create(:empty_project, forked_from_project: project) }