Ensure that we're only importing local pull requests

lib/gitlab/github_import/importer.rb

@@ -42,7 +42,7 @@ module Gitlab
                                                     direction: :asc).each do |raw_data|
           pull_request = PullRequestFormatter.new(project, raw_data)
 
-          if pull_request.valid?
+          if !pull_request.cross_project? && pull_request.valid?
             merge_request = MergeRequest.create!(pull_request.attributes)
             import_comments(pull_request.number, merge_request)
             import_comments_on_diff(pull_request.number, merge_request)

lib/gitlab/github_import/pull_request_formatter.rb

@@ -17,6 +17,10 @@ module Gitlab
         }
       end
 
+      def cross_project?
+        source_repo.fork == true
+      end
+
       def number
         raw_data.number
       end
@@ -57,6 +61,10 @@ module Gitlab
         project
       end
 
+      def source_repo
+        raw_data.head.repo
+      end
+
       def source_branch
         source_project.repository.find_branch(raw_data.head.ref)
       end

spec/lib/gitlab/github_import/pull_request_formatter_spec.rb

@@ -124,6 +124,28 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
     end
   end
 
+  describe '#cross_project?' do
+    context 'when source repo is not a fork' do
+      let(:local_repo) { OpenStruct.new(fork: false) }
+      let(:source_branch) { OpenStruct.new(ref: 'feature', repo: local_repo) }
+      let(:raw_data) { OpenStruct.new(base_data.merge(head: source_branch)) }
+
+      it 'returns false' do
+        expect(pull_request.cross_project?).to eq false
+      end
+    end
+
+    context 'when source repo is a fork' do
+      let(:forked_repo) { OpenStruct.new(fork: true) }
+      let(:source_branch) { OpenStruct.new(ref: 'feature', repo: forked_repo) }
+      let(:raw_data) { OpenStruct.new(base_data.merge(head: source_branch)) }
+
+      it 'returns true' do
+        expect(pull_request.cross_project?).to eq true
+      end
+    end
+  end
+
   describe '#number' do
     let(:raw_data) { OpenStruct.new(base_data.merge(number: 1347)) }