Fix importing PR's from GitHub when the source repo was removed

lib/gitlab/github_import/importer.rb

@@ -45,12 +45,15 @@ module Gitlab
                                                     direction: :asc).each do |raw_data|
           pull_request = PullRequestFormatter.new(project, raw_data)
 
-          if !pull_request.cross_project? && pull_request.valid?
-            merge_request = MergeRequest.create!(pull_request.attributes)
+          if pull_request.valid?
+            merge_request = MergeRequest.new(pull_request.attributes)
+
+            if merge_request.save
               import_comments(pull_request.number, merge_request)
               import_comments_on_diff(pull_request.number, merge_request)
             end
           end
+        end
 
         true
       rescue ActiveRecord::RecordInvalid => e

lib/gitlab/github_import/pull_request_formatter.rb

@@ -17,16 +17,12 @@ module Gitlab
         }
       end
 
-      def cross_project?
-        source_repo.id != target_repo.id
-      end
-
       def number
         raw_data.number
       end
 
       def valid?
-        source_branch.present? && target_branch.present?
+        !cross_project? && source_branch.present? && target_branch.present?
       end
 
       private
@@ -53,6 +49,10 @@ module Gitlab
         raw_data.body || ""
       end
 
+      def cross_project?
+        source_repo.present? && target_repo.present? && source_repo.id != target_repo.id
+      end
+
       def description
         formatter.author_line(author) + body
       end

spec/lib/gitlab/github_import/pull_request_formatter_spec.rb

@@ -127,34 +127,6 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
     end
   end
 
-  describe '#cross_project?' do
-    context 'when source, and target repositories are the same' do
-      let(:raw_data) { OpenStruct.new(base_data) }
-
-      it 'returns false' do
-        expect(pull_request.cross_project?).to eq false
-      end
-    end
-
-    context 'when source repo is a fork' do
-      let(:source_repo) { OpenStruct.new(id: 2, fork: true) }
-      let(:raw_data) { OpenStruct.new(base_data) }
-
-      it 'returns true' do
-        expect(pull_request.cross_project?).to eq true
-      end
-    end
-
-    context 'when target repo is a fork' do
-      let(:target_repo) { OpenStruct.new(id: 2, fork: true) }
-      let(:raw_data) { OpenStruct.new(base_data) }
-
-      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)) }
 
@@ -166,7 +138,8 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
   describe '#valid?' do
     let(:invalid_branch) { OpenStruct.new(ref: 'invalid-branch') }
 
-    context 'when source and target branches exists' do
+    context 'when source, and target repositories are the same' do
+      context 'and source and target branches exists' do
         let(:raw_data) { OpenStruct.new(base_data.merge(head: source_branch, base: target_branch)) }
 
         it 'returns true' do
@@ -174,7 +147,7 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
         end
       end
 
-    context 'when source branch doesn not exists' do
+      context 'and source branch doesn not exists' do
         let(:raw_data) { OpenStruct.new(base_data.merge(head: invalid_branch, base: target_branch)) }
 
         it 'returns false' do
@@ -182,7 +155,7 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
         end
       end
 
-    context 'when target branch doesn not exists' do
+      context 'and target branch doesn not exists' do
         let(:raw_data) { OpenStruct.new(base_data.merge(head: source_branch, base: invalid_branch)) }
 
         it 'returns false' do
@@ -190,4 +163,23 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
         end
       end
     end
+
+    context 'when source repo is a fork' do
+      let(:source_repo) { OpenStruct.new(id: 2, fork: true) }
+      let(:raw_data) { OpenStruct.new(base_data) }
+
+      it 'returns false' do
+        expect(pull_request.valid?).to eq false
+      end
+    end
+
+    context 'when target repo is a fork' do
+      let(:target_repo) { OpenStruct.new(id: 2, fork: true) }
+      let(:raw_data) { OpenStruct.new(base_data) }
+
+      it 'returns false' do
+        expect(pull_request.valid?).to eq false
+      end
+    end
+  end
 end