Fix issues importing forked projects

6 files changed, 82 insertions, 7 deletions

diff --git a/lib/gitlab/import_export/hash_util.rb b/lib/gitlab/import_export/hash_util.rb
new file mode 100644
index 00000000000..d4adeeb3797
--- /dev/null
+++ b/lib/gitlab/import_export/hash_util.rb
@@ -0,0 +1,25 @@
+module Gitlab
+  module ImportExport
+    class HashUtil
+      def self.deep_symbolize_array!(array)
+        return if array.blank?
+
+        array.map! do |hash|
+          hash.deep_symbolize_keys!
+
+          yield(hash) if block_given?
+
+          hash
+        end
+      end
+
+      def self.deep_symbolize_array_with_date!(array)
+        self.deep_symbolize_array!(array) do |hash|
+          hash.select { |k, _v| k.to_s.end_with?('_date') }.each do |key, value|
+            hash[key] = Time.zone.parse(value)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/import_export/import_export.yml b/lib/gitlab/import_export/import_export.yml
index ab74c8782f6..f69288f7d67 100644
--- a/lib/gitlab/import_export/import_export.yml
+++ b/lib/gitlab/import_export/import_export.yml
@@ -89,3 +89,5 @@ methods:
     - :type
   merge_request_diff:
     - :utf8_st_diffs
+  merge_requests:
+    - :diff_head_sha
diff --git a/lib/gitlab/import_export/importer.rb b/lib/gitlab/import_export/importer.rb
index 063ce74ecad..fbdd74788bc 100644
--- a/lib/gitlab/import_export/importer.rb
+++ b/lib/gitlab/import_export/importer.rb
@@ -9,7 +9,7 @@ module Gitlab
       end
 
       def execute
-        if import_file && check_version! && [project_tree, avatar_restorer, repo_restorer, wiki_restorer, uploads_restorer].all?(&:restore)
+        if import_file && check_version! && [repo_restorer, wiki_restorer, project_tree, avatar_restorer, uploads_restorer].all?(&:restore)
           project_tree.restored_project
         else
           raise Projects::ImportService::Error.new(@shared.errors.join(', '))
diff --git a/lib/gitlab/import_export/merge_request_parser.rb b/lib/gitlab/import_export/merge_request_parser.rb
new file mode 100644
index 00000000000..c20adc20bfd
--- /dev/null
+++ b/lib/gitlab/import_export/merge_request_parser.rb
@@ -0,0 +1,41 @@
+module Gitlab
+  module ImportExport
+    class MergeRequestParser
+      FORKED_PROJECT_ID = -1
+
+      def initialize(project, diff_head_sha, merge_request, relation_hash)
+        @project = project
+        @diff_head_sha = diff_head_sha
+        @merge_request = merge_request
+        @relation_hash = relation_hash
+      end
+
+      def parse!
+        if fork_merge_request? && @diff_head_sha
+          @merge_request.source_project_id = @relation_hash['project_id']
+
+          fetch_ref unless branch_exists?(@merge_request.source_branch)
+          create_target_branch unless branch_exists?(@merge_request.target_branch)
+        end
+
+        @merge_request
+      end
+
+      def create_target_branch
+        @project.repository.create_branch(@merge_request.target_branch, @merge_request.target_branch_sha)
+      end
+
+      def fetch_ref
+        @project.repository.fetch_ref(@project.repository.path, @diff_head_sha, @merge_request.source_branch)
+      end
+
+      def branch_exists?(branch_name)
+        @project.repository.branch_exists?(branch_name)
+      end
+
+      def fork_merge_request?
+        @relation_hash['source_project_id'] == FORKED_PROJECT_ID
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/import_export/project_tree_restorer.rb b/lib/gitlab/import_export/project_tree_restorer.rb
index cda6ddf0443..df21ff22216 100644
--- a/lib/gitlab/import_export/project_tree_restorer.rb
+++ b/lib/gitlab/import_export/project_tree_restorer.rb
@@ -119,7 +119,7 @@ module Gitlab
                                                        relation_hash: parsed_relation_hash(relation_hash),
                                                        members_mapper: members_mapper,
                                                        user: @user,
-                                                       project_id: restored_project.id)
+                                                       project: restored_project)
         end.compact
 
         relation_hash_list.is_a?(Array) ? relation_array : relation_array.first
diff --git a/lib/gitlab/import_export/relation_factory.rb b/lib/gitlab/import_export/relation_factory.rb
index d44563333a5..fb43e7ccdbb 100644
--- a/lib/gitlab/import_export/relation_factory.rb
+++ b/lib/gitlab/import_export/relation_factory.rb
@@ -29,11 +29,12 @@ module Gitlab
         new(*args).create
       end
 
-      def initialize(relation_sym:, relation_hash:, members_mapper:, user:, project_id:)
+      def initialize(relation_sym:, relation_hash:, members_mapper:, user:, project:)
         @relation_name = OVERRIDES[relation_sym] || relation_sym
-        @relation_hash = relation_hash.except('noteable_id').merge('project_id' => project_id)
+        @relation_hash = relation_hash.except('noteable_id').merge('project_id' => project.id)
         @members_mapper = members_mapper
         @user = user
+        @project = project
         @imported_object_retries = 0
       end
 
@@ -66,7 +67,7 @@ module Gitlab
         remove_encrypted_attributes!
 
         @relation_hash['data'].deep_symbolize_keys! if @relation_name == :events && @relation_hash['data']
-        set_st_diffs if @relation_name == :merge_request_diff
+        set_st_diff_commits if @relation_name == :merge_request_diff
       end
 
       def update_user_references
@@ -105,6 +106,8 @@ module Gitlab
           imported_object do |object|
             object.commit_id = nil
           end
+        elsif @relation_name == :merge_requests
+          MergeRequestParser.new(@project, @relation_hash.delete('diff_head_sha'), imported_object, @relation_hash).parse!
         else
           imported_object
         end
@@ -115,7 +118,7 @@ module Gitlab
 
         # If source and target are the same, populate them with the new project ID.
         if @relation_hash['source_project_id']
-          @relation_hash['source_project_id'] = same_source_and_target? ? project_id : -1
+          @relation_hash['source_project_id'] = same_source_and_target? ? project_id : MergeRequestParser::FORKED_PROJECT_ID
         end
 
         # project_id may not be part of the export, but we always need to populate it if required.
@@ -166,6 +169,7 @@ module Gitlab
       def imported_object
         yield(existing_or_new_object) if block_given?
         existing_or_new_object.importing = true if existing_or_new_object.respond_to?(:importing)
+
         existing_or_new_object
       rescue ActiveRecord::RecordNotUnique
         # as the operation is not atomic, retry in the unlikely scenario an INSERT is
@@ -188,8 +192,11 @@ module Gitlab
                                                                                relation_class: relation_class)
       end
 
-      def set_st_diffs
+      def set_st_diff_commits
         @relation_hash['st_diffs'] = @relation_hash.delete('utf8_st_diffs')
+
+        HashUtil.deep_symbolize_array!(@relation_hash['st_diffs'])
+        HashUtil.deep_symbolize_array_with_date!(@relation_hash['st_commits'])
       end
 
       def existing_or_new_object