[#446] aliased projects should have same default branch

app/controllers/projects/projects_controller.rb

@@ -48,9 +48,7 @@ class Projects::ProjectsController < Projects::BaseController
   end
 
   def edit
-    @project_aliases = Project.where.not(id: @project.id).
-      where('alias_from_id IN (:ids) OR id IN (:ids)', { ids: [@project.alias_from_id, @project.id] }).
-      paginate(page: current_page)
+    @project_aliases = Project.project_aliases(@project).paginate(page: current_page)
   end
 
   def create

app/models/concerns/project/default_branch.rb

@@ -63,7 +63,10 @@ module Project::DefaultBranch
 
   # Private: Set git head.
   def set_new_git_head
-    `cd #{path} && git symbolic-ref HEAD refs/heads/#{self.default_branch}` if self.default_branch_changed? && self.repo.branches.map(&:name).include?(self.default_branch)
+    if self.default_branch_changed? && self.repo.branches.map(&:name).include?(self.default_branch)
+      self.repo.git.send(:'symbolic-ref', {}, 'HEAD', "refs/heads/#{self.default_branch}")
+      Project.project_aliases(self).update_all default_branch: self.default_branch
+    end
   end
 
   # Private: Validation for checking that the default branch is exist.

app/models/project.rb

@@ -93,6 +93,11 @@ class Project < ActiveRecord::Base
       (projects.owner_id in (?) AND projects.owner_type = 'User')", group_owner_ids, user_owner_ids)
   }
 
+  scope :project_aliases, ->(project)  {
+    where.not(id: project.id).
+      where('alias_from_id IN (:ids) OR id IN (:ids)', { ids: [project.alias_from_id, project.id].compact })
+  }
+
   before_validation :truncate_name, on: :create
   before_save -> { self.owner_uname = owner.uname if owner_uname.blank? || owner_id_changed? || owner_type_changed? }
   before_create :set_maintainer

spec/models/project_spec.rb

@@ -4,7 +4,7 @@ describe Project do
   before { stub_symlink_methods }
 
   context '#fork' do
-    let(:root_project)        { FactoryGirl.create(:project) }
+    let(:root_project)        { FactoryGirl.create(:project_with_commit) }
     let(:child_project)       { root_project.fork(FactoryGirl.create(:user)) }
     let(:child_child_project) { child_project.fork(FactoryGirl.create(:user)) }
     let(:alias_project)       { root_project.fork(FactoryGirl.create(:user), is_alias: true) }
@@ -41,6 +41,20 @@ describe Project do
         expect(alias_alias_project.alias_from).to eq(root_project)
         expect{ Grit::Repo.new(alias_alias_project.path) }.to_not raise_exception
       end
+
+      it 'ensures that aliased projects have a same default branch' do
+        new_default_branch = 'conflicts'
+        alias_project.update_attributes default_branch: new_default_branch
+        expect(alias_project.parent.default_branch).to eq(new_default_branch)
+      end
+
+      it 'ensures that forked project allowed to have another default branch' do
+        fill_project root_project
+        fill_project child_project
+        new_default_branch = 'conflicts'
+        child_project.update_attributes default_branch: new_default_branch
+        expect(child_project.parent.default_branch).to_not eq(new_default_branch)
+      end
     end
 
     context 'for destroy' do