Fix Error 500 when browsing projects with no HEAD

Steps to reproduce:
1. Create a project with a README
2. In the actual remote, type: `git symbolic-ref HEAD refs/heads/nowhere`
3. Check that HEAD is gone via `git ls-remote .`
4. Go to the projects page and see the Error 500

Closes https://github.com/gitlabhq/gitlabhq/issues/9484

1 files changed, 19 insertions, 1 deletions

diff --git a/spec/helpers/projects_helper_spec.rb b/spec/helpers/projects_helper_spec.rb
index beb9b4e438e..99abb95d906 100644
--- a/spec/helpers/projects_helper_spec.rb
+++ b/spec/helpers/projects_helper_spec.rb
@@ -22,7 +22,7 @@ describe ProjectsHelper do
 
     let(:user) { create(:user) }
 
-    it "returns false if there are no approipriate permissions" do
+    it "returns false if there are no appropriate permissions" do
       allow(helper).to receive(:can?) { false }
 
       expect(helper.can_change_visibility_level?(project, user)).to be_falsey
@@ -52,4 +52,22 @@ describe ProjectsHelper do
       end
     end
   end
+
+  describe "readme_cache_key" do
+    let(:project) { create(:project) }
+
+    before do
+      helper.instance_variable_set(:@project, project)
+    end
+
+    it "returns a valid cach key" do
+      expect(helper.send(:readme_cache_key)).to eq("#{project.id}-#{project.commit.id}-readme")
+    end
+
+    it "returns a valid cache key if HEAD does not exist" do
+      allow(project).to receive(:commit) { nil }
+
+      expect(helper.send(:readme_cache_key)).to eq("#{project.id}-nil-readme")
+    end
+  end
 end