Fix GFM helper to raise an exception when @Project is not set

app/helpers/application_helper.rb

@@ -44,6 +44,7 @@ module ApplicationHelper
   def gfm(text, html_options = {})
     return text if text.nil?
+    raise "@project is not set" if @project.nil?
     # Extract pre blocks
     # from http://github.github.com/github-flavored-markdown/

spec/helpers/gitlab_flavored_markdown_spec.rb

@@ -10,6 +10,12 @@ describe ApplicationHelper do
   end
   describe "#gfm" do
+    it "should raiase an error if @project is not set" do
+      @project = nil
+
+      expect { gfm("foo") }.to raise_error
+    end
+
     describe "referencing a commit" do
       it "should link using a full id" do
         gfm("Reverts changes from #{@commit.id}").should == "Reverts changes from #{link_to @commit.id, project_commit_path(@project, :id => @commit.id), :title => "Commit: #{@commit.author_name} - #{@commit.title}", :class => "gfm gfm-commit "}"