Rails3: scm: darcs: fix error of test_fetch_changesets_incremental at unit model test

On Rails 3.1, ActiveRecord::HasManyThroughCantAssociateThroughHasOneOrManyReflection error raises.
For more details, see r7062.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@7118 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/repository_darcs_test.rb

@@ -45,14 +45,19 @@ class RepositoryDarcsTest < ActiveSupport::TestCase
     end
 
     def test_fetch_changesets_incremental
+      assert_equal 0, @repository.changesets.count
       @repository.fetch_changesets
+      @project.reload
+      assert_equal NUM_REV, @repository.changesets.count
+
       # Remove changesets with revision > 3
       @repository.changesets.find(:all).each {|c| c.destroy if c.revision.to_i > 3}
-      @repository.reload
+      @project.reload
       assert_equal 3, @repository.changesets.count
 
       @repository.fetch_changesets
-      assert_equal 6, @repository.changesets.count
+      @project.reload
+      assert_equal NUM_REV, @repository.changesets.count
     end
 
     def test_entries_invalid_revision