diff --git a/app/models/repository.rb b/app/models/repository.rb
index 9a6891a90..1ef73a453 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -427,5 +427,9 @@ class Repository < ActiveRecord::Base
     connection.delete("DELETE FROM #{ci} WHERE #{ci}.changeset_id IN (SELECT #{cs}.id FROM #{cs} WHERE #{cs}.repository_id = #{id})")
     connection.delete("DELETE FROM #{cp} WHERE #{cp}.changeset_id IN (SELECT #{cs}.id FROM #{cs} WHERE #{cs}.repository_id = #{id})")
     connection.delete("DELETE FROM #{cs} WHERE #{cs}.repository_id = #{id}")
+    clear_extra_info_of_changesets
+  end
+
+  def clear_extra_info_of_changesets
   end
 end
diff --git a/app/models/repository/git.rb b/app/models/repository/git.rb
index 064a67494..e07e7c804 100644
--- a/app/models/repository/git.rb
+++ b/app/models/repository/git.rb
@@ -255,4 +255,15 @@ class Repository::Git < Repository
       :order => 'committed_on DESC'
     )
   end
+
+  def clear_extra_info_of_changesets
+    return if extra_info.nil?
+    v = extra_info["extra_report_last_commit"]
+    write_attribute(:extra_info, nil)
+    h = {}
+    h["extra_report_last_commit"] = v
+    merge_extra_info(h)
+    self.save
+  end
+  private :clear_extra_info_of_changesets
 end
diff --git a/test/unit/repository_git_test.rb b/test/unit/repository_git_test.rb
index cfb0f486c..fa2f8bce6 100644
--- a/test/unit/repository_git_test.rb
+++ b/test/unit/repository_git_test.rb
@@ -217,6 +217,40 @@ class RepositoryGitTest < ActiveSupport::TestCase
       assert_equal h1, h2
     end
 
+    def test_keep_extra_report_last_commit_in_clear_changesets
+      assert_nil @repository.extra_info
+      h = {}
+      h["extra_report_last_commit"] = 1
+      @repository.merge_extra_info(h)
+      @repository.save
+      @project.reload
+
+      assert_equal 0, @repository.changesets.count
+      @repository.fetch_changesets
+      @project.reload
+
+      assert_equal NUM_REV, @repository.changesets.count
+      @repository.send(:clear_changesets)
+      assert_equal 1, @repository.extra_info.size
+      assert_equal 1, @repository.extra_info["extra_report_last_commit"]
+    end
+
+    def test_refetch_after_clear_changesets
+      assert_nil @repository.extra_info
+      assert_equal 0, @repository.changesets.count
+      @repository.fetch_changesets
+      @project.reload
+      assert_equal NUM_REV, @repository.changesets.count
+
+      @repository.send(:clear_changesets)
+      @project.reload
+      assert_equal 0, @repository.changesets.count
+
+      @repository.fetch_changesets
+      @project.reload
+      assert_equal NUM_REV, @repository.changesets.count
+    end
+
     def test_parents
       assert_equal 0, @repository.changesets.count
       @repository.fetch_changesets