Fixes r2707.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2708 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/tasks/migrate_from_mantis.rake

@@ -196,7 +196,12 @@ task :migrate_from_mantis => :environment do
       end
       
       def read(*args)
-        content
+      	if @read_finished
+      		nil
+      	else
+      		@read_finished = true
+      		content
+      	end
       end
     end