Make sure that custom field format cannot be changed.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@10624 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/custom_field.rb

@@ -53,6 +53,11 @@ class CustomField < ActiveRecord::Base
 
   CUSTOM_FIELDS_NAMES = CUSTOM_FIELDS_TABS.collect{|v| v[:name]}
 
+  def field_format=(arg)
+    # cannot change format of a saved custom field
+    super if new_record?
+  end
+
   def set_searchable
     # make sure these fields are not searchable
     self.searchable = false if %w(int float date bool).include?(field_format)

test/unit/custom_field_test.rb

@@ -57,6 +57,12 @@ class CustomFieldTest < ActiveSupport::TestCase
     assert field.valid?
   end
 
+  def test_should_not_change_field_format_of_existing_custom_field
+    field = CustomField.find(1)
+    field.field_format = 'int'
+    assert_equal 'list', field.field_format
+  end
+
   def test_possible_values_should_accept_an_array
     field = CustomField.new
     field.possible_values = ["One value", ""]