Index: test/unit/issue_test.rb
===================================================================
--- test/unit/issue_test.rb	(revision 1075)
+++ test/unit/issue_test.rb	(working copy)
@@ -18,7 +18,7 @@
 require File.dirname(__FILE__) + '/../test_helper'
 
 class IssueTest < Test::Unit::TestCase
-  fixtures :projects, :users, :members, :trackers, :projects_trackers, :issue_statuses, :issue_categories, :enumerations, :issues, :custom_fields, :custom_values, :time_entries
+  fixtures :projects, :users, :members, :trackers, :projects_trackers, :issue_statuses, :issue_categories, :enumerations, :issues, :custom_fields, :custom_values, :time_entries, :versions
 
   def test_category_based_assignment
     issue = Issue.create(:project_id => 1, :tracker_id => 1, :author_id => 3, :status_id => 1, :priority => Enumeration.get_values('IPRI').first, :subject => 'Assignment test', :description => 'Assignment test', :category_id => 1)
@@ -70,4 +70,13 @@
     # Make sure time entries were move to the target project
     assert_equal 2, issue.time_entries.first.project_id
   end
+  
+  def test_inherit_version_due_date_if_necessary
+    issue = Issue.find(1)
+    version = Version.find(1)
+    issue.fixed_version = version
+    issue.due_date = nil
+    assert issue.save
+    assert_equal issue.due_date, version.due_date
+  end
 end
Index: app/models/issue.rb
===================================================================
--- app/models/issue.rb	(revision 1075)
+++ app/models/issue.rb	(working copy)
@@ -137,6 +137,13 @@
       }      
       @current_journal.save
     end
+    
+    # If the issue has a fixed version and the issue's due date is empty
+    # then fill it in with the due date of the fixed version
+    if (version = self.fixed_version) && self.due_date.blank?
+      self.due_date = version.due_date
+    end
+    
     # Save the issue even if the journal is not saved (because empty)
     true
   end