fix #1417. We now handle unblocking a todo that is part of a hidden project or context

app/models/todo.rb

@@ -103,7 +103,7 @@ class Todo < ActiveRecord::Base
     end
 
     event :block do
-      transitions :to => :pending, :from => [:active, :deferred]
+      transitions :to => :pending, :from => [:active, :deferred, :project_hidden]
     end
   end
 
@@ -158,6 +158,14 @@ class Todo < ActiveRecord::Base
     return !( uncompleted_predecessors.empty? || state == 'project_hidden' )
   end
 
+  def guard_for_transition_from_deferred_to_pending
+    no_uncompleted_predecessors? && not_part_of_hidden_container?
+  end
+
+  def not_part_of_hidden_container?
+    !( (self.project && self.project.hidden?) || self.context.hidden? )
+  end
+
   # Returns a string with description <context, project>
   def specification
     project_name = self.project.is_a?(NullProject) ? "(none)" : self.project.name
@@ -201,7 +209,7 @@ class Todo < ActiveRecord::Base
   def remove_predecessor(predecessor)
     self.predecessors.delete(predecessor)
     if self.predecessors.empty?
-      self.activate!
+      self.not_part_of_hidden_container? ? self.activate! : self.hide!
     else
       save!
     end

test/unit/todo_test.rb

@@ -239,6 +239,26 @@ class TodoTest < ActiveSupport::TestCase
     assert !@not_completed1.starred?
   end
 
+  def test_hidden_todo_remains_hidden_after_getting_unblokked
+    todo = todos(:call_bill)
+    project=todo.project
+    project.hide!
+
+    assert todo.reload.hidden?, "todo in hidden project should be hidden"
+
+    todo2 = todos(:call_dino_ext)
+    todo.add_predecessor(todo2)
+    todo.block!
+
+    assert todo.pending?, "todo with predecessor should be blocked"
+
+    # cannot activate if part of hidden project
+    assert_raise(AASM::InvalidTransition) { todo.activate! } 
+
+    todo.remove_predecessor(todo2)
+    assert todo.reload.hidden?, "todo should be put back in hidden state"
+  end
+
   def test_todo_specification_handles_null_project
     # @not_completed1 has a project
     todo_desc = @not_completed1.description