Adds status transition validation

app/models/type.rb

@@ -102,8 +102,20 @@ class Type < ActiveRecord::Base
     PlanningElementTypeColor.all
   end
 
+  def is_valid_transition?(status_id_a, status_id_b, roles)
+    transition_exists?(status_id_a, status_id_b, roles.collect(&:id))
+  end
+
 private
+
   def check_integrity
     raise "Can't delete type" if WorkPackage.find(:first, :conditions => ["type_id=?", self.id])
   end
+
+  def transition_exists?(status_id_a, status_id_b, role_ids)
+    !workflows.where(old_status_id: status_id_a,
+                     new_status_id: status_id_b,
+                     role_id: role_ids)
+              .empty?
+  end
 end

app/models/work_package/validations.rb

@@ -46,6 +46,8 @@ module WorkPackage::Validations
 
     validate :validate_milestone_constraint
     validate :validate_parent_constraint
+
+    validate :validate_status_transition
   end
 
   def validate_start_date_before_soonest_start_date
@@ -84,4 +86,22 @@ module WorkPackage::Validations
       errors.add :parent_id, :cannot_be_milestone if parent.is_milestone?
     end
   end
+
+  def validate_status_transition
+    if status_changed? && !status_transition_exists?
+      errors.add :status_id, :status_transition_invalid
+    end
+  end
+
+  private
+
+  def status_changed?
+    self.status_id_was != 0 && self.status_id_changed?
+  end
+
+  def status_transition_exists?
+    roles = User.current.roles_for_project(self.project)
+
+    self.type.is_valid_transition?(self.status_id_was, self.status_id, roles)
+  end
 end

config/locales/de.yml

@@ -219,6 +219,8 @@ de:
               cannot_be_in_another_project: "darf nicht in einem anderen Projekt sein"
               not_a_valid_parent: "ist ungültig"
               does_not_exist: "existiert nicht"
+            status_id:
+              status_transition_invalid: "es existiert kein valider Übergang vom alten zum neuen Status"
         project_association:
           identical_projects: "kann nicht von einem Projekt auf sich selbst erstellt werden"
           project_association_not_allowed: "erlaubt keine Projekt-Abhängigkeiten"

config/locales/en.yml

@@ -220,6 +220,8 @@ en:
               cannot_be_in_another_project: "cannot be in another project"
               not_a_valid_parent: "is invaild"
               does_not_exist: "does not exist"
+            status_id:
+              status_transition_invalid: "no valid transition exists from old to new status"
         user:
           attributes:
             password: