Fix automatic inheritance.

It is now possible to subclass any nested class or module in a class inheriting from Report (like CostQuery) at the same time keeping it optional. That way no code has to be copy-pasted from the engine and a hook system is largely uneccessary. No alias_method_chain needed, as it works essentially like having Module#prepend with the notable exception of being able to run two seperate reporting subclasses in the same process. This is necessary for the Usage Reporing (creating reports both on logins and courses, for example) and might come in handy if we want to create reports on issues or other entities in Redmine.

Finn: #3416, Cockpit: #18043.
Signed-off-by: Konstantin Haase <konstantin.mailinglists@googlemail.com>

app/models/report/inherited_namespace.rb

@@ -1,6 +1,5 @@
 module Report::InheritedNamespace
   NESTED_NAMESPACES = %w[Validation Filter GroupBy Result]
-  
 
   def self.activate
     Report.extend self
@@ -8,10 +7,8 @@ module Report::InheritedNamespace
   end
 
   def const_missing(name, *)
-    puts "const_missing called on #{self.name}"
     super
   rescue NameError => error
-    raise error unless respond_to? :superclass and superclass != self
     load_constant name, error
   end
 
@@ -27,9 +24,11 @@ module Report::InheritedNamespace
   
   def propagate(klass)
     klass.extend Report::InheritedNamespace
+    return unless klass < Report
     NESTED_NAMESPACES.each do |name|
       if file = ActiveSupport::Dependencies.search_for_file("#{klass.name}::#{name}".underscore)
         require_or_load file
+        klass.const_get(name).extend Report::InheritedNamespace
       else
         const_missing name
       end
@@ -37,14 +36,13 @@ module Report::InheritedNamespace
   end
 
   def load_constant(name, error = nil)
-    puts "#{self.name} #{name}"
-    zuper = superclass.const_get(name)
+    zuper = (Class === self ? superclass : ancestors.second).const_get(name)
     case zuper
     when Class  then const_set name, Class.new(zuper).extend(Report::InheritedNamespace)
     when Module then const_set name, Module.new { include zuper }.extend(Report::InheritedNamespace)
     else const_set name, zuper
     end
-  rescue NameError, ArgumentError
+  rescue NameError, ArgumentError => new_error
     raise error
   end
 end