better handling of duplicate tags. Extra validation in the tests.

app/models/node.rb

@@ -71,8 +71,8 @@ class Node < ActiveRecord::Base
       doc.find('//osm/node').each do |pt|
         return Node.from_xml_node(pt, create)
       end
-    rescue
+    rescue LibXML::XML::Error => ex
-      return nil
+      raise OSM::APIBadXMLError.new("node", xml, ex.message)
     end
   end
 
@@ -274,7 +274,7 @@ class Node < ActiveRecord::Base
 
     # duplicate tags are now forbidden, so we can't allow values
     # in the hash to be overwritten.
-    raise OSM::APIDuplicateTagsError.new if @tags.include? k
+    raise OSM::APIDuplicateTagsError.new("node", self.id, k) if @tags.include? k
 
     @tags[k] = v
   end

app/models/relation.rb

@@ -209,7 +209,7 @@ class Relation < ActiveRecord::Base
 
     # duplicate tags are now forbidden, so we can't allow values
     # in the hash to be overwritten.
-    raise OSM::APIDuplicateTagsError.new if @tags.include? k
+    raise OSM::APIDuplicateTagsError.new("relation", self.id, k) if @tags.include? k
 
     @tags[k] = v
   end

app/models/way.rb

@@ -34,8 +34,8 @@ class Way < ActiveRecord::Base
       doc.find('//osm/way').each do |pt|
         return Way.from_xml_node(pt, create)
       end
-    rescue
+    rescue LibXML::XML::Error => ex
-      return nil
+      raise OSM::APIBadXMLError.new("relation", xml, ex.message)
     end
   end
 
@@ -182,7 +182,7 @@ class Way < ActiveRecord::Base
 
     # duplicate tags are now forbidden, so we can't allow values
     # in the hash to be overwritten.
-    raise OSM::APIDuplicateTagsError.new if @tags.include? k
+    raise OSM::APIDuplicateTagsError.new("way", self.id, k) if @tags.include? k
 
     @tags[k] = v
   end

test/functional/node_controller_test.rb

@@ -194,7 +194,8 @@ class NodeControllerTest < ActionController::TestCase
     content node_xml
     put :update, :id => current_nodes(:visible_node).id
     assert_response :bad_request, 
-       "adding duplicate tags to a node should fail with 'bad request'"
+      "adding duplicate tags to a node should fail with 'bad request'"
+    assert_equal "Element node/#{current_nodes(:visible_node).id} has duplicate tags with key #{current_node_tags(:t1).k}.", @response.body
   end
 
   # test whether string injection is possible

test/functional/way_controller_test.rb

@@ -219,6 +219,7 @@ class WayControllerTest < ActionController::TestCase
     put :update, :id => current_ways(:visible_way).id
     assert_response :bad_request, 
        "adding a duplicate tag to a way should fail with 'bad request'"
+    assert_equal "Element way/#{current_ways(:visible_way).id} has duplicate tags with key #{current_way_tags(:t1).k}.", @response.body
   end
 
   ##
@@ -243,6 +244,7 @@ class WayControllerTest < ActionController::TestCase
     put :update, :id => current_ways(:visible_way).id
     assert_response :bad_request, 
        "adding new duplicate tags to a way should fail with 'bad request'"
+    assert_equal "Element way/#{current_ways(:visible_way).id} has duplicate tags with key i_am_a_duplicate.", @response.body
   end
 
   ##
@@ -264,6 +266,7 @@ class WayControllerTest < ActionController::TestCase
     put :create
     assert_response :bad_request, 
     "adding new duplicate tags to a way should fail with 'bad request'"
+    assert_equal "Element way/ has duplicate tags with key addr:housenumber.", @response.body
   end
 
   ##