Doing a resync from mainline 8633:10895. There was one simple to resolve conflict on app/models/node.rb. Also moving the migrations for API0.6 to new sequence numbers since there was some new migrations added to mainline, where the migration numbers would conflict if not moved.

db/migrate/019_key_constraints.rb

@@ -0,0 +1,50 @@
+class KeyConstraints < ActiveRecord::Migration
+  def self.up
+    # Primary keys
+    add_primary_key :current_node_tags, [:id, :k]
+    add_primary_key :current_way_tags, [:id, :k]
+    add_primary_key :current_relation_tags, [:id, :k]
+
+    add_primary_key :node_tags, [:id, :version, :k]
+    add_primary_key :way_tags, [:id, :version, :k]
+    add_primary_key :relation_tags, [:id, :version, :k]
+
+    add_primary_key :nodes, [:id, :version]
+
+    # Remove indexes superseded by primary keys
+    remove_index :current_way_tags, :name => :current_way_tags_id_idx
+    remove_index :current_relation_tags, :name => :current_relation_tags_id_idx
+
+    remove_index :way_tags, :name => :way_tags_id_version_idx
+    remove_index :relation_tags, :name => :relation_tags_id_version_idx
+
+    remove_index :nodes, :name => :nodes_uid_idx
+
+    # Foreign keys (between ways, way_tags, way_nodes, etc.)
+    add_foreign_key :current_node_tags, [:id], :current_nodes
+    add_foreign_key :node_tags, [:id, :version], :nodes
+
+    add_foreign_key :current_way_tags, [:id], :current_ways
+    add_foreign_key :current_way_nodes, [:id], :current_ways
+    add_foreign_key :way_tags, [:id, :version], :ways
+    add_foreign_key :way_nodes, [:id, :version], :ways
+
+    add_foreign_key :current_relation_tags, [:id], :current_relations
+    add_foreign_key :current_relation_members, [:id], :current_relations
+    add_foreign_key :relation_tags, [:id, :version], :relations
+    add_foreign_key :relation_members, [:id, :version], :relations
+
+    # Foreign keys (between different types of primitives)
+    add_foreign_key :current_way_nodes, [:node_id], :current_nodes, [:id]
+
+    # FIXME: We don't have foreign keys for relation members since the id
+    # might point to a different table depending on the `type' column.
+    # We'd probably need different current_relation_member_nodes,
+    # current_relation_member_ways and current_relation_member_relations
+    # tables for this to work cleanly.
+  end
+
+  def self.down
+    raise IrreversibleMigration.new
+  end
+end