Ticket #10855: drop_table_if_exists.diff

a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -585 +585 @@
-        execute "ALTER TABLE #{name} RENAME TO #{new_name}"
-      end
-
+      # Drops a table from the database.
+      def drop_table(table_name, options = {})
+        args = options[:force] ? " IF EXISTS" : ""
+        execute "DROP TABLE#{args} #{quote_table_name(table_name)}"
+      end
+
-      # Adds a column to a table.
-      def add_column(table_name, column_name, type, options = {})
-        default = options[:default]