[ruby/rubygems] Treat nil deserialized config as empty

ruby/rubygems@368fc29ce1

Author: hsbt

lib/bundler/settings.rb

@@ -476,7 +476,7 @@ def load_config(config_file)
       SharedHelpers.filesystem_access(config_file, :read) do |file|
         valid_file = file.exist? && !file.size.zero?
         return {} unless valid_file
-        serializer_class.load(file.read).inject({}) do |config, (k, v)|
+        (serializer_class.load(file.read) || {}).inject({}) do |config, (k, v)|
           k = k.dup
           k << "/" if /https?:/i.match?(k) && !k.end_with?("/", "__#{FALLBACK_TIMEOUT_URI_OPTION.upcase}")
           k.gsub!(".", "__")