Convert fallback option to a keyword argument

Converting the optional fallback argument to a keyword argument
fixes a problem that is caused by mixing optional arguments and
optional keyword arguments.

Without this change, a hash as fallback value is not handled
correctly: in Psych.load("", nil, {}) the hash is not interpreted
as the fallback value, and the default value for the fallback
argument is used instead.

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/psych.rb b/lib/psych.rb
index 0f14fe4..03bb4a8 100644
--- a/lib/psych.rb
+++ b/lib/psych.rb
@@ -259,8 +259,8 @@ module Psych
   #   Psych.load("---\n foo: bar")                         # => {"foo"=>"bar"}
   #   Psych.load("---\n foo: bar", symbolize_names: true)  # => {:foo=>"bar"}
   #
-  def self.load yaml, filename = nil, fallback = false, symbolize_names: false
-    result = parse(yaml, filename, fallback)
+  def self.load yaml, filename = nil, fallback: false, symbolize_names: false
+    result = parse(yaml, filename, fallback: fallback)
     result = result.to_ruby if result
     symbolize_names!(result) if symbolize_names
     result
@@ -336,7 +336,7 @@ module Psych
   #   end
   #
   # See Psych::Nodes for more information about YAML AST.
-  def self.parse yaml, filename = nil, fallback = false
+  def self.parse yaml, filename = nil, fallback: false
     parse_stream(yaml, filename) do |node|
       return node
     end
@@ -483,9 +483,9 @@ module Psych
   # Load the document contained in +filename+.  Returns the yaml contained in
   # +filename+ as a Ruby object, or if the file is empty, it returns
   # the specified default return value, which defaults to an empty Hash
-  def self.load_file filename, fallback = false
+  def self.load_file filename, fallback: false
     File.open(filename, 'r:bom|utf-8') { |f|
-      self.load f, filename, FALLBACK.new(fallback)
+      self.load f, filename, fallback: FALLBACK.new(fallback)
     }
   end