merge revision(s) 32578,33401,33403,33404,33531,33655,33679,33809,33900,33965,34067,34069,34087,34328,34330,34527,34772,34783,34839,34914,34953,34954,35153: [Backport #6212]

	* ext/psych/lib/psych.rb: updating version to match gem
	* ext/psych/psych.gemspec: ditto
	* ext/psych/lib/psych/visitors/to_ruby.rb: fixing deprecation warning

	* ext/psych/lib/psych.rb: define a new BadAlias error class.

	* ext/psych/lib/psych/visitors/to_ruby.rb: raise an exception when
	  deserializing an alias that does not exist.

	* test/psych/test_merge_keys.rb: corresponding test.

	* ext/psych/lib/psych.rb (load, parse): stop parsing or loading after
	  the first document has been parsed.

	* test/psych/test_stream.rb: pertinent tests.

	* ext/psych/lib/psych.rb (parse_stream, load_stream): if a block is
	  given, documents will be yielded to the block as they are parsed.
	  [ruby-core:42404] [Bug #5978]

	* ext/psych/lib/psych/handlers/document_stream.rb: add a handler that
	  yields documents as they are parsed

	* test/psych/test_stream.rb: corresponding tests.

	* ext/psych/lib/psych/core_ext.rb: only extend Kernel if IRB is loaded
	  in order to stop method pollution.

	* ext/psych/lib/psych.rb: default open YAML files with utf8 external
	  encoding. [ruby-core:42967]
	* test/psych/test_tainted.rb: ditto

	* ext/psych/parser.c: prevent a memory leak by protecting calls to
	  handler callbacks.
	* test/psych/test_parser.rb: test to demonstrate leak.

	* ext/psych/parser.c: set parser encoding based on the YAML input
	  rather than user configuration.
	* test/psych/test_encoding.rb: corresponding tests.
	* test/psych/test_parser.rb: ditto
	* test/psych/test_tainted.rb: ditto

	* ext/psych/parser.c: removed external encoding setter, allow parser
	  to be reused.
	* ext/psych/lib/psych/parser.rb: added external encoding setter.
	* test/psych/test_parser.rb: test parser reuse

	* ext/psych/lib/psych/visitors/to_ruby.rb: Added support for loading
	  subclasses of String with ivars
	* ext/psych/lib/psych/visitors/yaml_tree.rb: Added support for dumping
	  subclasses of String with ivars
	* test/psych/test_string.rb: corresponding tests

	* ext/psych/lib/psych/visitors/to_ruby.rb: Added ability to load array
	  subclasses with ivars.
	* ext/psych/lib/psych/visitors/yaml_tree.rb: Added ability to dump
	  array subclasses with ivars.
	* test/psych/test_array.rb: corresponding tests

	* ext/psych/emitter.c: fixing clang warnings. Thanks Joey!

	* ext/psych/lib/psych/visitors/to_ruby.rb: BigDecimals can be restored
	  from YAML.
	* ext/psych/lib/psych/visitors/yaml_tree.rb: BigDecimals can be dumped
	  to YAML.
	* test/psych/test_numeric.rb: tests for BigDecimal serialization

	* ext/psych/lib/psych/scalar_scanner.rb: Strings that look like dates
	  should be treated as strings and not dates.

	* test/psych/test_scalar_scanner.rb: corresponding tests.

	* ext/psych/lib/psych.rb (module Psych): parse and load methods take
	  an optional file name that is used when raising Psych::SyntaxError
	  exceptions
	* ext/psych/lib/psych/syntax_error.rb (module Psych): allow nil file
	  names and handle nil file names in the exception message
	* test/psych/test_exception.rb (module Psych): Tests for changes.

	* ext/psych/parser.c (parse): parse method can take an option file
	  name for use in exception messages.
	* test/psych/test_parser.rb: corresponding tests.

	* ext/psych/lib/psych.rb: remove autoload from psych
	* ext/psych/lib/psych/json.rb: ditto

	* ext/psych/lib/psych/tree_builder.rb: dump complex numbers,
	  rationals, etc with reference ids.
	* ext/psych/lib/psych/visitors/yaml_tree.rb: ditto
	* ext/psych/lib/psych/visitors/to_ruby.rb: loading complex numbers,
	  rationals, etc with reference ids.
	* test/psych/test_object_references.rb: corresponding tests

	* ext/psych/lib/psych/scalar_scanner.rb: make sure strings that look
	  like base 60 numbers are serialized as quoted strings.
	* test/psych/test_string.rb: test for change.

	* ext/psych/parser.c: remove unused variable.

	* ext/psych/lib/psych/syntax_error.rb: Add file, line, offset, and
	  message attributes during parse failure.
	* ext/psych/parser.c: Update parser to raise exception with correct
	  values.
	* test/psych/test_exception.rb: corresponding tests.

	* ext/psych/parser.c (parse): Use context_mark for indicating error
	  line and column.

	* ext/psych/lib/psych/scalar_scanner.rb: use normal begin / rescue
	  since postfix rescue cannot receive the exception class. Thanks
	  nagachika!

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@35165 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

12 files changed, 506 insertions, 123 deletions

diff --git a/ext/psych/emitter.c b/ext/psych/emitter.c
index a85fa45ef5..15fdcfe75b 100644
--- a/ext/psych/emitter.c
+++ b/ext/psych/emitter.c
@@ -351,7 +351,7 @@ static VALUE start_mapping(
 	    (yaml_char_t *)(NIL_P(anchor) ? NULL : StringValuePtr(anchor)),
 	    (yaml_char_t *)(NIL_P(tag) ? NULL : StringValuePtr(tag)),
 	    implicit ? 1 : 0,
-	    (yaml_sequence_style_t)NUM2INT(style)
+	    (yaml_mapping_style_t)NUM2INT(style)
 	    );
 
     emit(emitter, &event);
diff --git a/ext/psych/lib/psych.rb b/ext/psych/lib/psych.rb
index f9052f92a4..82578204fb 100644
--- a/ext/psych/lib/psych.rb
+++ b/ext/psych/lib/psych.rb
@@ -10,7 +10,10 @@ require 'psych/set'
 require 'psych/coder'
 require 'psych/core_ext'
 require 'psych/deprecated'
-require 'psych/json'
+require 'psych/stream'
+require 'psych/json/tree_builder'
+require 'psych/json/stream'
+require 'psych/handlers/document_stream'
 
 ###
 # = Overview
@@ -90,7 +93,7 @@ require 'psych/json'
 
 module Psych
   # The version is Psych you're using
-  VERSION         = '1.2.2'
+  VERSION         = '1.3.1'
 
   # The version of libyaml Psych is using
   LIBYAML_VERSION = Psych.libyaml_version.join '.'
@@ -98,39 +101,66 @@ module Psych
   class Exception < RuntimeError
   end
 
-  autoload :Stream, 'psych/stream'
+  class BadAlias < Exception
+  end
 
   ###
   # Load +yaml+ in to a Ruby data structure.  If multiple documents are
   # provided, the object contained in the first document will be returned.
+  # +filename+ will be used in the exception message if any exception is raised
+  # while parsing.
+  #
+  # Raises a Psych::SyntaxError when a YAML syntax error is detected.
   #
   # Example:
   #
-  #   Psych.load("--- a")           # => 'a'
-  #   Psych.load("---\n - a\n - b") # => ['a', 'b']
-  def self.load yaml
-    result = parse(yaml)
+  #   Psych.load("--- a")             # => 'a'
+  #   Psych.load("---\n - a\n - b")   # => ['a', 'b']
+  #
+  #   begin
+  #     Psych.load("--- `", "file.txt")
+  #   rescue Psych::SyntaxError => ex
+  #     ex.file    # => 'file.txt'
+  #     ex.message # => "(foo.txt): found character that cannot start any token"
+  #   end
+  def self.load yaml, filename = nil
+    result = parse(yaml, filename)
     result ? result.to_ruby : result
   end
 
   ###
   # Parse a YAML string in +yaml+.  Returns the first object of a YAML AST.
+  # +filename+ is used in the exception message if a Psych::SyntaxError is
+  # raised.
+  #
+  # Raises a Psych::SyntaxError when a YAML syntax error is detected.
   #
   # Example:
   #
   #   Psych.parse("---\n - a\n - b") # => #<Psych::Nodes::Sequence:0x00>
   #
+  #   begin
+  #     Psych.parse("--- `", "file.txt")
+  #   rescue Psych::SyntaxError => ex
+  #     ex.file    # => 'file.txt'
+  #     ex.message # => "(foo.txt): found character that cannot start any token"
+  #   end
+  #
   # See Psych::Nodes for more information about YAML AST.
-  def self.parse yaml
-    children = parse_stream(yaml).children
-    children.empty? ? false : children.first.children.first
+  def self.parse yaml, filename = nil
+    parse_stream(yaml, filename) do |node|
+      return node
+    end
+    false
   end
 
   ###
   # Parse a file at +filename+. Returns the YAML AST.
+  #
+  # Raises a Psych::SyntaxError when a YAML syntax error is detected.
   def self.parse_file filename
-    File.open filename do |f|
-      parse f
+    File.open filename, 'r:bom|utf-8' do |f|
+      parse f, filename
     end
   end
 
@@ -143,16 +173,39 @@ module Psych
   ###
   # Parse a YAML string in +yaml+.  Returns the full AST for the YAML document.
   # This method can handle multiple YAML documents contained in +yaml+.
+  # +filename+ is used in the exception message if a Psych::SyntaxError is
+  # raised.
+  #
+  # If a block is given, a Psych::Nodes::Document node will be yielded to the
+  # block as it's being parsed.
+  #
+  # Raises a Psych::SyntaxError when a YAML syntax error is detected.
   #
   # Example:
   #
   #   Psych.parse_stream("---\n - a\n - b") # => #<Psych::Nodes::Stream:0x00>
   #
+  #   Psych.parse_stream("--- a\n--- b") do |node|
+  #     node # => #<Psych::Nodes::Document:0x00>
+  #   end
+  #
+  #   begin
+  #     Psych.parse_stream("--- `", "file.txt")
+  #   rescue Psych::SyntaxError => ex
+  #     ex.file    # => 'file.txt'
+  #     ex.message # => "(foo.txt): found character that cannot start any token"
+  #   end
+  #
   # See Psych::Nodes for more information about YAML AST.
-  def self.parse_stream yaml
-    parser = self.parser
-    parser.parse yaml
-    parser.handler.root
+  def self.parse_stream yaml, filename = nil, &block
+    if block_given?
+      parser = Psych::Parser.new(Handlers::DocumentStream.new(&block))
+      parser.parse yaml, filename
+    else
+      parser = self.parser
+      parser.parse yaml, filename
+      parser.handler.root
+    end
   end
 
   ###
@@ -214,19 +267,34 @@ module Psych
 
   ###
   # Load multiple documents given in +yaml+.  Returns the parsed documents
-  # as a list.  For example:
+  # as a list.  If a block is given, each document will be converted to ruby
+  # and passed to the block during parsing
+  #
+  # Example:
   #
   #   Psych.load_stream("--- foo\n...\n--- bar\n...") # => ['foo', 'bar']
   #
-  def self.load_stream yaml
-    parse_stream(yaml).children.map { |child| child.to_ruby }
+  #   list = []
+  #   Psych.load_stream("--- foo\n...\n--- bar\n...") do |ruby|
+  #     list << ruby
+  #   end
+  #   list # => ['foo', 'bar']
+  #
+  def self.load_stream yaml, filename = nil
+    if block_given?
+      parse_stream(yaml, filename) do |node|
+        yield node.to_ruby
+      end
+    else
+      parse_stream(yaml, filename).children.map { |child| child.to_ruby }
+    end
   end
 
   ###
   # Load the document contained in +filename+.  Returns the yaml contained in
   # +filename+ as a ruby object
   def self.load_file filename
-    File.open(filename) { |f| self.load f }
+    File.open(filename, 'r:bom|utf-8') { |f| self.load f, filename }
   end
 
   # :stopdoc:
diff --git a/ext/psych/lib/psych/core_ext.rb b/ext/psych/lib/psych/core_ext.rb
index 2ad75e1661..4a04c2d128 100644
--- a/ext/psych/lib/psych/core_ext.rb
+++ b/ext/psych/lib/psych/core_ext.rb
@@ -30,6 +30,7 @@ class Module
   alias :yaml_as :psych_yaml_as
 end
 
+if defined?(::IRB)
 module Kernel
   def psych_y *objects
     puts Psych.dump_stream(*objects)
@@ -38,3 +39,4 @@ module Kernel
   alias y psych_y
   private :y
 end
+end
diff --git a/ext/psych/lib/psych/handlers/document_stream.rb b/ext/psych/lib/psych/handlers/document_stream.rb
new file mode 100644
index 0000000000..e429993c1c
--- /dev/null
+++ b/ext/psych/lib/psych/handlers/document_stream.rb
@@ -0,0 +1,22 @@
+require 'psych/tree_builder'
+
+module Psych
+  module Handlers
+    class DocumentStream < Psych::TreeBuilder # :nodoc:
+      def initialize &block
+        super
+        @block = block
+      end
+
+      def start_document version, tag_directives, implicit
+        n = Nodes::Document.new version, tag_directives, implicit
+        push n
+      end
+
+      def end_document implicit_end = !streaming?
+        @last.implicit_end = implicit_end
+        @block.call pop
+      end
+    end
+  end
+end
diff --git a/ext/psych/lib/psych/json.rb b/ext/psych/lib/psych/json.rb
deleted file mode 100644
index 412ab2708b..0000000000
--- a/ext/psych/lib/psych/json.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-module Psych
-  module JSON
-    autoload :TreeBuilder, 'psych/json/tree_builder'
-    autoload :Stream, 'psych/json/stream'
-  end
-end
diff --git a/ext/psych/lib/psych/parser.rb b/ext/psych/lib/psych/parser.rb
index 5d75605d49..84085f1fb0 100644
--- a/ext/psych/lib/psych/parser.rb
+++ b/ext/psych/lib/psych/parser.rb
@@ -36,12 +36,16 @@ module Psych
     # The handler on which events will be called
     attr_accessor :handler
 
+    # Set the encoding for this parser to +encoding+
+    attr_writer :external_encoding
+
     ###
     # Creates a new Psych::Parser instance with +handler+.  YAML events will
     # be called on +handler+.  See Psych::Parser for more details.
 
     def initialize handler = Handler.new
       @handler = handler
+      @external_encoding = ANY
     end
   end
 end
diff --git a/ext/psych/lib/psych/scalar_scanner.rb b/ext/psych/lib/psych/scalar_scanner.rb
index 3e8acbb21c..fa2d385a63 100644
--- a/ext/psych/lib/psych/scalar_scanner.rb
+++ b/ext/psych/lib/psych/scalar_scanner.rb
@@ -46,9 +46,13 @@ module Psych
         end
       when TIME
         parse_time string
-      when /^\d{4}-\d{1,2}-\d{1,2}$/
+      when /^\d{4}-(?:1[012]|0\d|\d)-(?:[12]\d|3[01]|0\d|\d)$/
         require 'date'
-        Date.strptime(string, '%Y-%m-%d')
+        begin
+          Date.strptime(string, '%Y-%m-%d')
+        rescue ArgumentError
+          string
+        end
       when /^\.inf$/i
         1 / 0.0
       when /^-\.inf$/i
@@ -61,7 +65,7 @@ module Psych
         else
           string.sub(/^:/, '').to_sym
         end
-      when /^[-+]?[1-9][0-9_]*(:[0-5]?[0-9])+$/
+      when /^[-+]?[0-9][0-9_]*(:[0-5]?[0-9])+$/
         i = 0
         string.split(':').each_with_index do |n,e|
           i += (n.to_i * 60 ** (e - 2).abs)
@@ -74,13 +78,19 @@ module Psych
         end
         i
       when FLOAT
-        return Float(string.gsub(/[,_]/, '')) rescue ArgumentError
+        begin
+          return Float(string.gsub(/[,_]/, ''))
+        rescue ArgumentError
+        end
 
         @string_cache[string] = true
         string
       else
         if string.count('.') < 2
-          return Integer(string.gsub(/[,_]/, '')) rescue ArgumentError
+          begin
+            return Integer(string.gsub(/[,_]/, ''))
+          rescue ArgumentError
+          end
         end
 
         @string_cache[string] = true
diff --git a/ext/psych/lib/psych/syntax_error.rb b/ext/psych/lib/psych/syntax_error.rb
new file mode 100644
index 0000000000..f79743dba4
--- /dev/null
+++ b/ext/psych/lib/psych/syntax_error.rb
@@ -0,0 +1,19 @@
+module Psych
+  class SyntaxError < ::SyntaxError
+    attr_reader :file, :line, :column, :offset, :problem, :context
+
+    def initialize file, line, col, offset, problem, context
+      err      = [problem, context].compact.join ' '
+      filename = file || '<unknown>'
+      message  = "(%s): %s at line %d column %d" % [filename, err, line, col]
+
+      @file    = file
+      @line    = line
+      @column  = col
+      @offset  = offset
+      @problem = problem
+      @context = context
+      super(message)
+    end
+  end
+end
diff --git a/ext/psych/lib/psych/tree_builder.rb b/ext/psych/lib/psych/tree_builder.rb
index 8b4e972314..c8f344787c 100644
--- a/ext/psych/lib/psych/tree_builder.rb
+++ b/ext/psych/lib/psych/tree_builder.rb
@@ -72,7 +72,9 @@ module Psych
     end
 
     def scalar value, anchor, tag, plain, quoted, style
-      @last.children << Nodes::Scalar.new(value,anchor,tag,plain,quoted,style)
+      s = Nodes::Scalar.new(value,anchor,tag,plain,quoted,style)
+      @last.children << s
+      s
     end
 
     def alias anchor
diff --git a/ext/psych/lib/psych/visitors/to_ruby.rb b/ext/psych/lib/psych/visitors/to_ruby.rb
index ca046c5da9..2e082f90b4 100644
--- a/ext/psych/lib/psych/visitors/to_ruby.rb
+++ b/ext/psych/lib/psych/visitors/to_ruby.rb
@@ -31,9 +31,7 @@ module Psych
         result
       end
 
-      def visit_Psych_Nodes_Scalar o
-        @st[o.anchor] = o.value if o.anchor
-
+      def deserialize o
         if klass = Psych.load_tags[o.tag]
           instance = klass.allocate
 
@@ -52,8 +50,16 @@ module Psych
         case o.tag
         when '!binary', 'tag:yaml.org,2002:binary'
           o.value.unpack('m').first
-        when '!str', 'tag:yaml.org,2002:str'
-          o.value
+        when /^!(?:str|ruby\/string)(?::(.*))?/, 'tag:yaml.org,2002:str'
+          klass = resolve_class($1)
+          if klass
+            klass.allocate.replace o.value
+          else
+            o.value
+          end
+        when '!ruby/object:BigDecimal'
+          require 'bigdecimal'
+          BigDecimal._load o.value
         when "!ruby/object:DateTime"
           require 'date'
           @ss.parse_time(o.value).to_datetime
@@ -92,6 +98,11 @@ module Psych
           @ss.tokenize o.value
         end
       end
+      private :deserialize
+
+      def visit_Psych_Nodes_Scalar o
+        register o, deserialize(o)
+      end
 
       def visit_Psych_Nodes_Sequence o
         if klass = Psych.load_tags[o.tag]
@@ -108,15 +119,18 @@ module Psych
 
         case o.tag
         when '!omap', 'tag:yaml.org,2002:omap'
-          map = Psych::Omap.new
-          @st[o.anchor] = map if o.anchor
+          map = register(o, Psych::Omap.new)
           o.children.each { |a|
             map[accept(a.children.first)] = accept a.children.last
           }
           map
+        when /^!(?:seq|ruby\/array):(.*)$/
+          klass = resolve_class($1)
+          list  = register(o, klass.allocate)
+          o.children.each { |c| list.push accept c }
+          list
         else
-          list = []
-          @st[o.anchor] = list if o.anchor
+          list = register(o, [])
           o.children.each { |c| list.push accept c }
           list
         end
@@ -127,16 +141,33 @@ module Psych
         return revive_hash({}, o) unless o.tag
 
         case o.tag
-        when '!str', 'tag:yaml.org,2002:str'
+        when /^!(?:str|ruby\/string)(?::(.*))?/, 'tag:yaml.org,2002:str'
+          klass = resolve_class($1)
           members = Hash[*o.children.map { |c| accept c }]
           string = members.delete 'str'
+
+          if klass
+            string = klass.allocate
+            string.replace string
+          end
+
           init_with(string, members.map { |k,v| [k.to_s.sub(/^@/, ''),v] }, o)
+        when /^!ruby\/array:(.*)$/
+          klass = resolve_class($1)
+          list  = register(o, klass.allocate)
+
+          members = Hash[o.children.map { |c| accept c }.each_slice(2).to_a]
+          list.replace members['internal']
+
+          members['ivars'].each do |ivar, v|
+            list.instance_variable_set ivar, v
+          end
+          list
         when /^!ruby\/struct:?(.*)?$/
           klass = resolve_class($1)
 
           if klass
-            s = klass.allocate
-            @st[o.anchor] = s if o.anchor
+            s = register(o, klass.allocate)
 
             members = {}
             struct_members = s.members.map { |x| x.to_sym }
@@ -158,7 +189,7 @@ module Psych
 
         when '!ruby/range'
           h = Hash[*o.children.map { |c| accept c }]
-          Range.new(h['begin'], h['end'], h['excl'])
+          register o, Range.new(h['begin'], h['end'], h['excl'])
 
         when /^!ruby\/exception:?(.*)?$/
           h = Hash[*o.children.map { |c| accept c }]
@@ -177,11 +208,11 @@ module Psych
 
         when '!ruby/object:Complex'
           h = Hash[*o.children.map { |c| accept c }]
-          Complex(h['real'], h['image'])
+          register o, Complex(h['real'], h['image'])
 
         when '!ruby/object:Rational'
           h = Hash[*o.children.map { |c| accept c }]
-          Rational(h['numerator'], h['denominator'])
+          register o, Rational(h['numerator'], h['denominator'])
 
         when /^!ruby\/object:?(.*)?$/
           name = $1 || 'Object'
@@ -205,10 +236,15 @@ module Psych
       end
 
       def visit_Psych_Nodes_Alias o
-        @st[o.anchor]
+        @st.fetch(o.anchor) { raise BadAlias, "Unknown alias: #{o.anchor}" }
       end
 
       private
+      def register node, object
+        @st[node.anchor] = object if node.anchor
+        object
+      end
+
       def revive_hash hash, o
         @st[o.anchor] = hash if o.anchor
 
@@ -249,7 +285,7 @@ module Psych
           o.init_with c
         elsif o.respond_to?(:yaml_initialize)
           if $VERBOSE
-            "Implementing #{o.class}#yaml_initialize is deprecated, please implement \"init_with(coder)\""
+            warn "Implementing #{o.class}#yaml_initialize is deprecated, please implement \"init_with(coder)\""
           end
           o.yaml_initialize c.tag, c.map
         else
diff --git a/ext/psych/lib/psych/visitors/yaml_tree.rb b/ext/psych/lib/psych/visitors/yaml_tree.rb
index 5a092850c3..80af0466eb 100644
--- a/ext/psych/lib/psych/visitors/yaml_tree.rb
+++ b/ext/psych/lib/psych/visitors/yaml_tree.rb
@@ -159,13 +159,13 @@ module Psych
       end
 
       def visit_Regexp o
-        @emitter.scalar o.inspect, nil, '!ruby/regexp', false, false, Nodes::Scalar::ANY
+        register o, @emitter.scalar(o.inspect, nil, '!ruby/regexp', false, false, Nodes::Scalar::ANY)
       end
 
       def visit_DateTime o
         formatted = format_time o.to_time
         tag = '!ruby/object:DateTime'
-        @emitter.scalar formatted, nil, tag, false, false, Nodes::Scalar::ANY
+        register o, @emitter.scalar(formatted, nil, tag, false, false, Nodes::Scalar::ANY)
       end
 
       def visit_Time o
@@ -174,7 +174,7 @@ module Psych
       end
 
       def visit_Rational o
-        @emitter.start_mapping(nil, '!ruby/object:Rational', false, Nodes::Mapping::BLOCK)
+        register o, @emitter.start_mapping(nil, '!ruby/object:Rational', false, Nodes::Mapping::BLOCK)
 
         [
           'denominator', o.denominator.to_s,
@@ -187,7 +187,7 @@ module Psych
       end
 
       def visit_Complex o
-        @emitter.start_mapping(nil, '!ruby/object:Complex', false, Nodes::Mapping::BLOCK)
+        register o, @emitter.start_mapping(nil, '!ruby/object:Complex', false, Nodes::Mapping::BLOCK)
 
         ['real', o.real.to_s, 'image', o.imag.to_s].each do |m|
           @emitter.scalar m, nil, nil, true, false, Nodes::Scalar::ANY
@@ -214,6 +214,10 @@ module Psych
         end
       end
 
+      def visit_BigDecimal o
+        @emitter.scalar o._dump, nil, '!ruby/object:BigDecimal', false, false, Nodes::Scalar::ANY
+      end
+
       def binary? string
         string.encoding == Encoding::ASCII_8BIT ||
           string.index("\x00") ||
@@ -241,9 +245,15 @@ module Psych
         ivars = find_ivars o
 
         if ivars.empty?
+          unless o.class == ::String
+            tag = "!ruby/string:#{o.class}"
+          end
           @emitter.scalar str, nil, tag, plain, quote, style
         else
-          @emitter.start_mapping nil, '!str', false, Nodes::Mapping::BLOCK
+          maptag = '!ruby/string'
+          maptag << ":#{o.class}" unless o.class == ::String
+
+          @emitter.start_mapping nil, maptag, false, Nodes::Mapping::BLOCK
           @emitter.scalar 'str', nil, nil, true, false, Nodes::Scalar::ANY
           @emitter.scalar str, nil, tag, plain, quote, style
 
@@ -255,16 +265,16 @@ module Psych
 
       def visit_Module o
         raise TypeError, "can't dump anonymous module: #{o}" unless o.name
-        @emitter.scalar o.name, nil, '!ruby/module', false, false, Nodes::Scalar::SINGLE_QUOTED
+        register o, @emitter.scalar(o.name, nil, '!ruby/module', false, false, Nodes::Scalar::SINGLE_QUOTED)
       end
 
       def visit_Class o
         raise TypeError, "can't dump anonymous class: #{o}" unless o.name
-        @emitter.scalar o.name, nil, '!ruby/class', false, false, Nodes::Scalar::SINGLE_QUOTED
+        register o, @emitter.scalar(o.name, nil, '!ruby/class', false, false, Nodes::Scalar::SINGLE_QUOTED)
       end
 
       def visit_Range o
-        @emitter.start_mapping nil, '!ruby/range', false, Nodes::Mapping::BLOCK
+        register o, @emitter.start_mapping(nil, '!ruby/range', false, Nodes::Mapping::BLOCK)
         ['begin', o.begin, 'end', o.end, 'excl', o.exclude_end?].each do |m|
           accept m
         end
@@ -297,9 +307,13 @@ module Psych
       end
 
       def visit_Array o
-        register o, @emitter.start_sequence(nil, nil, true, Nodes::Sequence::BLOCK)
-        o.each { |c| accept c }
-        @emitter.end_sequence
+        if o.class == ::Array
+          register o, @emitter.start_sequence(nil, nil, true, Nodes::Sequence::BLOCK)
+          o.each { |c| accept c }
+          @emitter.end_sequence
+        else
+          visit_array_subclass o
+        end
       end
 
       def visit_NilClass o
@@ -311,6 +325,39 @@ module Psych
       end
 
       private
+      def visit_array_subclass o
+        tag = "!ruby/array:#{o.class}"
+        if o.instance_variables.empty?
+          node = @emitter.start_sequence(nil, tag, false, Nodes::Sequence::BLOCK)
+          register o, node
+          o.each { |c| accept c }
+          @emitter.end_sequence
+        else
+          node = @emitter.start_mapping(nil, tag, false, Nodes::Sequence::BLOCK)
+          register o, node
+
+          # Dump the internal list
+          accept 'internal'
+          @emitter.start_sequence(nil, nil, true, Nodes::Sequence::BLOCK)
+          o.each { |c| accept c }
+          @emitter.end_sequence
+
+          # Dump the ivars
+          accept 'ivars'
+          @emitter.start_mapping(nil, nil, true, Nodes::Sequence::BLOCK)
+          o.instance_variables.each do |ivar|
+            accept ivar
+            accept o.instance_variable_get ivar
+          end
+          @emitter.end_mapping
+
+          @emitter.end_mapping
+        end
+      end
+
+      def dump_list o
+      end
+
       # '%:z' was no defined until 1.9.3
       if RUBY_VERSION < '1.9.3'
         def format_time time
diff --git a/ext/psych/parser.c b/ext/psych/parser.c
index e68768f562..9808c6b60e 100644
--- a/ext/psych/parser.c
+++ b/ext/psych/parser.c
@@ -59,6 +59,163 @@ static VALUE allocate(VALUE klass)
     return Data_Wrap_Struct(klass, 0, dealloc, parser);
 }
 
+static VALUE make_exception(yaml_parser_t * parser, VALUE path)
+{
+    size_t line, column;
+
+    line = parser->context_mark.line + 1;
+    column = parser->context_mark.column + 1;
+
+    return rb_funcall(ePsychSyntaxError, rb_intern("new"), 6,
+	    path,
+	    INT2NUM(line),
+	    INT2NUM(column),
+	    INT2NUM(parser->problem_offset),
+	    parser->problem ? rb_usascii_str_new2(parser->problem) : Qnil,
+	    parser->context ? rb_usascii_str_new2(parser->context) : Qnil);
+}
+
+#ifdef HAVE_RUBY_ENCODING_H
+static VALUE transcode_string(VALUE src, int * parser_encoding)
+{
+    int utf8    = rb_utf8_encindex();
+    int utf16le = rb_enc_find_index("UTF16_LE");
+    int utf16be = rb_enc_find_index("UTF16_BE");
+    int source_encoding = rb_enc_get_index(src);
+
+    if (source_encoding == utf8) {
+	*parser_encoding = YAML_UTF8_ENCODING;
+	return src;
+    }
+
+    if (source_encoding == utf16le) {
+	*parser_encoding = YAML_UTF16LE_ENCODING;
+	return src;
+    }
+
+    if (source_encoding == utf16be) {
+	*parser_encoding = YAML_UTF16BE_ENCODING;
+	return src;
+    }
+
+    src = rb_str_export_to_enc(src, rb_utf8_encoding());
+    RB_GC_GUARD(src);
+
+    *parser_encoding = YAML_UTF8_ENCODING;
+    return src;
+}
+
+static VALUE transcode_io(VALUE src, int * parser_encoding)
+{
+    VALUE io_external_encoding;
+    int io_external_enc_index;
+
+    io_external_encoding = rb_funcall(src, rb_intern("external_encoding"), 0);
+
+    /* if no encoding is returned, assume ascii8bit. */
+    if (NIL_P(io_external_encoding)) {
+	io_external_enc_index = rb_ascii8bit_encindex();
+    } else {
+	io_external_enc_index = rb_to_encoding_index(io_external_encoding);
+    }
+
+    /* Treat US-ASCII as utf_8 */
+    if (io_external_enc_index == rb_usascii_encindex()) {
+	*parser_encoding = YAML_UTF8_ENCODING;
+	return src;
+    }
+
+    if (io_external_enc_index == rb_utf8_encindex()) {
+	*parser_encoding = YAML_UTF8_ENCODING;
+	return src;
+    }
+
+    if (io_external_enc_index == rb_enc_find_index("UTF-16LE")) {
+	*parser_encoding = YAML_UTF16LE_ENCODING;
+	return src;
+    }
+
+    if (io_external_enc_index == rb_enc_find_index("UTF-16BE")) {
+	*parser_encoding = YAML_UTF16BE_ENCODING;
+	return src;
+    }
+
+    /* Just guess on ASCII-8BIT */
+    if (io_external_enc_index == rb_ascii8bit_encindex()) {
+	*parser_encoding = YAML_ANY_ENCODING;
+	return src;
+    }
+
+    rb_raise(rb_eArgError, "YAML file must be UTF-8, UTF-16LE, or UTF-16BE, not %s",
+	    rb_enc_name(rb_enc_from_index(io_external_enc_index)));
+
+    return Qnil;
+}
+
+#endif
+
+static VALUE protected_start_stream(VALUE pointer)
+{
+    VALUE *args = (VALUE *)pointer;
+    return rb_funcall(args[0], id_start_stream, 1, args[1]);
+}
+
+static VALUE protected_start_document(VALUE pointer)
+{
+    VALUE *args = (VALUE *)pointer;
+    return rb_funcall3(args[0], id_start_document, 3, args + 1);
+}
+
+static VALUE protected_end_document(VALUE pointer)
+{
+    VALUE *args = (VALUE *)pointer;
+    return rb_funcall(args[0], id_end_document, 1, args[1]);
+}
+
+static VALUE protected_alias(VALUE pointer)
+{
+    VALUE *args = (VALUE *)pointer;
+    return rb_funcall(args[0], id_alias, 1, args[1]);
+}
+
+static VALUE protected_scalar(VALUE pointer)
+{
+    VALUE *args = (VALUE *)pointer;
+    return rb_funcall3(args[0], id_scalar, 6, args + 1);
+}
+
+static VALUE protected_start_sequence(VALUE pointer)
+{
+    VALUE *args = (VALUE *)pointer;
+    return rb_funcall3(args[0], id_start_sequence, 4, args + 1);
+}
+
+static VALUE protected_end_sequence(VALUE handler)
+{
+    return rb_funcall(handler, id_end_sequence, 0);
+}
+
+static VALUE protected_start_mapping(VALUE pointer)
+{
+    VALUE *args = (VALUE *)pointer;
+    return rb_funcall3(args[0], id_start_mapping, 4, args + 1);
+}
+
+static VALUE protected_end_mapping(VALUE handler)
+{
+    return rb_funcall(handler, id_end_mapping, 0);
+}
+
+static VALUE protected_empty(VALUE handler)
+{
+    return rb_funcall(handler, id_empty, 0);
+}
+
+static VALUE protected_end_stream(VALUE handler)
+{
+    return rb_funcall(handler, id_end_stream, 0);
+}
+
 /*
  * call-seq:
  *    parser.parse(yaml)
@@ -68,27 +225,48 @@ static VALUE allocate(VALUE klass)
  *
  * See Psych::Parser and Psych::Parser#handler
  */
-static VALUE parse(VALUE self, VALUE yaml)
+static VALUE parse(int argc, VALUE *argv, VALUE self)
 {
+    VALUE yaml, path;
     yaml_parser_t * parser;
     yaml_event_t event;
     int done = 0;
     int tainted = 0;
+    int state = 0;
+    int parser_encoding = YAML_ANY_ENCODING;
 #ifdef HAVE_RUBY_ENCODING_H
     int encoding = rb_utf8_encindex();
     rb_encoding * internal_enc = rb_default_internal_encoding();
 #endif
     VALUE handler = rb_iv_get(self, "@handler");
 
+    if (rb_scan_args(argc, argv, "11", &yaml, &path) == 1) {
+	if(rb_respond_to(yaml, id_path))
+	    path = rb_funcall(yaml, id_path, 0);
+	else
+	    path = rb_str_new2("<unknown>");
+    }
+
     Data_Get_Struct(self, yaml_parser_t, parser);
 
+    yaml_parser_delete(parser);
+    yaml_parser_initialize(parser);
+
     if (OBJ_TAINTED(yaml)) tainted = 1;
 
-    if(rb_respond_to(yaml, id_read)) {
+    if (rb_respond_to(yaml, id_read)) {
+#ifdef HAVE_RUBY_ENCODING_H
+	yaml = transcode_io(yaml, &parser_encoding);
+	yaml_parser_set_encoding(parser, parser_encoding);
+#endif
 	yaml_parser_set_input(parser, io_reader, (void *)yaml);
 	if (RTEST(rb_obj_is_kind_of(yaml, rb_cIO))) tainted = 1;
     } else {
 	StringValue(yaml);
+#ifdef HAVE_RUBY_ENCODING_H
+	yaml = transcode_string(yaml, &parser_encoding);
+	yaml_parser_set_encoding(parser, parser_encoding);
+#endif
 	yaml_parser_set_input_string(
 		parser,
 		(const unsigned char *)RSTRING_PTR(yaml),
@@ -98,32 +276,28 @@ static VALUE parse(VALUE self, VALUE yaml)
 
     while(!done) {
 	if(!yaml_parser_parse(parser, &event)) {
-	    VALUE path;
-	    size_t line   = parser->mark.line;
-	    size_t column = parser->mark.column;
-
-	    if(rb_respond_to(yaml, id_path))
-		path = rb_funcall(yaml, id_path, 0);
-	    else
-		path = rb_str_new2("<unknown>");
+	    VALUE exception;
 
+	    exception = make_exception(parser, path);
 	    yaml_parser_delete(parser);
 	    yaml_parser_initialize(parser);
 
-	    rb_raise(ePsychSyntaxError, "(%s): couldn't parse YAML at line %d column %d",
-		    StringValuePtr(path),
-		    (int)line, (int)column);
+	    rb_exc_raise(exception);
 	}
 
 	switch(event.type) {
-	  case YAML_STREAM_START_EVENT:
-
-	    rb_funcall(handler, id_start_stream, 1,
-		       INT2NUM((long)event.data.stream_start.encoding)
-		);
-	    break;
+	    case YAML_STREAM_START_EVENT:
+	      {
+		  VALUE args[2];
+
+		  args[0] = handler;
+		  args[1] = INT2NUM((long)event.data.stream_start.encoding);
+		  rb_protect(protected_start_stream, (VALUE)args, &state);
+	      }
+	      break;
 	  case YAML_DOCUMENT_START_EVENT:
 	    {
+		VALUE args[4];
 		/* Get a list of tag directives (if any) */
 		VALUE tag_directives = rb_ary_new();
 		/* Grab the document version */
@@ -161,19 +335,25 @@ static VALUE parse(VALUE self, VALUE yaml)
 			rb_ary_push(tag_directives, rb_ary_new3((long)2, handle, prefix));
 		    }
 		}
-		rb_funcall(handler, id_start_document, 3,
-			   version, tag_directives,
-			   event.data.document_start.implicit == 1 ? Qtrue : Qfalse
-		    );
+		args[0] = handler;
+		args[1] = version;
+		args[2] = tag_directives;
+		args[3] = event.data.document_start.implicit == 1 ? Qtrue : Qfalse;
+		rb_protect(protected_start_document, (VALUE)args, &state);
 	    }
 	    break;
 	  case YAML_DOCUMENT_END_EVENT:
-	    rb_funcall(handler, id_end_document, 1,
-		       event.data.document_end.implicit == 1 ? Qtrue : Qfalse
-		);
+	    {
+		VALUE args[2];
+
+		args[0] = handler;
+		args[1] = event.data.document_end.implicit == 1 ? Qtrue : Qfalse;
+		rb_protect(protected_end_document, (VALUE)args, &state);
+	    }
 	    break;
 	  case YAML_ALIAS_EVENT:
 	    {
+		VALUE args[2];
 		VALUE alias = Qnil;
 		if(event.data.alias.anchor) {
 		    alias = rb_str_new2((const char *)event.data.alias.anchor);
@@ -183,11 +363,14 @@ static VALUE parse(VALUE self, VALUE yaml)
 #endif
 		}
 
-		rb_funcall(handler, id_alias, 1, alias);
+		args[0] = handler;
+		args[1] = alias;
+		rb_protect(protected_alias, (VALUE)args, &state);
 	    }
 	    break;
 	  case YAML_SCALAR_EVENT:
 	    {
+		VALUE args[7];
 		VALUE anchor = Qnil;
 		VALUE tag = Qnil;
 		VALUE plain_implicit, quoted_implicit, style;
@@ -225,12 +408,19 @@ static VALUE parse(VALUE self, VALUE yaml)
 
 		style = INT2NUM((long)event.data.scalar.style);
 
-		rb_funcall(handler, id_scalar, 6,
-			   val, anchor, tag, plain_implicit, quoted_implicit, style);
+		args[0] = handler;
+		args[1] = val;
+		args[2] = anchor;
+		args[3] = tag;
+		args[4] = plain_implicit;
+		args[5] = quoted_implicit;
+		args[6] = style;
+		rb_protect(protected_scalar, (VALUE)args, &state);
 	    }
 	    break;
 	  case YAML_SEQUENCE_START_EVENT:
 	    {
+		VALUE args[5];
 		VALUE anchor = Qnil;
 		VALUE tag = Qnil;
 		VALUE implicit, style;
@@ -256,15 +446,21 @@ static VALUE parse(VALUE self, VALUE yaml)
 
 		style = INT2NUM((long)event.data.sequence_start.style);
 
-		rb_funcall(handler, id_start_sequence, 4,
-			   anchor, tag, implicit, style);
+		args[0] = handler;
+		args[1] = anchor;
+		args[2] = tag;
+		args[3] = implicit;
+		args[4] = style;
+
+		rb_protect(protected_start_sequence, (VALUE)args, &state);
 	    }
 	    break;
 	  case YAML_SEQUENCE_END_EVENT:
-	    rb_funcall(handler, id_end_sequence, 0);
+	    rb_protect(protected_end_sequence, handler, &state);
 	    break;
 	  case YAML_MAPPING_START_EVENT:
 	    {
+		VALUE args[5];
 		VALUE anchor = Qnil;
 		VALUE tag = Qnil;
 		VALUE implicit, style;
@@ -289,22 +485,28 @@ static VALUE parse(VALUE self, VALUE yaml)
 
 		style = INT2NUM((long)event.data.mapping_start.style);
 
-		rb_funcall(handler, id_start_mapping, 4,
-			   anchor, tag, implicit, style);
+		args[0] = handler;
+		args[1] = anchor;
+		args[2] = tag;
+		args[3] = implicit;
+		args[4] = style;
+
+		rb_protect(protected_start_mapping, (VALUE)args, &state);
 	    }
 	    break;
 	  case YAML_MAPPING_END_EVENT:
-	    rb_funcall(handler, id_end_mapping, 0);
+	    rb_protect(protected_end_mapping, handler, &state);
 	    break;
 	  case YAML_NO_EVENT:
-	    rb_funcall(handler, id_empty, 0);
+	    rb_protect(protected_empty, handler, &state);
 	    break;
 	  case YAML_STREAM_END_EVENT:
-	    rb_funcall(handler, id_end_stream, 0);
+	    rb_protect(protected_end_stream, handler, &state);
 	    done = 1;
 	    break;
 	}
 	yaml_event_delete(&event);
+	if (state) rb_jump_tag(state);
     }
 
     return self;
@@ -312,29 +514,6 @@ static VALUE parse(VALUE self, VALUE yaml)
 
 /*
  * call-seq:
- *    parser.external_encoding=(encoding)
- *
- * Set the encoding for this parser to +encoding+
- */
-static VALUE set_external_encoding(VALUE self, VALUE encoding)
-{
-    yaml_parser_t * parser;
-    VALUE exception;
-
-    Data_Get_Struct(self, yaml_parser_t, parser);
-
-    if(parser->encoding) {
-	exception = rb_const_get_at(mPsych, rb_intern("Exception"));
-	rb_raise(exception, "don't set the encoding twice!");
-    }
-
-    yaml_parser_set_encoding(parser, NUM2INT(encoding));
-
-    return encoding;
-}
-
-/*
- * call-seq:
  *    parser.mark # => #<Psych::Parser::Mark>
  *
  * Returns a Psych::Parser::Mark object that contains line, column, and index
@@ -376,11 +555,11 @@ void Init_psych_parser()
     /* UTF-16-BE Encoding with BOM */
     rb_define_const(cPsychParser, "UTF16BE", INT2NUM(YAML_UTF16BE_ENCODING));
 
+    rb_require("psych/syntax_error");
     ePsychSyntaxError = rb_define_class_under(mPsych, "SyntaxError", rb_eSyntaxError);
 
-    rb_define_method(cPsychParser, "parse", parse, 1);
+    rb_define_method(cPsychParser, "parse", parse, -1);
     rb_define_method(cPsychParser, "mark", mark, 0);
-    rb_define_method(cPsychParser, "external_encoding=", set_external_encoding, 1);
 
     id_read           = rb_intern("read");
     id_path           = rb_intern("path");