* ext/psych/lib/psych/visitors/to_ruby.rb: revive hashes with ivars

* ext/psych/lib/psych/visitors/yaml_tree.rb: dump hashes with ivars.
  Fixes github.com/psych/issues/43

* test/psych/test_hash.rb: test for change

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49188 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 51 insertions, 8 deletions

diff --git a/ext/psych/lib/psych/visitors/to_ruby.rb b/ext/psych/lib/psych/visitors/to_ruby.rb
index e696ebd4ff..adf38a21e8 100644
--- a/ext/psych/lib/psych/visitors/to_ruby.rb
+++ b/ext/psych/lib/psych/visitors/to_ruby.rb
@@ -261,6 +261,20 @@ module Psych
           end
           set
 
+        when /^!ruby\/hash-with-ivars(?::(.*))?$/
+          hash = $1 ? resolve_class($1).new : {}
+          o.children.each_slice(2) do |key, value|
+            case key.value
+            when 'elements'
+              revive_hash hash, value
+            when 'ivars'
+              value.children.each_slice(2) do |k,v|
+                hash.instance_variable_set accept(k), accept(v)
+              end
+            end
+          end
+          hash
+
         when /^!map:(.*)$/, /^!ruby\/hash:(.*)$/
           revive_hash register(o, resolve_class($1).new), o
 
diff --git a/ext/psych/lib/psych/visitors/yaml_tree.rb b/ext/psych/lib/psych/visitors/yaml_tree.rb
index 989e1f0de5..bedf9d35b2 100644
--- a/ext/psych/lib/psych/visitors/yaml_tree.rb
+++ b/ext/psych/lib/psych/visitors/yaml_tree.rb
@@ -367,17 +367,46 @@ module Psych
       end
 
       def visit_Hash o
-        tag      = o.class == ::Hash ? nil : "!ruby/hash:#{o.class}"
-        implicit = !tag
+        ivars    = o.instance_variables
 
-        register(o, @emitter.start_mapping(nil, tag, implicit, Psych::Nodes::Mapping::BLOCK))
+        if ivars.any?
+          tag = "!ruby/hash-with-ivars"
+          tag << ":#{o.class}" unless o.class == ::Hash
 
-        o.each do |k,v|
-          accept k
-          accept v
-        end
+          register(o, @emitter.start_mapping(nil, tag, false, Psych::Nodes::Mapping::BLOCK))
 
-        @emitter.end_mapping
+          @emitter.scalar 'elements', nil, nil, true, false, Nodes::Scalar::ANY
+
+          @emitter.start_mapping nil, nil, true, Nodes::Mapping::BLOCK
+          o.each do |k,v|
+            accept k
+            accept v
+          end
+          @emitter.end_mapping
+
+          @emitter.scalar 'ivars', nil, nil, true, false, Nodes::Scalar::ANY
+
+          @emitter.start_mapping nil, nil, true, Nodes::Mapping::BLOCK
+          o.instance_variables.each do |ivar|
+            accept ivar
+            accept o.instance_variable_get ivar
+          end
+          @emitter.end_mapping
+
+          @emitter.end_mapping
+        else
+          tag      = o.class == ::Hash ? nil : "!ruby/hash:#{o.class}"
+          implicit = !tag
+
+          register(o, @emitter.start_mapping(nil, tag, implicit, Psych::Nodes::Mapping::BLOCK))
+
+          o.each do |k,v|
+            accept k
+            accept v
+          end
+
+          @emitter.end_mapping
+        end
       end
 
       def visit_Psych_Set o