Merge branch 'v1.8'

25 files changed, 121 insertions, 552 deletions

diff --git a/.travis.yml b/.travis.yml
index 22cb59f..70db3f8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,16 +11,17 @@ rvm:
   - 2.1
   - 2.2.1
   - 2.2.2
+  - 2.2.3
   - 2.2
+  - 2.3.0
   - ree
-  - rbx-2
-  - jruby-18mode
-  - jruby-19mode
   - ruby-head
 matrix:
+  include:
+    - rvm: jruby
+      env: JRUBY_OPTS="--2.0"
   allow_failures:
     - rvm: rbx-2
     - rvm: ruby-head
 script: "bundle exec rake"
-
 sudo: false
diff --git a/CHANGES b/CHANGES
index 8ffecf7..cb0019e 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,12 @@
+2015-09-11 (1.8.5)
+  * There were still some mentions of dual GPL licensing in the source, but JSON
+    has just the Ruby license that itself includes an explicit dual-licensing
+    clause that allows covered software to be distributed under the terms of
+    the Simplified BSD License instead for all ruby versions >= 1.9.3. This is
+    however a GPL compatible license according to the Free Software Foundation.
+    I changed these mentions to be consistent with the Ruby license setting in
+    the gemspec files which were already correct now.
+---------- (1.8.4) Skipped.
 2015-06-01 (1.8.3)
   * Fix potential memory leak, thx to nobu.
 2015-01-08 (1.8.2)
diff --git a/COPYING b/COPYING
deleted file mode 100644
index c3a2126..0000000
--- a/COPYING
+++ /dev/null
@@ -1,58 +0,0 @@
-Ruby is copyrighted free software by Yukihiro Matsumoto <matz@netlab.co.jp>.
-You can redistribute it and/or modify it under either the terms of the GPL
-(see GPL file), or the conditions below:
-
-  1. You may make and give away verbatim copies of the source form of the
-     software without restriction, provided that you duplicate all of the
-     original copyright notices and associated disclaimers.
-
-  2. You may modify your copy of the software in any way, provided that
-     you do at least ONE of the following:
-
-       a) place your modifications in the Public Domain or otherwise
-          make them Freely Available, such as by posting said
-	  modifications to Usenet or an equivalent medium, or by allowing
-	  the author to include your modifications in the software.
-
-       b) use the modified software only within your corporation or
-          organization.
-
-       c) rename any non-standard executables so the names do not conflict
-	  with standard executables, which must also be provided.
-
-       d) make other distribution arrangements with the author.
-
-  3. You may distribute the software in object code or executable
-     form, provided that you do at least ONE of the following:
-
-       a) distribute the executables and library files of the software,
-	  together with instructions (in the manual page or equivalent)
-	  on where to get the original distribution.
-
-       b) accompany the distribution with the machine-readable source of
-	  the software.
-
-       c) give non-standard executables non-standard names, with
-          instructions on where to get the original software distribution.
-
-       d) make other distribution arrangements with the author.
-
-  4. You may modify and include the part of the software into any other
-     software (possibly commercial).  But some files in the distribution
-     are not written by the author, so that they are not under this terms.
-
-     They are gc.c(partly), utils.c(partly), regex.[ch], st.[ch] and some
-     files under the ./missing directory.  See each file for the copying
-     condition.
-
-  5. The scripts and library files supplied as input to or produced as 
-     output from the software do not automatically fall under the
-     copyright of the software, but belong to whomever generated them, 
-     and may be sold commercially, and may be aggregated with this
-     software.
-
-  6. THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
-     IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
-     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-     PURPOSE.
-
diff --git a/COPYING-json-jruby b/COPYING-json-jruby
deleted file mode 100644
index 137a3da..0000000
--- a/COPYING-json-jruby
+++ /dev/null
@@ -1,57 +0,0 @@
-JSON-JRuby is copyrighted free software by Daniel Luz <mernen at gmail dot com>,
-and is a derivative work of Florian Frank's json library <flori at ping dot de>.
-You can redistribute it and/or modify it under either the terms of the GPL
-version 2 (see the file GPL), or the conditions below:
-
-  1. You may make and give away verbatim copies of the source form of the
-     software without restriction, provided that you duplicate all of the
-     original copyright notices and associated disclaimers.
-
-  2. You may modify your copy of the software in any way, provided that
-     you do at least ONE of the following:
-
-       a) place your modifications in the Public Domain or otherwise
-          make them Freely Available, such as by posting said
-	  modifications to Usenet or an equivalent medium, or by allowing
-	  the author to include your modifications in the software.
-
-       b) use the modified software only within your corporation or
-          organization.
-
-       c) give non-standard binaries non-standard names, with
-          instructions on where to get the original software distribution.
-
-       d) make other distribution arrangements with the author.
-
-  3. You may distribute the software in object code or binary form,
-     provided that you do at least ONE of the following:
-
-       a) distribute the binaries and library files of the software,
-	  together with instructions (in the manual page or equivalent)
-	  on where to get the original distribution.
-
-       b) accompany the distribution with the machine-readable source of
-	  the software.
-
-       c) give non-standard binaries non-standard names, with
-          instructions on where to get the original software distribution.
-
-       d) make other distribution arrangements with the author.
-
-  4. You may modify and include the part of the software into any other
-     software (possibly commercial).  But some files in the distribution
-     are not written by the author, so that they are not under these terms.
-
-     For the list of those files and their copying conditions, see the
-     file LEGAL.
-
-  5. The scripts and library files supplied as input to or produced as 
-     output from the software do not automatically fall under the
-     copyright of the software, but belong to whomever generated them, 
-     and may be sold commercially, and may be aggregated with this
-     software.
-
-  6. THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
-     IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
-     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-     PURPOSE.
diff --git a/GPL b/GPL
deleted file mode 100644
index db2fc45..0000000
--- a/GPL
+++ /dev/null
@@ -1,340 +0,0 @@
-                    GNU GENERAL PUBLIC LICENSE
-                       Version 2, June 1991
-
- Copyright (C) 1989, 1991 Free Software Foundation, Inc.
-                       59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-                            Preamble
-
-  The licenses for most software are designed to take away your
-freedom to share and change it.  By contrast, the GNU General Public
-License is intended to guarantee your freedom to share and change free
-software--to make sure the software is free for all its users.  This
-General Public License applies to most of the Free Software
-Foundation's software and to any other program whose authors commit to
-using it.  (Some other Free Software Foundation software is covered by
-the GNU Library General Public License instead.)  You can apply it to
-your programs, too.
-
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
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-  We protect your rights with two steps: (1) copyright the software, and
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-
-                    GNU GENERAL PUBLIC LICENSE
-   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
-
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-a notice placed by the copyright holder saying it may be distributed
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-the term "modification".)  Each licensee is addressed as "you".
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-You may charge a fee for the physical act of transferring a copy, and
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-address new problems or concerns.
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-later version", you have the option of following the terms and conditions
-either of that version or of any later version published by the Free
-Software Foundation.  If the Program does not specify a version number of
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-  10. If you wish to incorporate parts of the Program into other free
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-                     END OF TERMS AND CONDITIONS
-
-            How to Apply These Terms to Your New Programs
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-    it under the terms of the GNU General Public License as published by
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-    (at your option) any later version.
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-    but WITHOUT ANY WARRANTY; without even the implied warranty of
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-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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-Also add information on how to contact you by electronic and paper mail.
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-    This is free software, and you are welcome to redistribute it
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-
-The hypothetical commands `show w' and `show c' should show the appropriate
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-
-  <signature of Ty Coon>, 1 April 1989
-  Ty Coon, President of Vice
-
-This General Public License does not permit incorporating your program into
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diff --git a/README.rdoc b/README.md
index ebb8b82..7fc6c14 100644
--- a/README.rdoc
+++ b/README.md
@@ -1,6 +1,6 @@
-= JSON implementation for Ruby {<img src="https://secure.travis-ci.org/flori/json.png" />}[http://travis-ci.org/flori/json]
+# JSON implementation for Ruby {<img src="https://secure.travis-ci.org/flori/json.png" />}[http://travis-ci.org/flori/json]
 
-== Description
+## Description
 
 This is a implementation of the JSON specification according to RFC 4627
 http://www.ietf.org/rfc/rfc4627.txt . Starting from version 1.0.0 on there
@@ -11,17 +11,17 @@ will be two variants available:
 * The quite a bit faster native extension variant, which is in parts
   implemented in C or Java and comes with its own unicode conversion
   functions and a parser generated by the ragel state machine compiler
-  http://www.cs.queensu.ca/~thurston/ragel .
+  http://www.complang.org/ragel/ .
 
 Both variants of the JSON generator generate UTF-8 character sequences by
-default. If an :ascii_only option with a true value is given, they escape all
+default. If an :ascii\_only option with a true value is given, they escape all
 non-ASCII and control characters with \uXXXX escape sequences, and support
 UTF-16 surrogate pairs in order to be able to generate the whole range of
 unicode code points.
 
 All strings, that are to be encoded as JSON strings, should be UTF-8 byte
 sequences on the Ruby side. To encode raw binary strings, that aren't UTF-8
-encoded, please use the to_json_raw_object method of String (which produces
+encoded, please use the to\_json\_raw\_object method of String (which produces
 an object, that contains a byte array) and decode the result on the receiving
 endpoint.
 
@@ -32,7 +32,7 @@ String#encoding set. If a document string has ASCII-8BIT as an encoding the
 parser attempts to figure out which of the UTF encodings from above it is and
 trys to parse it.
 
-== Installation
+## Installation
 
 It's recommended to use the extension variant of JSON, because it's faster than
 the pure ruby variant. If you cannot build it on your system, you can settle
@@ -63,29 +63,18 @@ with:
 
   # gem install json_pure
 
-== Compiling the extensions yourself
-
-If you want to build the extensions yourself you need rake:
-
-  You can get it from rubyforge:
-    http://rubyforge.org/projects/rake
-
-  or just type
-
-  # gem install rake
-
-  for the installation via rubygems.
+## Compiling the extensions yourself
 
 If you want to create the parser.c file from its parser.rl file or draw nice
-graphviz images of the state machines, you need ragel from: http://www.cs.queensu.ca/~thurston/ragel
-
+graphviz images of the state machines, you need ragel from:
+http://www.complang.org/ragel/
 
-== Usage
+## Usage
 
 To use JSON you can
   require 'json'
 to load the installed variant (either the extension 'json' or the pure
-variant 'json_pure'). If you have installed the extension variant, you can
+variant 'json\_pure'). If you have installed the extension variant, you can
 pick either the extension variant or the pure variant by typing
   require 'json/ext'
 or
@@ -98,8 +87,8 @@ Now you can parse a JSON document into a ruby data structure by calling
 If you want to generate a JSON document from a ruby data structure call
   JSON.generate(data)
 
-You can also use the pretty_generate method (which formats the output more
-verbosely and nicely) or fast_generate (which doesn't do any of the security
+You can also use the pretty\_generate method (which formats the output more
+verbosely and nicely) or fast\_generate (which doesn't do any of the security
 checks generate performs, e. g. nesting deepness checks).
 
 To create a valid JSON document you have to make sure, that the output is
@@ -134,7 +123,7 @@ To get the best compatibility to rails' JSON implementation, you can
 Both of the additions attempt to require 'json' (like above) first, if it has
 not been required yet.
 
-== More Examples
+## More Examples
 
 To create a JSON document from a ruby data structure, you can call
 JSON.generate like that:
@@ -151,11 +140,11 @@ JSON.parse on it:
 Note, that the range from the original data structure is a simple
 string now. The reason for this is, that JSON doesn't support ranges
 or arbitrary classes. In this case the json library falls back to call
-Object#to_json, which is the same as #to_s.to_json.
+Object#to\_json, which is the same as #to\_s.to\_json.
 
 It's possible to add JSON support serialization to arbitrary classes by
-simply implementing a more specialized version of the #to_json method, that
-should return a JSON object (a hash converted to JSON with #to_json) like
+simply implementing a more specialized version of the #to\_json method, that
+should return a JSON object (a hash converted to JSON with #to\_json) like
 this (don't forget the *a for all the arguments):
 
  class Range
@@ -167,15 +156,15 @@ this (don't forget the *a for all the arguments):
    end
  end
 
-The hash key 'json_class' is the class, that will be asked to deserialise the
+The hash key 'json\_class' is the class, that will be asked to deserialise the
 JSON representation later. In this case it's 'Range', but any namespace of
 the form 'A::B' or '::A::B' will do. All other keys are arbitrary and can be
 used to store the necessary data to configure the object to be deserialised.
 
-If a the key 'json_class' is found in a JSON object, the JSON parser checks
-if the given class responds to the json_create class method. If so, it is
+If a the key 'json\_class' is found in a JSON object, the JSON parser checks
+if the given class responds to the json\_create class method. If so, it is
 called with the JSON object converted to a Ruby hash. So a range can
-be deserialised by implementing Range.json_create like this:
+be deserialised by implementing Range.json\_create like this:
 
  class Range
    def self.json_create(o)
@@ -193,7 +182,7 @@ Now it possible to serialise/deserialise ranges as well:
 JSON.generate always creates the shortest possible string representation of a
 ruby data structure in one line. This is good for data storage or network
 protocols, but not so good for humans to read. Fortunately there's also
-JSON.pretty_generate (or JSON.pretty_generate) that creates a more readable
+JSON.pretty\_generate (or JSON.pretty\_generate) that creates a more readable
 output:
 
  puts JSON.pretty_generate([1, 2, {"a"=>3.141}, false, true, nil, 4..10])
@@ -217,14 +206,14 @@ output:
  ]
 
 There are also the methods Kernel#j for generate, and Kernel#jj for
-pretty_generate output to the console, that work analogous to Core Ruby's p and
+pretty\_generate output to the console, that work analogous to Core Ruby's p and
 the pp library's pp methods.
 
 The script tools/server.rb contains a small example if you want to test, how
 receiving a JSON object from a webrick server in your browser with the
 javasript prototype library http://www.prototypejs.org works.
 
-== Speed Comparisons
+## Speed Comparisons
 
 I have created some benchmark results (see the benchmarks/data-p4-3Ghz
 subdir of the package) for the JSON-parser to estimate the speed up in the C
@@ -303,10 +292,10 @@ speed:
 
 In the table above 1-3 are JSON::Ext::Generator methods. 4, 6, and 7 are
 JSON::Pure::Generator methods and 5 is the Rails JSON generator. It is now a
-bit faster than the generator_safe and generator_pretty methods of the pure
+bit faster than the generator\_safe and generator\_pretty methods of the pure
 variant but slower than the others.
 
-To achieve the fastest JSON document output, you can use the fast_generate
+To achieve the fastest JSON document output, you can use the fast\_generate
 method. Beware, that this will disable the checking for circular Ruby data
 structures, which may cause JSON to go into an infinite loop.
 
@@ -337,21 +326,19 @@ Here are the median comparisons for completeness' sake:
             calls/sec (  time) ->    speed  covers
             secs/call
 
-== Author
+## Author
 
 Florian Frank <mailto:flori@ping.de>
 
-== License
+## License
 
-Ruby License, see the COPYING file included in the source distribution. The
-Ruby License includes the GNU General Public License (GPL), Version 2, so see
-the file GPL as well.
+Ruby License, see https://www.ruby-lang.org/en/about/license.txt.
 
-== Download
+## Download
 
 The latest version of this library can be downloaded at
 
-* http://rubyforge.org/frs?group_id=953
+* https://rubygems.org/gems/json
 
 Online Documentation should be located at
 
diff --git a/Rakefile b/Rakefile
index bef1f39..3b99c60 100644
--- a/Rakefile
+++ b/Rakefile
@@ -83,11 +83,12 @@ if defined?(Gem) and defined?(Gem::PackageTask)
     s.files = PKG_FILES
 
     s.require_path = 'lib'
+    s.add_development_dependency 'rake'
 
-    s.extra_rdoc_files << 'README.rdoc'
+    s.extra_rdoc_files << 'README.md'
     s.rdoc_options <<
-      '--title' <<  'JSON implemention for ruby' << '--main' << 'README.rdoc'
-    s.test_files.concat Dir['./tests/*_test.rb']
+      '--title' <<  'JSON implemention for ruby' << '--main' << 'README.md'
+    s.test_files.concat Dir['./tests/test_*.rb']
 
     s.author = "Florian Frank"
     s.email = "flori@ping.de"
@@ -119,10 +120,10 @@ if defined?(Gem) and defined?(Gem::PackageTask)
 
     s.require_path = 'lib'
 
-    s.extra_rdoc_files << 'README.rdoc'
+    s.extra_rdoc_files << 'README.md'
     s.rdoc_options <<
-      '--title' <<  'JSON implemention for Ruby' << '--main' << 'README.rdoc'
-    s.test_files.concat Dir['./tests/*_test.rb']
+      '--title' <<  'JSON implemention for Ruby' << '--main' << 'README.md'
+    s.test_files.concat Dir['./tests/test_*.rb']
 
     s.author = "Florian Frank"
     s.email = "flori@ping.de"
@@ -336,11 +337,6 @@ else
     t.options = '-v'
   end
 
-  desc "Create RDOC documentation"
-  task :doc => [ :version, EXT_PARSER_SRC ] do
-    sh "rdoc -o doc -t '#{PKG_TITLE}' -m README.rdoc README.rdoc lib/json.rb #{FileList['lib/json/**/*.rb']} #{EXT_PARSER_SRC} #{EXT_GENERATOR_SRC}"
-  end
-
   desc "Generate parser with ragel"
   task :ragel => EXT_PARSER_SRC
 
diff --git a/ext/json/ext/generator/generator.c b/ext/json/ext/generator/generator.c
index 0a3e920..393e29c 100644
--- a/ext/json/ext/generator/generator.c
+++ b/ext/json/ext/generator/generator.c
@@ -871,7 +871,7 @@ static void generate_json(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *s
     } else {
         tmp = rb_funcall(obj, i_to_s, 0);
         Check_Type(tmp, T_STRING);
-        generate_json(buffer, Vstate, state, tmp);
+        generate_json_string(buffer, Vstate, state, tmp);
     }
 }
 
diff --git a/java/src/json/ext/ByteListTranscoder.java b/java/src/json/ext/ByteListTranscoder.java
index ed9e54b..6f6ab66 100644
--- a/java/src/json/ext/ByteListTranscoder.java
+++ b/java/src/json/ext/ByteListTranscoder.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/Generator.java b/java/src/json/ext/Generator.java
index ecceb27..bb3a394 100644
--- a/java/src/json/ext/Generator.java
+++ b/java/src/json/ext/Generator.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
@@ -428,11 +427,14 @@ public final class Generator {
         new Handler<IRubyObject>() {
             @Override
             RubyString generateNew(Session session, IRubyObject object) {
-                IRubyObject result =
-                    object.callMethod(session.getContext(), "to_json",
-                          new IRubyObject[] {session.getState()});
-                if (result instanceof RubyString) return (RubyString)result;
-                throw session.getRuntime().newTypeError("to_json must return a String");
+                if (object.respondsTo("to_json")) {
+                    IRubyObject result = object.callMethod(session.getContext(), "to_json",
+                              new IRubyObject[] {session.getState()});
+                    if (result instanceof RubyString) return (RubyString)result;
+                    throw session.getRuntime().newTypeError("to_json must return a String");
+                } else {
+                    return OBJECT_HANDLER.generateNew(session, object);
+                }
             }
 
             @Override
diff --git a/java/src/json/ext/GeneratorMethods.java b/java/src/json/ext/GeneratorMethods.java
index 637b579..bde7a18 100644
--- a/java/src/json/ext/GeneratorMethods.java
+++ b/java/src/json/ext/GeneratorMethods.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/GeneratorService.java b/java/src/json/ext/GeneratorService.java
index ed33639..e665ad1 100644
--- a/java/src/json/ext/GeneratorService.java
+++ b/java/src/json/ext/GeneratorService.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/GeneratorState.java b/java/src/json/ext/GeneratorState.java
index db4f3f5..11d98d0 100644
--- a/java/src/json/ext/GeneratorState.java
+++ b/java/src/json/ext/GeneratorState.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/OptionsReader.java b/java/src/json/ext/OptionsReader.java
index 8212503..9bb6e64 100644
--- a/java/src/json/ext/OptionsReader.java
+++ b/java/src/json/ext/OptionsReader.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/Parser.java b/java/src/json/ext/Parser.java
index 37423f5..5458fb1 100644
--- a/java/src/json/ext/Parser.java
+++ b/java/src/json/ext/Parser.java
@@ -3,8 +3,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/Parser.rl b/java/src/json/ext/Parser.rl
index 6d65963..d43c74f 100644
--- a/java/src/json/ext/Parser.rl
+++ b/java/src/json/ext/Parser.rl
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/ParserService.java b/java/src/json/ext/ParserService.java
index dde8834..b6015f9 100644
--- a/java/src/json/ext/ParserService.java
+++ b/java/src/json/ext/ParserService.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/RuntimeInfo.java b/java/src/json/ext/RuntimeInfo.java
index 5de5740..ceaca5b 100644
--- a/java/src/json/ext/RuntimeInfo.java
+++ b/java/src/json/ext/RuntimeInfo.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/StringDecoder.java b/java/src/json/ext/StringDecoder.java
index 6023113..76cf183 100644
--- a/java/src/json/ext/StringDecoder.java
+++ b/java/src/json/ext/StringDecoder.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/java/src/json/ext/StringEncoder.java b/java/src/json/ext/StringEncoder.java
index 57bd19b..9d40dd3 100644
--- a/java/src/json/ext/StringEncoder.java
+++ b/java/src/json/ext/StringEncoder.java
@@ -1,3 +1,8 @@
+/*
+ * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
+ *
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
+ */
 package json.ext;
 
 import org.jruby.exceptions.RaiseException;
diff --git a/java/src/json/ext/Utils.java b/java/src/json/ext/Utils.java
index 44d6a55..ed6f832 100644
--- a/java/src/json/ext/Utils.java
+++ b/java/src/json/ext/Utils.java
@@ -1,8 +1,7 @@
 /*
  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
  *
- * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
- * for details.
+ * Distributed under the Ruby license: https://www.ruby-lang.org/en/about/license.txt
  */
 package json.ext;
 
diff --git a/json.gemspec b/json.gemspec
index 5bd9463..00f0744 100644
--- a/json.gemspec
+++ b/json.gemspec
diff --git a/json_pure.gemspec b/json_pure.gemspec
index 843fe6d..937aae7 100644
--- a/json_pure.gemspec
+++ b/json_pure.gemspec
@@ -8,15 +8,27 @@ Gem::Specification.new do |s|
   s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
   s.require_paths = ["lib"]
   s.authors = ["Florian Frank"]
-  s.date = "2015-06-15"
+  s.date = "2016-02-25"
   s.description = "This is a JSON implementation in pure Ruby."
   s.email = "flori@ping.de"
-  s.extra_rdoc_files = ["README.rdoc"]
-  s.files = ["./tests/json_addition_test.rb", "./tests/json_common_interface_test.rb", "./tests/json_encoding_test.rb", "./tests/json_ext_parser_test.rb", "./tests/json_fixtures_test.rb", "./tests/json_generator_test.rb", "./tests/json_generic_object_test.rb", "./tests/json_parser_test.rb", "./tests/json_string_matching_test.rb", ".gitignore", ".travis.yml", "CHANGES", "COPYING", "COPYING-json-jruby", "GPL", "Gemfile", "README-json-jruby.markdown", "README.rdoc", "Rakefile", "TODO", "VERSION", "data/example.json", "data/index.html", "data/prototype.js", "diagrams/.keep", "ext/json/ext/fbuffer/fbuffer.h", "ext/json/ext/generator/depend", "ext/json/ext/generator/extconf.rb", "ext/json/ext/generator/generator.c", "ext/json/ext/generator/generator.h", "ext/json/ext/parser/depend", "ext/json/ext/parser/extconf.rb", "ext/json/ext/parser/parser.c", "ext/json/ext/parser/parser.h", "ext/json/ext/parser/parser.rl", "ext/json/extconf.rb", "install.rb", "java/src/json/ext/ByteListTranscoder.java", "java/src/json/ext/Generator.java", "java/src/json/ext/GeneratorMethods.java", "java/src/json/ext/GeneratorService.java", "java/src/json/ext/GeneratorState.java", "java/src/json/ext/OptionsReader.java", "java/src/json/ext/Parser.java", "java/src/json/ext/Parser.rl", "java/src/json/ext/ParserService.java", "java/src/json/ext/RuntimeInfo.java", "java/src/json/ext/StringDecoder.java", "java/src/json/ext/StringEncoder.java", "java/src/json/ext/Utils.java", "json-java.gemspec", "json.gemspec", "json_pure.gemspec", "lib/json.rb", "lib/json/add/bigdecimal.rb", "lib/json/add/complex.rb", "lib/json/add/core.rb", "lib/json/add/date.rb", "lib/json/add/date_time.rb", "lib/json/add/exception.rb", "lib/json/add/ostruct.rb", "lib/json/add/range.rb", "lib/json/add/rational.rb", "lib/json/add/regexp.rb", "lib/json/add/struct.rb", "lib/json/add/symbol.rb", "lib/json/add/time.rb", "lib/json/common.rb", "lib/json/ext.rb", "lib/json/ext/.keep", "lib/json/generic_object.rb", "lib/json/pure.rb", "lib/json/pure/generator.rb", "lib/json/pure/parser.rb", "lib/json/version.rb", "tests/fixtures/fail10.json", "tests/fixtures/fail11.json", "tests/fixtures/fail12.json", "tests/fixtures/fail13.json", "tests/fixtures/fail14.json", "tests/fixtures/fail18.json", "tests/fixtures/fail19.json", "tests/fixtures/fail2.json", "tests/fixtures/fail20.json", "tests/fixtures/fail21.json", "tests/fixtures/fail22.json", "tests/fixtures/fail23.json", "tests/fixtures/fail24.json", "tests/fixtures/fail25.json", "tests/fixtures/fail27.json", "tests/fixtures/fail28.json", "tests/fixtures/fail3.json", "tests/fixtures/fail4.json", "tests/fixtures/fail5.json", "tests/fixtures/fail6.json", "tests/fixtures/fail7.json", "tests/fixtures/fail8.json", "tests/fixtures/fail9.json", "tests/fixtures/obsolete_fail1.json", "tests/fixtures/pass1.json", "tests/fixtures/pass15.json", "tests/fixtures/pass16.json", "tests/fixtures/pass17.json", "tests/fixtures/pass2.json", "tests/fixtures/pass26.json", "tests/fixtures/pass3.json", "tests/json_addition_test.rb", "tests/json_common_interface_test.rb", "tests/json_encoding_test.rb", "tests/json_ext_parser_test.rb", "tests/json_fixtures_test.rb", "tests/json_generator_test.rb", "tests/json_generic_object_test.rb", "tests/json_parser_test.rb", "tests/json_string_matching_test.rb", "tests/test_helper.rb", "tools/fuzz.rb", "tools/server.rb"]
+  s.extra_rdoc_files = ["README.md"]
+  s.files = ["./tests/test_helper.rb", ".gitignore", ".travis.yml", "CHANGES", "Gemfile", "README-json-jruby.markdown", "README.md", "Rakefile", "TODO", "VERSION", "data/example.json", "data/index.html", "data/prototype.js", "diagrams/.keep", "ext/json/ext/fbuffer/fbuffer.h", "ext/json/ext/generator/depend", "ext/json/ext/generator/extconf.rb", "ext/json/ext/generator/generator.c", "ext/json/ext/generator/generator.h", "ext/json/ext/parser/depend", "ext/json/ext/parser/extconf.rb", "ext/json/ext/parser/parser.c", "ext/json/ext/parser/parser.h", "ext/json/ext/parser/parser.rl", "ext/json/extconf.rb", "install.rb", "java/src/json/ext/ByteListTranscoder.java", "java/src/json/ext/Generator.java", "java/src/json/ext/GeneratorMethods.java", "java/src/json/ext/GeneratorService.java", "java/src/json/ext/GeneratorState.java", "java/src/json/ext/OptionsReader.java", "java/src/json/ext/Parser.java", "java/src/json/ext/Parser.rl", "java/src/json/ext/ParserService.java", "java/src/json/ext/RuntimeInfo.java", "java/src/json/ext/StringDecoder.java", "java/src/json/ext/StringEncoder.java", "java/src/json/ext/Utils.java", "json-java.gemspec", "json.gemspec", "json_pure.gemspec", "lib/json.rb", "lib/json/add/bigdecimal.rb", "lib/json/add/complex.rb", "lib/json/add/core.rb", "lib/json/add/date.rb", "lib/json/add/date_time.rb", "lib/json/add/exception.rb", "lib/json/add/ostruct.rb", "lib/json/add/range.rb", "lib/json/add/rational.rb", "lib/json/add/regexp.rb", "lib/json/add/struct.rb", "lib/json/add/symbol.rb", "lib/json/add/time.rb", "lib/json/common.rb", "lib/json/ext.rb", "lib/json/ext/.keep", "lib/json/generic_object.rb", "lib/json/pure.rb", "lib/json/pure/generator.rb", "lib/json/pure/parser.rb", "lib/json/version.rb", "tests/fixtures/fail10.json", "tests/fixtures/fail11.json", "tests/fixtures/fail12.json", "tests/fixtures/fail13.json", "tests/fixtures/fail14.json", "tests/fixtures/fail18.json", "tests/fixtures/fail19.json", "tests/fixtures/fail2.json", "tests/fixtures/fail20.json", "tests/fixtures/fail21.json", "tests/fixtures/fail22.json", "tests/fixtures/fail23.json", "tests/fixtures/fail24.json", "tests/fixtures/fail25.json", "tests/fixtures/fail27.json", "tests/fixtures/fail28.json", "tests/fixtures/fail3.json", "tests/fixtures/fail4.json", "tests/fixtures/fail5.json", "tests/fixtures/fail6.json", "tests/fixtures/fail7.json", "tests/fixtures/fail8.json", "tests/fixtures/fail9.json", "tests/fixtures/obsolete_fail1.json", "tests/fixtures/pass1.json", "tests/fixtures/pass15.json", "tests/fixtures/pass16.json", "tests/fixtures/pass17.json", "tests/fixtures/pass2.json", "tests/fixtures/pass26.json", "tests/fixtures/pass3.json", "tests/json_addition_test.rb", "tests/json_common_interface_test.rb", "tests/json_encoding_test.rb", "tests/json_ext_parser_test.rb", "tests/json_fixtures_test.rb", "tests/json_generator_test.rb", "tests/json_generic_object_test.rb", "tests/json_parser_test.rb", "tests/json_string_matching_test.rb", "tests/test_helper.rb", "tools/fuzz.rb", "tools/server.rb"]
   s.homepage = "http://flori.github.com/json"
   s.licenses = ["Ruby"]
-  s.rdoc_options = ["--title", "JSON implemention for ruby", "--main", "README.rdoc"]
-  s.rubygems_version = "2.4.6"
+  s.rdoc_options = ["--title", "JSON implemention for ruby", "--main", "README.md"]
+  s.rubygems_version = "2.5.1"
   s.summary = "JSON Implementation for Ruby"
-  s.test_files = ["./tests/json_addition_test.rb", "./tests/json_common_interface_test.rb", "./tests/json_encoding_test.rb", "./tests/json_ext_parser_test.rb", "./tests/json_fixtures_test.rb", "./tests/json_generator_test.rb", "./tests/json_generic_object_test.rb", "./tests/json_parser_test.rb", "./tests/json_string_matching_test.rb"]
+  s.test_files = ["./tests/test_helper.rb"]
+
+  if s.respond_to? :specification_version then
+    s.specification_version = 4
+
+    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0') then
+      s.add_development_dependency(%q<rake>, [">= 0"])
+    else
+      s.add_dependency(%q<rake>, [">= 0"])
+    end
+  else
+    s.add_dependency(%q<rake>, [">= 0"])
+  end
 end
diff --git a/lib/json/pure/generator.rb b/lib/json/pure/generator.rb
index cb27e04..cc8b0fd 100644
--- a/lib/json/pure/generator.rb
+++ b/lib/json/pure/generator.rb
@@ -357,7 +357,11 @@ module JSON
               result << state.space_before
               result << ':'
               result << state.space
-              result << value.to_json(state)
+              if value.respond_to?(:to_json)
+                result << value.to_json(state)
+              else
+                result << %{"#{String(value)}"}
+              end
               first = false
             }
             depth = state.depth -= 1
@@ -392,7 +396,11 @@ module JSON
             each { |value|
               result << delim unless first
               result << state.indent * depth if indent
-              result << value.to_json(state)
+              if value.respond_to?(:to_json)
+                result << value.to_json(state)
+              else
+                result << %{"#{String(value)}"}
+              end
               first = false
             }
             depth = state.depth -= 1
diff --git a/tests/json_generator_test.rb b/tests/json_generator_test.rb
index 7e487d8..2bb7e15 100644
--- a/tests/json_generator_test.rb
+++ b/tests/json_generator_test.rb
@@ -1,3 +1,7 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+# frozen_string_literal: false
+
 require 'test_helper'
 
 class JSONGeneratorTest < Test::Unit::TestCase
@@ -362,4 +366,15 @@ EOT
     json = '["\\\'"]'
     assert_equal '["\'"]', generate(data)
   end
+
+  def test_string_subclass
+    s = Class.new(String) do
+      def to_s; self; end
+      undef to_json
+    end
+    assert_nothing_raised(SystemStackError) do
+      assert_equal '["foo"]', JSON.generate([s.new('foo')])
+    end
+
+  end
 end