Limit the size of ParserError exception messages

Fix: ruby#534

Only include up to 32 bytes of unparseable the source.

Author: byroot

CHANGES.md

@@ -1,6 +1,7 @@
 # Changes
 
 * Numerous performance optimizations in `JSON.generate` and `JSON.dump`.
+* Limit the size of ParserError exception messages, only include up to 32 bytes of the unparseable source.
 * Fix json-pure's `Object#to_json` to accept non state arguments 
 * Fix multiline comment support in `json-pure`.
 * Fix `JSON.parse` to no longer mutate the argument encoding when passed an ASCII-8BIT string.

Rakefile

@@ -258,7 +258,6 @@ else
     task :compile => [ :ragel, EXT_PARSER_DL, EXT_GENERATOR_DL ]
   end
 
-
   desc "Testing library (extension)"
   task :test_ext => [ :set_env_ext, :check_env, :compile, :do_test_ext ]
   task(:set_env_ext) { ENV['JSON'] = 'ext' }