ChangeLog

Next Release 0.16
=====================

Significant changes and bug fixes
---------------------------------
* Introduce constant JSON_C_OBJECT_ADD_CONSTANT_KEY
   as a replacement of JSON_C_OBJECT_KEY_IS_CONSTANT,
   JSON_C_OBJECT_KEY_IS_CONSTANT becoming legacy.
* Direct access to lh_table and lh_entry structure members is deprecated.  
  Use access functions instead, lh_table_head(), lh_entry_next(), etc...
* Drop REFCOUNT_DEBUG code.

***

0.15 (up to commit 870965e, 2020/07/26)
========================================

Deprecated and removed features:
--------------------------------
* Deprecate `array_list_new()` in favor of `array_list_new2()`
* Remove the THIS_FUNCTION_IS_DEPRECATED define.
* Remove config.h.win32

New features
------------
* Add a `JSON_TOKENER_ALLOW_TRAILING_CHARS` flag to allow multiple objects
  to be parsed even when `JSON_TOKENER_STRICT` is set.
* Add `json_object_new_array_ext(int)` and `array_list_new_2(int)` to allow
   arrays to be allocated with the exact size needed, when known.
* Add `json_object_array_shrink()` (and `array_list_shrink()`) and use it in 
   json_tokener to minimize the amount of memory used.
* Add a json_parse binary, for use in testing changes (not installed, but 
   available in the apps directory).

Build changes
-------------
* #639/#621 - Add symbol versions to all exported symbols
* #508/#634 - Always enable -fPIC to allow use of the json-c static library in
   other libraries
* Build both static and shared libraries at the same time.
* #626 - Restore compatibility with cmake 2.8 
* #471 - Always create directories with mode 0755, regardless of umask.
* #606/#604 - Improve support for OSes like AIX and IBM i, as well as for
   MINGW32 and old versions of MSVC
* #451/#617 - Add a DISABLE_THREAD_LOCAL_STORAGE cmake option to disable 
   the use of thread-local storage.

Significant changes and bug fixes
---------------------------------
* Split the internal json_object structure into several sub-types, one for
   each json_type (json_object_object, json_object_string, etc...).
  This improves memory usage and speed, with the benchmark under
   bench/ report 5.8% faster test time and 6%(max RSS)-12%(peak heap)
   less memory usage.
  Memory used just for json_object structures decreased 27%, so use cases
   with fewer arrays and/or strings would benefit more.
* Minimize memory usage in array handling in json_tokener by shrinking
   arrays to the exact number of elements parsed.  On bench/ benchmark:
   9% faster test time, 39%(max RSS)-50%(peak heap) less memory usage.
   Add json_object_array_shrink() and array_list_shrink() functions.
* #616 - Parsing of surrogate pairs in unicode escapes now properly handles
   incremental parsing.
* Fix incremental parsing of numbers, especially those with exponents, e.g.
   so parsing "[0", "e+", "-]" now properly returns an error.
  Strict mode now rejects missing exponents ("0e").
* Successfully return number objects at the top level even when they are
   followed by a "-", "." or "e".  This makes parsing things like "123-45"
   behave consistently with things like "123xyz".

Other changes
-------------
* #589 - Detect broken RDRAND during initialization; also, fix segfault
    in the CPUID check.
* #592 - Fix integer overflows to prevert out of bounds write on large input.
* Protect against division by zero in linkhash, when creaed with zero size.
* #602 - Fix json_parse_uint64() internal error checking, leaving the retval
    untouched in more failure cases.
* #614 - Prevent truncation when custom double formatters insert extra \0's


***

0.14 (up to commit 9ed00a6, 2020/04/14)
=========================================

Deprecated and removed features:
--------------------------------
* bits.h has been removed
* lh_abort() has been removed
* lh_table_lookup() has been removed, use lh_table_lookup_ex() instead.
* Remove TRUE and FALSE defines, use 1 and 0 instead.

Build changes:
--------------
## Deprecated and removed features:
* bits.h has been removed
* lh_abort() has been removed
* lh_table_lookup() has been removed, use lh_table_lookup_ex() instead.
* Remove TRUE and FALSE defines, use 1 and 0 instead.
* autoconf support, including autogen.sh, has been removed.  See details about cmake, below.
* With the addition of json_tokener_get_parse_end(), access to internal fields of json_tokener, as well as use of many other symbols and types in json_tokener.h, is deprecated now.
* The use of Android.configure.mk to build for Android no longer works, and it is unknown how (or if) the new cmake-based build machinery can be used.
    * Reports of success, or pull requests to correct issues are welcome.

## Notable improvements and new features

### Builds and documentation
* Build machinery has been switched to CMake.  See README.md for details about how to build.
    * TL;DR: `mkdir build ; cd build ; cmake -DCMAKE_INSTALL_PREFIX=/some/path ../json-c ; make all test install`
    * To ease the transition, there is a `cmake-configure` wrapper that emulates the old autoconf-based configure script.
    * This has enabled improvements to the build on Windows system; also all public functions have been fixed to be properly exported.  For best results, use Visual Studio 2015 or newer.
* The json-c style guide has been updated to specify the use of clang-format, and all code has been reformatted.
    * Since many lines of code have trivial changes now, when using git blame, be sure to specify -w
* Numerous improvements have been made to the documentation including function effects on refcounts, when passing a NULL is safe, and so on.

### json_tokener changes
* Added a json_tokener_get_parse_end() function to replace direct access of tok->char_offset.
    * The char_offset field, and the rest of the json_tokener structure remain exposed for now, but expect a future release to hide it like is done with json_object_private.h
* json_tokener_parse_ex() now accepts a new JSON_TOKENER_VALIDATE_UTF8 flag to validate that input is UTF8.
    * If validation fails, json_tokener_get_error(tok) will return json_tokener_error_parse_utf8_string (see enum json_tokener_error).

### Other changes and additions
* Add support for unsigned 64-bit integers, uint64_t, to gain one extra bit of magnitude for positive ints.
    * json_tokener will now parse values up to UINT64_MAX (18446744073709551615)
    * Existing methods returning int32_t or int64_t will cap out-of-range values at INT32_MAX or INT64_MAX, preserving existing behavior.
    * The implementation includes the possibility of easily extending this to larger sizes in the future.
* A total of 7 new functions were added:
    * json_object_get_uint64 ( struct json_object const* jso )
    * json_object_new_uint64 ( uint64_t i )
    * json_object_set_uint64 ( struct json_object* jso, uint64_t new_value )
    * json_parse_uint64 ( char const* buf, uint64_t* retval )
        * See description of uint64 support, above.
    * json_tokener_get_parse_end ( struct json_tokener* tok )
        * See details under "json_tokener changes", above.
    * json_object_from_fd_ex ( int fd, int in_depth )
        * Allows the max nesting depth to be specified.
    * json_object_new_null ( )
        * Simply returns NULL.  Its use is not recommended.
* The size of struct json_object has decreased from 96 bytes to 88 bytes.

### Testing
* Many updates were made to test cases, increasing code coverage.
* There is now a quick way (JSONC_TEST_TRACE=1) to turn on shell tracing in tests.
* To run tests, use `make test`; the old "check" target no longer exists.

## Significant bug fixes
For the full list of issues and pull requests since the previous release, please see issues_closed_for_0.14.md

* [Issue #389](https://github.com/json-c/json-c/issues/389): Add an assert to explicitly crash when _ref_count is corrupted, instead of a later "double free" error.
* [Issue #407](https://github.com/json-c/json-c/issues/407): fix incorrect casts in calls to ctype functions (isdigit and isspace) so we don't crash when asserts are enabled on certain platforms and characters > 128 are parsed.
* [Issue #418](https://github.com/json-c/json-c/issues/418): Fix docs for json_util_from_fd and json_util_from_file to say that they return NULL on failures.
* [Issue #422](https://github.com/json-c/json-c/issues/422): json_object.c:set errno in json_object_get_double() when called on a json_type_string object with bad content.
* [Issue #453](https://github.com/json-c/json-c/issues/453): Fixed misalignment in JSON serialization when JSON_C_TO_STRING_SPACED and JSON_C_TO_STRING_PRETTY are used together.
* [Issue #463](https://github.com/json-c/json-c/issues/463): fix newlocale() call to use LC_NUMERIC_MASK instead of LC_NUMERIC, and remove incorrect comment.
* [Issue #486](https://github.com/json-c/json-c/issues/486): append a missing ".0" to negative double values to ensure they are serialized as floating point numbers.
* [Issue #488](https://github.com/json-c/json-c/issues/488): use JSON_EXPORT on functions so they are properly exported on Windows.
* [Issue #539](https://github.com/json-c/json-c/issues/539): use an internal-only serializer function in json_object_new_double_s() to avoid potential conflicts with user code that uses the json_object_userdata_to_json_string serializer.

***

0.13.1 (up to commit 0f814e5, 2018/03/04)
=========================================

* Bump the major version of the .so library generated up to 4.0 to avoid
  conflicts because some downstream packagers of json-c had already done
  their own bump to ".so.3" for a much older 0.12 release.
* Add const size_t json_c_object_sizeof()
* Avoid invalid free (and thus a segfault) when ref_count gets < 0
* PR#394: fix handling of custom double formats that include a ".0"
* Avoid uninitialized variable warnings in json_object_object_foreach
* Issue #396: fix build for certain uClibc based systems.
* Add a top level fuzz directory for fuzzers run by OSS-Fuzz


0.13 (up to commit 5dae561, 2017/11/29)
=================================

This release, being three and a half years after the 0.12 branch (f84d9c),
   has quite a number of changes included.  The following is a sampling of
   the most significant ones.

Since the 0.12 release, 250 issues and pull requests have been closed.
See issues_closed_for_0.13.md for a complete list.


Deprecated and removed features:
--------------------------------
* All internal use of bits.h has been eliminated.  The file will be removed.
	Do not use: hexdigit(), error_ptr(), error_descrition() and it_error()
* lh_abort() is deprecated.  It will be removed.

Behavior changes:
-----------------
* Tighten the number parsing algorithm to raise errors instead of truncating
     the results.  For example 12.3.4 or 2015-01-15, which now return null.
	 See commit 99d8fc

* Use size_t for array length and size.  Platforms where sizeof(size_t) != sizeof(int) may not be backwards compatible
	See commits 45c56b, 92e9a5 and others.

* Check for failue when allocating memory, returning NULL and errno=ENOMEM.
	 See commit 2149a04.

* Change json_object_object_add() return type from void to int, and will return -1 on failures, instead of exiting. (Note: this is not an ABI change)

New features:
-------------
* We're aiming to follow RFC 7159 now.

* Add a couple of additional option to json_object_to_json_string_ext:
	JSON_C_TO_STRING_PRETTY_TAB
	JSON_C_TO_STRING_NOSLASHESCAPE

* Add a json_object_object_add_ex() function to allow for performance
	improvements when certain constraints are known to be true.

* Make serialization format of doubles configurable, in two different ways:
	Call json_object_set_serializer with json_object_double_to_json_string and a custom
	 format on each double object, or
	Call json_c_set_serialization_double_format() to set a global or thread-wide format.

* Add utility function for comparing json_objects - json_object_equal()

* Add a way to copy entire object trees: json_object_deep_copy()
* Add json_object_set_<type> function to modify the value of existing json_object's
 without the need to recreate them.  Also add a json_object_int_inc function to
 adjust an int's value.
* Add support for JSON pointer, RFC 6901.  See json_pointer.h
* Add a json_util_get_last_err() function to retrieve the string describing the
 cause of errors, instead of printing to stderr.
* Add perllike hash function for strings, and json_global_set_string_hash() 8f8d03d
* Add a json_c_visit() function to provide a way to iterate over a tree of json-c objects.

Notable bug fixes and other improvements:
-----------------------------------------
* Make reference increment and decrement atomic to allow passing json objects between threads.
* Fix json_object_object_foreach to avoid uninitialized variable warnings.
* Improve performance by removing unneeded data items from hashtable code and reducing duplicate hash computation.
* Improve performance by storing small strings inside json_object
* Improve performance of json_object_to_json_string by removing variadic printf. commit 9ff0f49
* Issue #371: fix parsing of "-Infinity", and avoid needlessly copying the input when doing so.
* Fix stack buffer overflow in json_object_double_to_json_string_format() - commit 2c2deb87
* Fix various potential null ptr deref and int32 overflows
* Issue #332: fix a long-standing bug in array_list_put_idx() where it would attempt to free previously free'd entries due to not checking the current array length.
* Issue #195: use uselocale() instead of setlocale() in json_tokener to behave better in threaded environments.
* Issue #275: fix out of bounds read when handling unicode surrogate pairs.
* Ensure doubles that happen to be a whole number are emitted with ".0" - commit ca7a19
* PR#331: for Visual Studio, use a snprintf/vsnprintf wrapper that ensures the string is terminated.
* Fix double to int cast overflow in json_object_get_int64.
* Clamp double to int32 when narrowing in json_object_get_int.
* Use strtoll() to parse ints - instead of sscanf
* Miscellaneous smaller changes, including removing unused variables, fixing warning
 about uninitialized variables adding const qualifiers, reformatting code, etc...

Build changes:
--------------
* Add Appveyor and Travis build support
* Switch to using CMake when building on Windows with Visual Studio.
	A dynamic .dll is generated instead of a .lib
	config.h is now generated, config.h.win32 should no longer be manually copied
* Add support for MacOS through CMake too.
* Enable silent build by default
* Link against libm when needed
* Add support for building with AddressSanitizer
* Add support for building with Clang
* Add a --enable-threading configure option, and only use the (slower) __sync_add_and_fetch()/__sync_sub_and_fetch() function when it is specified.

List of new functions added:
----------------------------
### json_object.h
* array_list_bsearch()
* array_list_del_idx()
* json_object_to_json_string_length()
* json_object_get_userdata()
* json_object_set_userdata()
* json_object_object_add_ex()
* json_object_array_bsearch()
* json_object_array_del_idx()
* json_object_set_boolean()
* json_object_set_int()
* json_object_int_inc()
* json_object_set_int64()
* json_c_set_serialization_double_format()
* json_object_double_to_json_string()
* json_object_set_double()
* json_object_set_string()
* json_object_set_string_len()
* json_object_equal()
* json_object_deep_copy()

### json_pointer.h
* json_pointer_get()
* json_pointer_getf()
* json_pointer_set()
* json_pointer_setf()

### json_util.h
* json_object_from_fd()
* json_object_to_fd()
* json_util_get_last_err()

### json_visit.h
* json_c_visit()

### linkhash.h
* json_global_set_string_hash()
* lh_table_resize()

### printbuf.h
* printbuf_strappend()


0.12.1
======

  * Minimal changes to address compile issues.

0.12
====

  * Address security issues:
    * CVE-2013-6371: hash collision denial of service
    * CVE-2013-6370: buffer overflow if size_t is larger than int

  * Avoid potential overflow in json_object_get_double

  * Eliminate the mc_abort() function and MC_ABORT macro.

  * Make the json_tokener_errors array local.  It has been deprecated for
     a while, and json_tokener_error_desc() should be used instead.

  * change the floating point output format to %.17g so values with
     more than 6 digits show up in the output.

  * Remove the old libjson.so name compatibility support.  The library is
      only created as libjson-c.so now and headers are only installed
      into the ${prefix}/json-c directory.

  * When supported by the linker, add the -Bsymbolic-functions flag.

  * Various changes to fix the build on MSVC.

  * Make strict mode more strict:
    * number must not start with 0
    * no single-quote strings
    * no comments
    * trailing char not allowed
    * only allow lowercase literals

  * Added a json_object_new_double_s() convenience function to allow
    an exact string representation of a double to be specified when
    creating the object and use it in json_tokener_parse_ex() so
    a re-serialized object more exactly matches the input.

  * Add support NaN and Infinity


0.11
====

  * IMPORTANT: the name of the library has changed to libjson-c.so and
     the header files are now in include/json-c.
     The pkgconfig name has also changed from json to json-c.
     You should change your build to use appropriate -I and -l options.
     A compatibility shim is in place so builds using the old name will
     continue to work, but that will be removed in the next release.
  * Maximum recursion depth is now a runtime option.
     json_tokener_new() is provided for compatibility.
     json_tokener_new_ex(depth)
  * Include json_object_iterator.h in the installed headers.
  * Add support for building on Android.
  * Rewrite json_object_object_add to replace just the value if the key already exists so keys remain valid.
  * Make it safe to delete keys while iterating with the json_object_object_foreach macro.
  * Add a json_set_serializer() function to allow the string output of a json_object to be customized.
  * Make float parsing locale independent.
  * Add a json_tokener_set_flags() function and a JSON_TOKENER_STRICT flag.
  * Enable -Werror when building.
  * speed improvements to parsing 64-bit integers on systems with working sscanf
  * Add a json_object_object_length function.
  * Fix a bug (buffer overrun) when expanding arrays to more than 64 entries.

0.10
====

  * Add a json_object_to_json_string_ext() function to allow output to be
     formatted in a more human readable form.
  * Add json_object_object_get_ex(), a NULL-safe get object method, to be able
     to distinguish between a key not present and the value being NULL.
  * Add an alternative iterator implementation, see json_object_iterator.h
  * Make json_object_iter public to enable external use of the
     json_object_object_foreachC macro.
  * Add a printbuf_memset() function to provide an effecient way to set and
     append things like whitespace indentation.
  * Adjust json_object_is_type and json_object_get_type so they return
      json_type_null for NULL objects and handle NULL passed to
      json_objct_object_get().
  * Rename boolean type to json_bool.
  * Fix various compile issues for Visual Studio and MinGW.
  * Allow json_tokener_parse_ex() to be re-used to parse multiple object.
     Also, fix some parsing issues with capitalized hexadecimal numbers and
     number in E notation.
  * Add json_tokener_get_error() and json_tokener_error_desc() to better
     encapsulate the process of retrieving errors while parsing.
  * Various improvements to the documentation of many functions.
  * Add new json_object_array_sort() function.
  * Fix a bug in json_object_get_int(), which would incorrectly return 0
    when called on a string type object.
    Eric Haszlakiewicz
  * Add a json_type_to_name() function.
    Eric Haszlakiewicz
  * Add a json_tokener_parse_verbose() function.
    Jehiah Czebotar
  * Improve support for null bytes within JSON strings.
    Jehiah Czebotar
  * Fix file descriptor leak if memory allocation fails in json_util
    Zachary Blair, zack_blair at hotmail dot com
  * Add int64 support. Two new functions json_object_net_int64 and
    json_object_get_int64. Binary compatibility preserved.
    Eric Haszlakiewicz, EHASZLA at transunion com
    Rui Miguel Silva Seabra, rms at 1407 dot org
  * Fix subtle bug in linkhash where lookup could hang after all slots
    were filled then successively freed.
    Spotted by Jean-Marc Naud, j dash m at newtraxtech dot com
  * Make json_object_from_file take const char *filename
    Spotted by Vikram Raj V, vsagar at attinteractive dot com
  * Add handling of surrogate pairs (json_tokener.c, test4.c, Makefile.am)
    Brent Miller, bdmiller at yahoo dash inc dot com
  * Correction to comment describing printbuf_memappend in printbuf.h
    Brent Miller, bdmiller at yahoo dash inc dot com

0.9
===
  * Add README.html README-WIN32.html config.h.win32 to Makefile.am
    Michael Clark, <michael@metaparadigm.com>
  * Add const qualifier to the json_tokener_parse functions
    Eric Haszlakiewicz, EHASZLA at transunion dot com
  * Rename min and max so we can never clash with C or C++ std library
    Ian Atha, thatha at yahoo dash inc dot com
  * Fix any noticeable spelling or grammar errors.
  * Make sure every va_start has a va_end.
  * Check all pointers for validity.
    Erik Hovland, erik at hovland dot org
  * Fix json_object_get_boolean to return false for empty string
    Spotted by Vitaly Kruglikov, Vitaly dot Kruglikov at palm dot com
  * optimizations to json_tokener_parse_ex(), printbuf_memappend()
    Brent Miller, bdmiller at yahoo dash inc dot com
  * Disable REFCOUNT_DEBUG by default in json_object.c
  * Don't use this as a variable, so we can compile with a C++ compiler
  * Add casts from void* to type of assignment when using malloc
  * Add #ifdef __cplusplus guards to all of the headers
  * Add typedefs for json_object, json_tokener, array_list, printbuf, lh_table
    Michael Clark, <michael@metaparadigm.com>
  * Null pointer dereference fix. Fix json_object_get_boolean strlen test
    to not return TRUE for zero length string. Remove redundant includes.
    Erik Hovland, erik at hovland dot org
  * Fixed warning reported by adding -Wstrict-prototypes
    -Wold-style-definition to the compilatin flags.
    Dotan Barak, dotanba at gmail dot com
  * Add const correctness to public interfaces
    Gerard Krol, g dot c dot krol at student dot tudelft dot nl

0.8
===
  * Add va_end for every va_start
    Dotan Barak, dotanba at gmail dot com
  * Add macros to enable compiling out debug code
    Geoffrey Young, geoff at modperlcookbook dot org
  * Fix bug with use of capital E in numbers with exponents
    Mateusz Loskot, mateusz at loskot dot net
  * Add stddef.h include
  * Patch allows for json-c compile with -Werror and not fail due to
    -Wmissing-prototypes -Wstrict-prototypes -Wmissing-declarations
    Geoffrey Young, geoff at modperlcookbook dot org

0.7
===
  * Add escaping of backslash to json output
  * Add escaping of foward slash on tokenizing and output
  * Changes to internal tokenizer from using recursion to
    using a depth state structure to allow incremental parsing

0.6
===
  * Fix bug in escaping of control characters
    Johan Björklund, johbjo09 at kth dot se
  * Remove include "config.h" from headers (should only
    be included from .c files)
    Michael Clark <michael@metaparadigm.com>

0.5
===
  * Make headers C++ compatible by change *this to *obj
  * Add ifdef C++ extern "C" to headers
  * Use simpler definition of min and max in bits.h
    Larry Lansing, llansing at fuzzynerd dot com

  * Remove automake 1.6 requirement
  * Move autogen commands into autogen.sh. Update README
  * Remove error pointer special case for Windows
  * Change license from LGPL to MIT
    Michael Clark <michael@metaparadigm.com>

0.4
===
  * Fix additional error case in object parsing
  * Add back sign reversal in nested object parse as error pointer
    value is negative, while error value is positive.
    Michael Clark <michael@metaparadigm.com>

0.3
===
  * fix pointer arithmetic bug for error pointer check in is_error() macro
  * fix type passed to printbuf_memappend in json_tokener
  * update autotools bootstrap instructions in README
    Michael Clark <michael@metaparadigm.com>

0.2
===
  * printbuf.c - C. Watford (christopher.watford@gmail.com)
    Added a Win32/Win64 compliant implementation of vasprintf
  * debug.c - C. Watford (christopher.watford@gmail.com)
    Removed usage of vsyslog on Win32/Win64 systems, needs to be handled
    by a configure script
  * json_object.c - C. Watford (christopher.watford@gmail.com)
    Added scope operator to wrap usage of json_object_object_foreach, this
    needs to be rethought to be more ANSI C friendly
  * json_object.h - C. Watford (christopher.watford@gmail.com)
    Added Microsoft C friendly version of json_object_object_foreach
  * json_tokener.c - C. Watford (christopher.watford@gmail.com)
    Added a Win32/Win64 compliant implementation of strndup
  * json_util.c - C. Watford (christopher.watford@gmail.com)
    Added cast and mask to suffice size_t v. unsigned int conversion
    correctness
  * json_tokener.c - sign reversal issue on error info for nested object parse
    spotted by Johan Björklund (johbjo09 at kth.se)
  * json_object.c - escape " in json_escape_str
  * Change to automake and libtool to build shared and static library
    Michael Clark <michael@metaparadigm.com>

0.1
===
  * initial release