   Copyright (C) 2019, 2020, 2021, 2022 Free Software Foundation, Inc.
   
   Copying and distribution of this file, with or without modification,
   are permitted in any medium without royalty provided the copyright
   notice and this notice are preserved.

Changes from 5.1.x to 5.2.0
---------------------------

*****************************************************************************
* MPFR mode (the -M option) is now ON PAROLE.  This feature is now being    *
* supported by a volunteer in the development team and not by the primary   *
* maintainer.  If this situation changes, then the feature will be removed. *
* For more information see this section in the manual:                      *
* https://www.gnu.org/software/gawk/manual/html_node/MPFR-On-Parole.html    *
*****************************************************************************

1. Infrastructure upgrades: Libtool 2.4.7, Bison 3.8.2.

2. Numeric scalars now compare in the same way as C for the relational
   operators. Comparison order for sorting has not changed.  This only
   makes a difference when comparing Infinity and NaN values with
   regular numbers; it should not be noticeable most of the time.

3. If the AWK_HASH environment variable is set to "fnv1a" gawk will
   use the FNV1-A hash function for associative arrays.

4. The CMake infrastructure has been removed. In the five years it was in
   the tree, nobody used it, and it was not updated.

5. There is now a new function, mkbool(), that creates Boolean-typed
   values.  These values *are* numbers, but they are also tagged as
   Boolean. This is mainly for use with data exchange to/from languages
   or environments that support real Boolean values. See the manual
   for details.

6. As BWK awk has supported interval expressions since 2019, they are
   now enabled even if --traditional is supplied. The -r/--re-interval option
   remains, but it does nothing.

7. The rwarray extension has two new functions, writeall() and readall(),
   for saving / restoring all of gawk's variables and arrays.

8. The new `gawkbug' script should be used for reporting bugs.

9. The manual page (doc/gawk.1) has been considerably reduced in size.
   Wherever possible, details were replaced with references to the online
   copy of the manual.

10. Gawk now supports Terence Kelly's "persistent malloc" (pma),
    allowing gawk to preserve its variables, arrays and user-defined
    functions between runs. THIS IS AN EXPERIMENTAL FEATURE!
   
    For more information, see the manual. A new pm-gawk.1 man page
    is included, as is a separate user manual that focuses on the feature.

11. Support for OS/2 has been removed. It was not being actively
    maintained.

12. Similarly, support for DJGPP has been removed. It also was not
    being actively maintained.

13. VAX/VMS is no longer supported, as it can no longer be tested.
    The files for it remain in the distribution but will be removed
    eventually.

14. Some subtle issues with untyped array elements being passed to
    functions have been fixed.

15. Syntax errors are now immediately fatal. This prevents problems
    with errors from fuzzers and other such things.

16. There have been numerous minor code cleanups and bug fixes. See the
    ChangeLog for details.

Changes from 5.1.1 to 5.1.x
---------------------------

1. Infrastructure upgrades: Automake 1.16.5, Texinfo 6.8.

2. The rwarray extension now supports writing and reading GMP and
   MPFR values. As a result, a bug in the API code was fixed.

Changes from 5.1.0 to 5.1.1
---------------------------

1. Infrastructure upgrades: Bison 3.8, Gettext 0.20.2, Automake 1.16.4,
   and (will wonders never cease) Autoconf 2.71.

2. asort and asorti now allow FUNCTAB and SYMTAB as the first argument if a
   second destination array is supplied. Similarly, using either array as
   the second argument is now a fatal error. Additionally, using either
   array as the destination for split(), match(), etc. also causes a
   fatal error.

3. The new -I/--trace option prints a trace of the byte codes as they
   are executed.

4. A number of subtle bugs relating to MPFR mode that caused differences
   between regular operation and MPFR mode have been fixed.

5. The API now handles MPFR/GMP values slightly differently, requiring
   different memory management for those values. See the manual for the
   details if you have an extension using those values.  As a result,
   the minor version was incremented.

6. $0 and the fields are now cleared before starting a BEGINFILE rule.

7. The duplication of m4 and build-aux directories between the main
   directory and the extension directory has been removed. This
   simplifies the distribution.

8. The test suite has been improved, making it easier to run the entire
   suite with -M. Use `GAWK_TEST_ARGS=-M make check' to do so.

9. Profiling and pretty-printing output has been modified slightly so
   that functions are presented in a reasonable order with respect
   to the namespaces that contain them.

10. Several example programs in the manual have been updated to their
    modern POSIX equivalents.

11. A number of examples in doc/gawkinet.texi have been updated for
    current times. Thanks to Juergen Kahrs for the work.

12. Handling of Infinity and NaN values has been improved.

13. There has been a general tightening up of the use of const and
    of types.

14. The "no effect" lint warnings have been fixed up and now behave
    more sanely.

15. The manual has been updated with much more information about what is
    and is not a bug, and the changes in the gawk mailing lists.

16. The behavior of strongly-typed regexp constants when passed as the
    third argument to sub() or gsub() has been clarified in the code and
    in the manual.

17. Similar to item #4 above, division by zero is now fatal in MPFR
    mode, as it is in regular mode.

18. There have been numerous minor code cleanups and bug fixes. See the
    ChangeLog for details.

Changes from 5.0.1 to 5.1.0
---------------------------

1. The major version of the API is bumped to 3, something that should
   have happened at the 5.0.0 release but didn't.

2. A number of memory leak issues have been fixed.

3. Infrastructure upgrades: Bison 3.5.4, Texinfo 6.7, Gettext 0.20.1,
   Automake 1.16.2.

4. The indexing in the manual has been thoroughly revised, in particular
   making use of the facilities in Texinfo 6.7.  That version (or newer)
   must be used to format the manual.

5. MSYS2 is now supported out-of-the-box by configure.

6. Several bugs have been fixed.  See the ChangeLog for details.

Changes from 5.0.0 to 5.0.1
---------------------------

1. A number of ChangeLog.1 files that were left out of the distribution
   have been restored.

2. Multiple syntax errors should no longer be able to cause a core dump.

3. Sandbox mode now disallows assigning new filename values in ARGV that
   were not there when gawk was invoked.

4. There are many small documentation improvements in the manual.

5. The new argument "no-ext" to --lint disables ``XXX is a gawk extension''
   lint warnings.

6. Infrastructure upgrades: Bison 3.4.

7. A number of bugs, some of them quite significant, have been fixed.
   See the ChangeLog for details.

Changes from 4.2.1 to 5.0.0
---------------------------

1. Support for the POSIX standard %a and %A printf formats has been added.

2. The test infrastructure has been greatly improved, simplifying the
   contents of test/Makefile.am and making it possible to generate
   pc/Makefile.tst from test/Makefile.in.

3. The regex routines have been replaced with those from GNULIB, allowing
   me to stop carrying forward decades of changes against the original
   ones from GLIBC.

4. Infrastructure upgrades: Bison 3.3, Automake 1.16.1, Gettext 0.19.8.1,
   makeinfo 6.5.

5. The undocumented configure option and code that enabled the use of
   non-English "letters" in identifiers is now gone.

6. The `--with-whiny-user-strftime' configuration option is now gone.

7. The code now makes some stronger assumptions about a C99 environment.

8. PROCINFO["platform"] yields a string indicating the platform for
   which gawk was compiled.

9. Writing to elements of SYMTAB that are not variable names now
   causes a fatal error. THIS CHANGES BEHAVIOR.

10. Comment handling in the pretty-printer has been reworked almost completely
    from scratch. As a result, comments in many corner cases that were
    previously lost are now included in the formatted output.

11. Namespaces have been implemented! See the manual.  One consequence of this
    is that files included with -i, read with -f, and command line program
    segments must all be self-contained syntactic units. E.g., you can no
    longer do something like this:

   	gawk -e 'BEGIN {' -e 'print "hello" }'

12. Gawk now uses the locale settings for ignoring case in single byte
    locales, instead of hardwiring in Latin-1.

13. A number of bugs, some of them quite significant, have been fixed.
    See the ChangeLog for details.
