py36-gnureadline @6.3.3_1: python3.6 crashes with malloc: pointer being freed was not allocated

[mndavidoff (Monte Davidoff)]

Installing py36-gnureadline causes python3.6 to crash.

Without py36-gnureadline:

$ port installed py36-gnureadline
None of the specified ports are installed.
$ python3.6
Python 3.6.0 (default, Dec 28 2016, 22:59:42) 
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 1+2
3
>>> ^D

With py36-gnureadline:

$ port installed py36-gnureadline
The following ports are currently installed:
  py36-gnureadline @6.3.3_1 (active)
$ python3.6
Python 3.6.0 (default, Dec 28 2016, 22:59:42) 
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 1+2
Python(53168,0x7fffd7e0f3c0) malloc: *** error for object 0x109b63698: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
Abort trap: 6

Curiously, this problem does not affect ipython:

$ ipython3-3.6
Python 3.6.0 (default, Dec 28 2016, 22:59:42) 
Type "copyright", "credits" or "license" for more information.

IPython 5.1.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: 1+2
Out[1]: 3

In [2]: exit

[mndavidoff (Monte Davidoff)]

There is some discussion of this issue in #48807. A workaround is to install python36 +readline.

[jmroot (Joshua Root)]

In eaa66e310099aabde7344c7b74f73cdbf07b7d1a/macports-ports:

py-gnureadline: update to latest upstream commit

Now works with python 3.6.
Also incorporated patches from py-readline.

Fixes: #53176