[Python-checkins] [python/cpython] fae8f4: bpo-29854: Fix segfault in call_readline() (GH-728...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/python/cpython
  Commit: fae8f4a9cb88a68eb14750cbb8ddf8740fd67b8b
      https://github.com/python/cpython/commit/fae8f4a9cb88a68eb14750cbb8ddf8740fd67b8b
  Author: Nir Soffer <nirsof at gmail.com>
  Date:   2017-07-07 (Fri, 07 Jul 2017)

  Changed paths:
    M Lib/test/test_readline.py
    A Misc/NEWS.d/next/Library/2017-07-07-02-18-57.bpo-29854.J8wKb_.rst
    M Modules/readline.c

  Log Message:
  -----------
  bpo-29854: Fix segfault in call_readline() (GH-728)

If history-length is set in .inputrc, and the history file is double the
history size (or more), history_get(N) returns NULL, and python
segfaults. Fix that by checking for NULL return value.

It seems that the root cause is incorrect handling of bigger history in
readline, but Python should not segfault even if readline returns
unexpected value.

This issue affects only GNU readline. When using libedit emulation
system history size option does not work.