because (essentially) I didn't realise that PY_BEGIN/END_ALLOW_THREADS
actually expanded to nothing under a no-threads build, so if you somehow
NULLed out the threadstate (e.g. by calling PyThread_SaveThread) it would
stay NULLed when you return to Python. Argh!
Backport candidate.
[ 1166660 ] The readline module can cause python to segfault
It seems to me that the code I'm rewriting here attempted to call any
user-supplied hook functions using the thread state of the thread that
called the hook-setting function, as opposed to that of the thread
that is currently executing. This doesn't work, in general.
Fix this by using the PyGILState API (It wouldn't be that hard to
define a dummy version of said API when #ifndef WITH_THREAD, would
it?).
Also, check the conversion to integer of the return value of a hook
function for errors (this problem was mentioned in the ipython bug
report linked to in the above bug).
[ 960406 ] unblock signals in threads
although the changes do not correspond exactly to any patch attached to
that report.
Non-main threads no longer have all signals masked.
A different interface to readline is used.
The handling of signals inside calls to PyOS_Readline is now rather
different.
These changes are all a bit scary! Review and cross-platform testing
much appreciated.
METH_NOARGS functions are still called with two arguments, one NULL,
so put that back into the function definitions (I didn't know this
until recently).
Make get_history_length() METH_NOARGS.
Check for readline 2.2 features. This should make it possible to
compile readline.c again with GNU readline versions 2.0 or 2.1; this
ability was removed in readline.c rev. 2.49. Apparently the older
versions are still in widespread deployment on older Solaris
installations. With an older readline, completion behavior is subtly
different (a space is always added).
readline in all python versions is configured
to append a 'space' character for a successful
completion. But for almost all python expressions
'space' is not wanted (see coding conventions PEP 8).
For example if you have a function 'longfunction'
and you type 'longf<TAB>' you get 'longfunction '
as a completion. note the unwanted space at the
end.
The patch fixes this behaviour by setting readline's
append_character to '\0' which means don't append
anything. This doesn't work with readline < 2.1
(AFAIK nowadays readline2.2 is in good use).
An alternative approach would be to make the
append_character
accessable from python so that modules like
the rlcompleter.py can set it to '\0'.
[Ed.: I think expecting readline >= 2.2 is fine. If a completer wants
another character they can append that to the keyword in the list.]
This was submitted by Moshe, but apparently he's too busy to check it
in himself. He wrote:
Here is a function in GNU readline called add_history,
which is used to manage the history list. Though Python
uses this function internally, it does not expose it to
the Python programmer. This patch adds direct interface
to this function with documentation.
This could be used by friendly modules to "seed" the
history with commands.
This patch allows the readline module to build cleanly with GNU
readline 4.2 without breaking the build for earlier GNU readline
versions. The configure script checks for the presence of
rl_completion_matches in libreadline.
always:
- #undef HAVE_CONFIG_H (because otherwise chardefs.h tries to include
strings.h)
- #include readline.h and history.h
and we never declare any readline function prototypes ourselves.
This makes it compile with readline 4.2, albeit with a few warnings.
Some of the remaining warnings are about completion_matches(), which
is renamed to rl_completion_matches().
I've tested it with various other versions, from 2.0 up, and they all
seem to work (some with warnings) -- but only on Red Hat Linux 6.2.
Fixing the warnings for readline 4.2 would break compatibility with
3.0 (and maybe even earlier versions), and readline doesn't seem to
have a way to test for its version at compile time, so I'd rather
leave the warnings in than break compilation with older versions.
Michael W. Hudson
Martin v. Löwis
Hye-Shik Chang
Neal Norwitz
Skip Montanaro
Nicholas Bastin
Guido van Rossum
Mark Hammond
Neil Schemenauer
Andrew MacIntyre
Tim Peters
Marc-André Lemburg
Fred Drake