[ python-Bugs-1501291 ] python/ncurses bug in 2.4.3 with extended ascii

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Bugs item #1501291, was opened at 2006-06-05 16:34
Message generated for change (Comment added) made by unixops1234
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Category: Extension Modules
Group: Python 2.4
Status: Open
Resolution: None
Priority: 5
Submitted By: UnixOps (unixops1234)
Assigned to: Nobody/Anonymous (nobody)
Summary: python/ncurses bug in 2.4.3 with extended ascii

Initial Comment:
There is a problem displaying extended ascii characters
in ncurses through python, which does not exist in
versions prior to 2.4.2. I am running RedHat Enterprise
Linux WS 3 with updated patches, using the system
version of ncurses (ncurses-5.3-9.4 and devel). When
building a vanilla python 2.4.3 from source, printing
extended ascii characters in ncurses fails:

$ cat test.py
import curses

screen = curses.initscr()

screen.addstr("\x80")

screen.getch()
curses.endwin()

$ python test.py
Traceback (most recent call last):hon test.py
File "test.py", line 5, in ?
screen.addstr("\x80")
_curses.error: addstr() returned ERR

This should produce a blank ncurses screen, rather than
the addstr() error. I've been able to confirm that it
works with python 2.4.2 and earlier. 

To ensure that ncurses was able to display the
character, I wrote this test C program: 

$ cat test.c
#include <ncurses.h>

int main()
{
initscr();
int rtn = addstr("\x80");
getch(); 
endwin();
printf("The return value was %d.\n",rtn);
return 0;
}

$ gcc test.c -o test -lncurses
$ ./test

This works just fine, so I think the problem lies
somewhere in the python interface to ncurses. Python
can print this character without errors when not using
ncurses. Perhaps ncurses is expecting different
initialization than python is providing.  

I've also tested this on a RedHat WS 4 machine, where
it works just fine. This system is running
ncurses-5.4-13 and ncurses-devel-5.4-13. It seems the
newer release of python has changed something that the
older versions of ncurses are unable to handle.  

Can this be fixed in _cursesmodule.c?

----------------------------------------------------------------------

>Comment By: UnixOps (unixops1234)
Date: 2006-06-08 14:02

Message:
Logged In: YES 
user_id=1534776

I tried recompiling Python with the patch from bug #1464056
that fixes the panelw linking in _curses_panel.so. It now
properly links with libpanelw instead of libpanel, but the
original problem persists. I still get "_curses.error:
addstr() returned ERR" when running the test code.

----------------------------------------------------------------------

Comment By: Martin v. Löwis (loewis)
Date: 2006-06-08 11:58

Message:
Logged In: YES 
user_id=21627

I doubt it can be fixed in _cursesmodule. Notice that Python
links with ncursesw now, not with ncurses anymore. There is
a bug in 2.4.3 which links, apparently incorrectly, with
panel instead of panelw. Try changing that and see whether
it helps.

----------------------------------------------------------------------

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