Fix: term: unset env COLUMNS and ROWS

A bug in python stardard library, python/cpython#100516, make
environment variables, `COLUMNS` and `ROWS` to be added at fork. These
environment variables may make some of the commands called by crmsh to
truncate its output even if those commands are not writing to the
terminal.

These variables is set when bash enables its `checkwinsize` option. As
crmsh is able to read terminal size with curses, these variables are
unneeded and may be out of sync with actual terminal size.

crmsh/term.py

@@ -1,6 +1,6 @@
 # Copyright (C) 2008-2011 Dejan Muhamedagic <[email protected]>
 # See COPYING for license information.
-
+import os
 import sys
 import re
 # from: http://code.activestate.com/recipes/475116/
@@ -151,6 +151,7 @@ def init():
     from . import config
     if not _term_stream.isatty() and 'color-always' not in config.color.style:
         return
+    _ignore_environ()
     # Check the terminal type.  If we fail, then assume that the
     # terminal has no capabilities.
     try:
@@ -177,4 +178,12 @@ def is_color(s):
     return hasattr(colors, s.upper())
 
 
+def _ignore_environ():
+    """Ignore environment variable COLUMNS and ROWS"""
+    # See https://bugzilla.suse.com/show_bug.cgi?id=1205925
+    # and https://gitlab.com/procps-ng/procps/-/blob/c415fc86452c933716053a50ab1777a343190dcc/src/ps/global.c#L279
+    for name in ["COLUMNS", "ROWS"]:
+        if name in os.environ:
+            del os.environ[name]
+
 # vim:ts=4:sw=4:et: