curses: do not initialize LC_ALL to user settings (issue6358)

701341f57ceb moved the setlocale() call to right before curses was used. This
didn’t fully solve the problem it was supposed to solve (locale-dependent
functions, like date formatting/parsing), but only postponed it.

Initializing LC_CTYPE seems to be sufficient for curses to work correctly.
Luckily this is already done at interpreter startup on modern Python versions
and, since recently, by Mercurial in the pycompat module in all other cases.

hgext/histedit.py

@@ -201,7 +201,6 b' except ImportError:'
     termios = None
 
 import functools
-import locale
 import os
 import struct
 
@@ -1711,10 +1710,6 b' def _chistedit(ui, repo, freeargs, opts)'
         ctxs = []
         for i, r in enumerate(revs):
             ctxs.append(histeditrule(ui, repo[r], i))
-        # Curses requires setting the locale or it will default to the C
-        # locale. This sets the locale to the user's default system
-        # locale.
-        locale.setlocale(locale.LC_ALL, '')
         rc = curses.wrapper(functools.partial(_chisteditmain, repo, ctxs))
         curses.echo()
         curses.endwin()

mercurial/crecord.py

@@ -10,7 +10,6 b''
 
 from __future__ import absolute_import
 
-import locale
 import os
 import re
 import signal
@@ -574,9 +573,6 b' def chunkselector(ui, headerlist, operat'
     """
     ui.write(_(b'starting interactive selection\n'))
     chunkselector = curseschunkselector(headerlist, ui, operation)
-    # This is required for ncurses to display non-ASCII characters in
-    # default user locale encoding correctly.  --immerrr
-    locale.setlocale(locale.LC_ALL, '')
     origsigtstp = sentinel = object()
     if util.safehasattr(signal, b'SIGTSTP'):
         origsigtstp = signal.getsignal(signal.SIGTSTP)