Patchwork [1,of,2] pycompat: stop setting LC_CTYPE unconditionally

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Submitter Manuel Jacob
Date June 27, 2020, 8:58 p.m.
Message ID <52c536124224ca4e87ae.1593291493@tmp>
Download mbox | patch
Permalink /patch/46581/
State Superseded
Headers show

Comments

Manuel Jacob - June 27, 2020, 8:58 p.m.
# HG changeset patch
# User Manuel Jacob <me@manueljacob.de>
# Date 1593284746 -7200
#      Sat Jun 27 21:05:46 2020 +0200
# Node ID 52c536124224ca4e87aee09cdff7ded520d6d40d
# Parent  94987aadb22cee1d7da52f365b3f532a94bbd4a6
# EXP-Topic with_lc_type
pycompat: stop setting LC_CTYPE unconditionally

Changeset a25343d16ebe aimed to align how LC_CTYPE is initialized across Python
versions. However, as Yuya Nishihara pointed out, it changes the behavior of
some str methods on Python 2.

Curses requires that LC_CTYPE is initialized correctly. Therefore LC_CTYPE is
set while curses is used and reset afterwards. It shouldn’t be a problem that
some str methods behave differently on Python 2 while curses is used. At least
it’s not a regression compared to what was done before d2227d4c9e6b.

This again breaks non-ASCII filenames passed to the Subversion bindings on
Python 2. Since it didn’t work before a25343d16ebe, it’s however not really a
regression. A separate patch will be sent.
Yuya Nishihara - June 28, 2020, 5:55 a.m.
On Sat, 27 Jun 2020 22:58:13 +0200, Manuel Jacob wrote:
> # HG changeset patch
> # User Manuel Jacob <me@manueljacob.de>
> # Date 1593284746 -7200
> #      Sat Jun 27 21:05:46 2020 +0200
> # Node ID 52c536124224ca4e87aee09cdff7ded520d6d40d
> # Parent  94987aadb22cee1d7da52f365b3f532a94bbd4a6
> # EXP-Topic with_lc_type
> pycompat: stop setting LC_CTYPE unconditionally

> --- a/mercurial/pycompat.py
> +++ b/mercurial/pycompat.py
> @@ -10,6 +10,7 @@
>  
>  from __future__ import absolute_import
>  
> +import contextlib
>  import getopt
>  import inspect
>  import json
> @@ -105,13 +106,22 @@
>  # initialized. Since CPython commit 177d921c8c03d30daa32994362023f777624b10d,
>  # LC_CTYPE is always initialized. If we require Python 3.8+, we should re-check
>  # if we can remove this code.
> -if locale.setlocale(locale.LC_CTYPE, None) == 'C':
> -    try:
> -        locale.setlocale(locale.LC_CTYPE, '')
> -    except locale.Error:
> -        # The likely case is that the locale from the environment variables is
> -        # unknown.
> -        pass
> +@contextlib.contextmanager
> +def with_lc_ctype():
> +    oldloc = locale.setlocale(locale.LC_CTYPE, None)
> +    if oldloc == 'C':
> +        try:
> +            try:
> +                locale.setlocale(locale.LC_CTYPE, '')
> +            except locale.Error:
> +                # The likely case is that the locale from the environment
> +                # variables is unknown.
> +                pass
> +            yield
> +        finally:
> +            locale.setlocale(locale.LC_CTYPE, oldloc)
> +    else:
> +        yield

Let's move this function to util.py. Other than that, the patch looks
good to me.

Patch

diff --git a/hgext/histedit.py b/hgext/histedit.py
--- a/hgext/histedit.py
+++ b/hgext/histedit.py
@@ -1710,7 +1710,8 @@ 
         ctxs = []
         for i, r in enumerate(revs):
             ctxs.append(histeditrule(ui, repo[r], i))
-        rc = curses.wrapper(functools.partial(_chisteditmain, repo, ctxs))
+        with pycompat.with_lc_ctype():
+            rc = curses.wrapper(functools.partial(_chisteditmain, repo, ctxs))
         curses.echo()
         curses.endwin()
         if rc is False:
diff --git a/mercurial/crecord.py b/mercurial/crecord.py
--- a/mercurial/crecord.py
+++ b/mercurial/crecord.py
@@ -569,7 +569,8 @@ 
     if util.safehasattr(signal, b'SIGTSTP'):
         origsigtstp = signal.getsignal(signal.SIGTSTP)
     try:
-        curses.wrapper(chunkselector.main)
+        with pycompat.with_lc_ctype():
+            curses.wrapper(chunkselector.main)
         if chunkselector.initexc is not None:
             raise chunkselector.initexc
         # ncurses does not restore signal handler for SIGTSTP
diff --git a/mercurial/pycompat.py b/mercurial/pycompat.py
--- a/mercurial/pycompat.py
+++ b/mercurial/pycompat.py
@@ -10,6 +10,7 @@ 
 
 from __future__ import absolute_import
 
+import contextlib
 import getopt
 import inspect
 import json
@@ -105,13 +106,22 @@ 
 # initialized. Since CPython commit 177d921c8c03d30daa32994362023f777624b10d,
 # LC_CTYPE is always initialized. If we require Python 3.8+, we should re-check
 # if we can remove this code.
-if locale.setlocale(locale.LC_CTYPE, None) == 'C':
-    try:
-        locale.setlocale(locale.LC_CTYPE, '')
-    except locale.Error:
-        # The likely case is that the locale from the environment variables is
-        # unknown.
-        pass
+@contextlib.contextmanager
+def with_lc_ctype():
+    oldloc = locale.setlocale(locale.LC_CTYPE, None)
+    if oldloc == 'C':
+        try:
+            try:
+                locale.setlocale(locale.LC_CTYPE, '')
+            except locale.Error:
+                # The likely case is that the locale from the environment
+                # variables is unknown.
+                pass
+            yield
+        finally:
+            locale.setlocale(locale.LC_CTYPE, oldloc)
+    else:
+        yield
 
 
 if ispy3: