git/gettext.c
Karsten Blees 090d1e8477 gettext: always use UTF-8 on native Windows
On native Windows, Git exclusively uses UTF-8 for console output (both
with MinTTY and native Win32 Console). Gettext uses `setlocale()` to
determine the output encoding for translated text, however, MSVCRT's
`setlocale()` does not support UTF-8. As a result, translated text is
encoded in system encoding (as per `GetAPC()`), and non-ASCII chars are
mangled in console output.

Side note: There is actually a code page for UTF-8: 65001. In practice,
it does not work as expected at least on Windows 7, though, so we cannot
use it in Git. Besides, if we overrode the code page, any process
spawned from Git would inherit that code page (as opposed to the code
page configured for the current user), which would quite possibly break
e.g. diff or merge helpers. So we really cannot override the code page.

In `init_gettext_charset()`, Git calls gettext's
`bind_textdomain_codeset()` with the character set obtained via
`locale_charset()`; Let's override that latter function to force the
encoding to UTF-8 on native Windows.

In Git for Windows' SDK, there is a `libcharset.h` and therefore we
define `HAVE_LIBCHARSET_H` in the MINGW-specific section in
`config.mak.uname`, therefore we need to add the override before that
conditionally-compiled code block.

Rather than simply defining `locale_charset()` to return the string
`"UTF-8"`, though, we are careful not to break `LC_ALL=C`: the
`ab/no-kwset` patch series, for example, needs to have a way to prevent
Git from expecting UTF-8-encoded input.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-03 14:03:32 -07:00

231 lines
5.7 KiB
C

/*
* Copyright (c) 2010 Ævar Arnfjörð Bjarmason
*/
#include "cache.h"
#include "exec-cmd.h"
#include "gettext.h"
#include "strbuf.h"
#include "utf8.h"
#include "config.h"
#ifndef NO_GETTEXT
# include <locale.h>
# include <libintl.h>
# ifdef GIT_WINDOWS_NATIVE
static const char *locale_charset(void)
{
const char *env = getenv("LC_ALL"), *dot;
if (!env || !*env)
env = getenv("LC_CTYPE");
if (!env || !*env)
env = getenv("LANG");
if (!env)
return "UTF-8";
dot = strchr(env, '.');
return !dot ? env : dot + 1;
}
# elif defined HAVE_LIBCHARSET_H
# include <libcharset.h>
# else
# include <langinfo.h>
# define locale_charset() nl_langinfo(CODESET)
# endif
#endif
static const char *charset;
/*
* Guess the user's preferred languages from the value in LANGUAGE environment
* variable and LC_MESSAGES locale category if NO_GETTEXT is not defined.
*
* The result can be a colon-separated list like "ko:ja:en".
*/
const char *get_preferred_languages(void)
{
const char *retval;
retval = getenv("LANGUAGE");
if (retval && *retval)
return retval;
#ifndef NO_GETTEXT
retval = setlocale(LC_MESSAGES, NULL);
if (retval && *retval &&
strcmp(retval, "C") &&
strcmp(retval, "POSIX"))
return retval;
#endif
return NULL;
}
int use_gettext_poison(void)
{
static int poison_requested = -1;
if (poison_requested == -1) {
const char *v = getenv("GIT_TEST_GETTEXT_POISON");
poison_requested = v && strlen(v) ? 1 : 0;
}
return poison_requested;
}
#ifndef NO_GETTEXT
static int test_vsnprintf(const char *fmt, ...)
{
char buf[26];
int ret;
va_list ap;
va_start(ap, fmt);
ret = vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
return ret;
}
static void init_gettext_charset(const char *domain)
{
/*
This trick arranges for messages to be emitted in the user's
requested encoding, but avoids setting LC_CTYPE from the
environment for the whole program.
This primarily done to avoid a bug in vsnprintf in the GNU C
Library [1]. which triggered a "your vsnprintf is broken" error
on Git's own repository when inspecting v0.99.6~1 under a UTF-8
locale.
That commit contains a ISO-8859-1 encoded author name, which
the locale aware vsnprintf(3) won't interpolate in the format
argument, due to mismatch between the data encoding and the
locale.
Even if it wasn't for that bug we wouldn't want to use LC_CTYPE at
this point, because it'd require auditing all the code that uses C
functions whose semantics are modified by LC_CTYPE.
But only setting LC_MESSAGES as we do creates a problem, since
we declare the encoding of our PO files[2] the gettext
implementation will try to recode it to the user's locale, but
without LC_CTYPE it'll emit something like this on 'git init'
under the Icelandic locale:
Bj? til t?ma Git lind ? /hlagh/.git/
Gettext knows about the encoding of our PO file, but we haven't
told it about the user's encoding, so all the non-US-ASCII
characters get encoded to question marks.
But we're in luck! We can set LC_CTYPE from the environment
only while we call nl_langinfo and
bind_textdomain_codeset. That suffices to tell gettext what
encoding it should emit in, so it'll now say:
Bjó til tóma Git lind í /hlagh/.git/
And the equivalent ISO-8859-1 string will be emitted under a
ISO-8859-1 locale.
With this change way we get the advantages of setting LC_CTYPE
(talk to the user in his language/encoding), without the major
drawbacks (changed semantics for C functions we rely on).
However foreign functions using other message catalogs that
aren't using our neat trick will still have a problem, e.g. if
we have to call perror(3):
#include <stdio.h>
#include <locale.h>
#include <errno.h>
int main(void)
{
setlocale(LC_MESSAGES, "");
setlocale(LC_CTYPE, "C");
errno = ENODEV;
perror("test");
return 0;
}
Running that will give you a message with question marks:
$ LANGUAGE= LANG=de_DE.utf8 ./test
test: Kein passendes Ger?t gefunden
The vsnprintf bug has been fixed since glibc 2.17.
Then we could simply set LC_CTYPE from the environment, which would
make things like the external perror(3) messages work.
See t/t0203-gettext-setlocale-sanity.sh's "gettext.c" tests for
regression tests.
1. http://sourceware.org/bugzilla/show_bug.cgi?id=6530
2. E.g. "Content-Type: text/plain; charset=UTF-8\n" in po/is.po
*/
setlocale(LC_CTYPE, "");
charset = locale_charset();
bind_textdomain_codeset(domain, charset);
/* the string is taken from v0.99.6~1 */
if (test_vsnprintf("%.*s", 13, "David_K\345gedal") < 0)
setlocale(LC_CTYPE, "C");
}
void git_setup_gettext(void)
{
const char *podir = getenv(GIT_TEXT_DOMAIN_DIR_ENVIRONMENT);
char *p = NULL;
if (!podir)
podir = p = system_path(GIT_LOCALE_PATH);
use_gettext_poison(); /* getenv() reentrancy paranoia */
if (!is_directory(podir)) {
free(p);
return;
}
bindtextdomain("git", podir);
setlocale(LC_MESSAGES, "");
setlocale(LC_TIME, "");
init_gettext_charset("git");
textdomain("git");
free(p);
}
/* return the number of columns of string 's' in current locale */
int gettext_width(const char *s)
{
static int is_utf8 = -1;
if (is_utf8 == -1)
is_utf8 = is_utf8_locale();
return is_utf8 ? utf8_strwidth(s) : strlen(s);
}
#endif
int is_utf8_locale(void)
{
#ifdef NO_GETTEXT
if (!charset) {
const char *env = getenv("LC_ALL");
if (!env || !*env)
env = getenv("LC_CTYPE");
if (!env || !*env)
env = getenv("LANG");
if (!env)
env = "";
if (strchr(env, '.'))
env = strchr(env, '.') + 1;
charset = xstrdup(env);
}
#endif
return is_encoding_utf8(charset);
}