git/gettext.c
Ævar Arnfjörð Bjarmason 6cdccfce1e i18n: make GETTEXT_POISON a runtime option
Change the GETTEXT_POISON compile-time + runtime GIT_GETTEXT_POISON
test parameter to only be a GIT_TEST_GETTEXT_POISON=<non-empty?>
runtime parameter, to be consistent with other parameters documented
in "Running tests with special setups" in t/README.

When I added GETTEXT_POISON in bb946bba76 ("i18n: add GETTEXT_POISON
to simulate unfriendly translator", 2011-02-22) I was concerned with
ensuring that the _() function would get constant folded if NO_GETTEXT
was defined, and likewise that GETTEXT_POISON would be compiled out
unless it was defined.

But as the benchmark in my [1] shows doing a one-off runtime
getenv("GIT_TEST_[...]") is trivial, and since GETTEXT_POISON was
originally added the GIT_TEST_* env variables have become the common
idiom for turning on special test setups.

So change GETTEXT_POISON to work the same way. Now the
GETTEXT_POISON=YesPlease compile-time option is gone, and running the
tests with GIT_TEST_GETTEXT_POISON=[YesPlease|] can be toggled on/off
without recompiling.

This allows for conditionally amending tests to test with/without
poison, similar to what 859fdc0c3c ("commit-graph: define
GIT_TEST_COMMIT_GRAPH", 2018-08-29) did for GIT_TEST_COMMIT_GRAPH. Do
some of that, now we e.g. always run the t0205-gettext-poison.sh test.

I did enough there to remove the GETTEXT_POISON prerequisite, but its
inverse C_LOCALE_OUTPUT is still around, and surely some tests using
it can be converted to e.g. always set GIT_TEST_GETTEXT_POISON=.

Notes on the implementation:

 * We still compile a dedicated GETTEXT_POISON build in Travis
   CI. Perhaps this should be revisited and integrated into the
   "linux-gcc" build, see ae59a4e44f ("travis: run tests with
   GIT_TEST_SPLIT_INDEX", 2018-01-07) for prior art in that area. Then
   again maybe not, see [2].

 * We now skip a test in t0000-basic.sh under
   GIT_TEST_GETTEXT_POISON=YesPlease that wasn't skipped before. This
   test relies on C locale output, but due to an edge case in how the
   previous implementation of GETTEXT_POISON worked (reading it from
   GIT-BUILD-OPTIONS) wasn't enabling poison correctly. Now it does,
   and needs to be skipped.

 * The getenv() function is not reentrant, so out of paranoia about
   code of the form:

       printf(_("%s"), getenv("some-env"));

   call use_gettext_poison() in our early setup in git_setup_gettext()
   so we populate the "poison_requested" variable in a codepath that's
   won't suffer from that race condition.

 * We error out in the Makefile if you're still saying
   GETTEXT_POISON=YesPlease to prompt users to change their
   invocation.

 * We should not print out poisoned messages during the test
   initialization itself to keep it more readable, so the test library
   hides the variable if set in $GIT_TEST_GETTEXT_POISON_ORIG during
   setup. See [3].

See also [4] for more on the motivation behind this patch, and the
history of the GETTEXT_POISON facility.

1. https://public-inbox.org/git/871s8gd32p.fsf@evledraar.gmail.com/
2. https://public-inbox.org/git/20181102163725.GY30222@szeder.dev/
3. https://public-inbox.org/git/20181022202241.18629-2-szeder.dev@gmail.com/
4. https://public-inbox.org/git/878t2pd6yu.fsf@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-09 11:25:19 +09:00

213 lines
5.4 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 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);
}