gettext.con commit Merge branch 'ma/fast-export-skip-merge-fix' (ad3207e)
   1/*
   2 * Copyright (c) 2010 Ævar Arnfjörð Bjarmason
   3 */
   4
   5#include "cache.h"
   6#include "exec-cmd.h"
   7#include "gettext.h"
   8#include "strbuf.h"
   9#include "utf8.h"
  10
  11#ifndef NO_GETTEXT
  12#       include <locale.h>
  13#       include <libintl.h>
  14#       ifdef HAVE_LIBCHARSET_H
  15#               include <libcharset.h>
  16#       else
  17#               include <langinfo.h>
  18#               define locale_charset() nl_langinfo(CODESET)
  19#       endif
  20#endif
  21
  22static const char *charset;
  23
  24/*
  25 * Guess the user's preferred languages from the value in LANGUAGE environment
  26 * variable and LC_MESSAGES locale category if NO_GETTEXT is not defined.
  27 *
  28 * The result can be a colon-separated list like "ko:ja:en".
  29 */
  30const char *get_preferred_languages(void)
  31{
  32        const char *retval;
  33
  34        retval = getenv("LANGUAGE");
  35        if (retval && *retval)
  36                return retval;
  37
  38#ifndef NO_GETTEXT
  39        retval = setlocale(LC_MESSAGES, NULL);
  40        if (retval && *retval &&
  41                strcmp(retval, "C") &&
  42                strcmp(retval, "POSIX"))
  43                return retval;
  44#endif
  45
  46        return NULL;
  47}
  48
  49#ifdef GETTEXT_POISON
  50int use_gettext_poison(void)
  51{
  52        static int poison_requested = -1;
  53        if (poison_requested == -1)
  54                poison_requested = getenv("GIT_GETTEXT_POISON") ? 1 : 0;
  55        return poison_requested;
  56}
  57#endif
  58
  59#ifndef NO_GETTEXT
  60static int test_vsnprintf(const char *fmt, ...)
  61{
  62        char buf[26];
  63        int ret;
  64        va_list ap;
  65        va_start(ap, fmt);
  66        ret = vsnprintf(buf, sizeof(buf), fmt, ap);
  67        va_end(ap);
  68        return ret;
  69}
  70
  71static void init_gettext_charset(const char *domain)
  72{
  73        /*
  74           This trick arranges for messages to be emitted in the user's
  75           requested encoding, but avoids setting LC_CTYPE from the
  76           environment for the whole program.
  77
  78           This primarily done to avoid a bug in vsnprintf in the GNU C
  79           Library [1]. which triggered a "your vsnprintf is broken" error
  80           on Git's own repository when inspecting v0.99.6~1 under a UTF-8
  81           locale.
  82
  83           That commit contains a ISO-8859-1 encoded author name, which
  84           the locale aware vsnprintf(3) won't interpolate in the format
  85           argument, due to mismatch between the data encoding and the
  86           locale.
  87
  88           Even if it wasn't for that bug we wouldn't want to use LC_CTYPE at
  89           this point, because it'd require auditing all the code that uses C
  90           functions whose semantics are modified by LC_CTYPE.
  91
  92           But only setting LC_MESSAGES as we do creates a problem, since
  93           we declare the encoding of our PO files[2] the gettext
  94           implementation will try to recode it to the user's locale, but
  95           without LC_CTYPE it'll emit something like this on 'git init'
  96           under the Icelandic locale:
  97
  98               Bj? til t?ma Git lind ? /hlagh/.git/
  99
 100           Gettext knows about the encoding of our PO file, but we haven't
 101           told it about the user's encoding, so all the non-US-ASCII
 102           characters get encoded to question marks.
 103
 104           But we're in luck! We can set LC_CTYPE from the environment
 105           only while we call nl_langinfo and
 106           bind_textdomain_codeset. That suffices to tell gettext what
 107           encoding it should emit in, so it'll now say:
 108
 109               Bjó til tóma Git lind í /hlagh/.git/
 110
 111           And the equivalent ISO-8859-1 string will be emitted under a
 112           ISO-8859-1 locale.
 113
 114           With this change way we get the advantages of setting LC_CTYPE
 115           (talk to the user in his language/encoding), without the major
 116           drawbacks (changed semantics for C functions we rely on).
 117
 118           However foreign functions using other message catalogs that
 119           aren't using our neat trick will still have a problem, e.g. if
 120           we have to call perror(3):
 121
 122           #include <stdio.h>
 123           #include <locale.h>
 124           #include <errno.h>
 125
 126           int main(void)
 127           {
 128                   setlocale(LC_MESSAGES, "");
 129                   setlocale(LC_CTYPE, "C");
 130                   errno = ENODEV;
 131                   perror("test");
 132                   return 0;
 133           }
 134
 135           Running that will give you a message with question marks:
 136
 137           $ LANGUAGE= LANG=de_DE.utf8 ./test
 138           test: Kein passendes Ger?t gefunden
 139
 140           The vsnprintf bug has been fixed since glibc 2.17.
 141
 142           Then we could simply set LC_CTYPE from the environment, which would
 143           make things like the external perror(3) messages work.
 144
 145           See t/t0203-gettext-setlocale-sanity.sh's "gettext.c" tests for
 146           regression tests.
 147
 148           1. http://sourceware.org/bugzilla/show_bug.cgi?id=6530
 149           2. E.g. "Content-Type: text/plain; charset=UTF-8\n" in po/is.po
 150        */
 151        setlocale(LC_CTYPE, "");
 152        charset = locale_charset();
 153        bind_textdomain_codeset(domain, charset);
 154        /* the string is taken from v0.99.6~1 */
 155        if (test_vsnprintf("%.*s", 13, "David_K\345gedal") < 0)
 156                setlocale(LC_CTYPE, "C");
 157}
 158
 159void git_setup_gettext(void)
 160{
 161        const char *podir = getenv(GIT_TEXT_DOMAIN_DIR_ENVIRONMENT);
 162
 163        if (!podir)
 164                podir = system_path(GIT_LOCALE_PATH);
 165
 166        bindtextdomain("git", podir);
 167        setlocale(LC_MESSAGES, "");
 168        setlocale(LC_TIME, "");
 169        init_gettext_charset("git");
 170        textdomain("git");
 171}
 172
 173/* return the number of columns of string 's' in current locale */
 174int gettext_width(const char *s)
 175{
 176        static int is_utf8 = -1;
 177        if (is_utf8 == -1)
 178                is_utf8 = is_utf8_locale();
 179
 180        return is_utf8 ? utf8_strwidth(s) : strlen(s);
 181}
 182#endif
 183
 184int is_utf8_locale(void)
 185{
 186#ifdef NO_GETTEXT
 187        if (!charset) {
 188                const char *env = getenv("LC_ALL");
 189                if (!env || !*env)
 190                        env = getenv("LC_CTYPE");
 191                if (!env || !*env)
 192                        env = getenv("LANG");
 193                if (!env)
 194                        env = "";
 195                if (strchr(env, '.'))
 196                        env = strchr(env, '.') + 1;
 197                charset = xstrdup(env);
 198        }
 199#endif
 200        return is_encoding_utf8(charset);
 201}