Merge branch 'rs/nth-switch-code-simplification'
[git/git.git] / gettext.c
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1/*
2 * Copyright (c) 2010 Ævar Arnfjörð Bjarmason
3 */
4
226c0ddd 5#include "cache.h"
92034a9c 6#include "exec-cmd.h"
30955229 7#include "gettext.h"
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8#include "strbuf.h"
9#include "utf8.h"
6cdccfce 10#include "config.h"
30955229 11
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12#ifndef NO_GETTEXT
13# include <locale.h>
14# include <libintl.h>
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15# ifdef GIT_WINDOWS_NATIVE
16
17static const char *locale_charset(void)
18{
19 const char *env = getenv("LC_ALL"), *dot;
20
21 if (!env || !*env)
22 env = getenv("LC_CTYPE");
23 if (!env || !*env)
24 env = getenv("LANG");
25
26 if (!env)
27 return "UTF-8";
28
29 dot = strchr(env, '.');
30 return !dot ? env : dot + 1;
31}
32
33# elif defined HAVE_LIBCHARSET_H
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34# include <libcharset.h>
35# else
36# include <langinfo.h>
37# define locale_charset() nl_langinfo(CODESET)
38# endif
39#endif
40
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41static const char *charset;
42
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43/*
44 * Guess the user's preferred languages from the value in LANGUAGE environment
45 * variable and LC_MESSAGES locale category if NO_GETTEXT is not defined.
46 *
47 * The result can be a colon-separated list like "ko:ja:en".
48 */
49const char *get_preferred_languages(void)
50{
51 const char *retval;
52
53 retval = getenv("LANGUAGE");
54 if (retval && *retval)
55 return retval;
56
57#ifndef NO_GETTEXT
58 retval = setlocale(LC_MESSAGES, NULL);
59 if (retval && *retval &&
60 strcmp(retval, "C") &&
61 strcmp(retval, "POSIX"))
62 return retval;
63#endif
64
65 return NULL;
66}
67
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68int use_gettext_poison(void)
69{
70 static int poison_requested = -1;
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71 if (poison_requested == -1)
72 poison_requested = git_env_bool("GIT_TEST_GETTEXT_POISON", 0);
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73 return poison_requested;
74}
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75
76#ifndef NO_GETTEXT
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77static int test_vsnprintf(const char *fmt, ...)
78{
79 char buf[26];
80 int ret;
81 va_list ap;
82 va_start(ap, fmt);
83 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
84 va_end(ap);
85 return ret;
86}
87
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88static void init_gettext_charset(const char *domain)
89{
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90 /*
91 This trick arranges for messages to be emitted in the user's
92 requested encoding, but avoids setting LC_CTYPE from the
93 environment for the whole program.
94
95 This primarily done to avoid a bug in vsnprintf in the GNU C
96 Library [1]. which triggered a "your vsnprintf is broken" error
97 on Git's own repository when inspecting v0.99.6~1 under a UTF-8
98 locale.
99
100 That commit contains a ISO-8859-1 encoded author name, which
101 the locale aware vsnprintf(3) won't interpolate in the format
102 argument, due to mismatch between the data encoding and the
103 locale.
104
105 Even if it wasn't for that bug we wouldn't want to use LC_CTYPE at
106 this point, because it'd require auditing all the code that uses C
107 functions whose semantics are modified by LC_CTYPE.
108
109 But only setting LC_MESSAGES as we do creates a problem, since
110 we declare the encoding of our PO files[2] the gettext
111 implementation will try to recode it to the user's locale, but
112 without LC_CTYPE it'll emit something like this on 'git init'
113 under the Icelandic locale:
114
115 Bj? til t?ma Git lind ? /hlagh/.git/
116
117 Gettext knows about the encoding of our PO file, but we haven't
118 told it about the user's encoding, so all the non-US-ASCII
119 characters get encoded to question marks.
120
121 But we're in luck! We can set LC_CTYPE from the environment
122 only while we call nl_langinfo and
123 bind_textdomain_codeset. That suffices to tell gettext what
124 encoding it should emit in, so it'll now say:
125
126 Bjó til tóma Git lind í /hlagh/.git/
127
128 And the equivalent ISO-8859-1 string will be emitted under a
129 ISO-8859-1 locale.
130
131 With this change way we get the advantages of setting LC_CTYPE
132 (talk to the user in his language/encoding), without the major
133 drawbacks (changed semantics for C functions we rely on).
134
135 However foreign functions using other message catalogs that
136 aren't using our neat trick will still have a problem, e.g. if
137 we have to call perror(3):
138
139 #include <stdio.h>
140 #include <locale.h>
141 #include <errno.h>
142
143 int main(void)
144 {
145 setlocale(LC_MESSAGES, "");
146 setlocale(LC_CTYPE, "C");
147 errno = ENODEV;
148 perror("test");
149 return 0;
150 }
151
152 Running that will give you a message with question marks:
153
154 $ LANGUAGE= LANG=de_DE.utf8 ./test
155 test: Kein passendes Ger?t gefunden
156
9c0495d2 157 The vsnprintf bug has been fixed since glibc 2.17.
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158
159 Then we could simply set LC_CTYPE from the environment, which would
160 make things like the external perror(3) messages work.
161
162 See t/t0203-gettext-setlocale-sanity.sh's "gettext.c" tests for
163 regression tests.
164
165 1. http://sourceware.org/bugzilla/show_bug.cgi?id=6530
166 2. E.g. "Content-Type: text/plain; charset=UTF-8\n" in po/is.po
167 */
168 setlocale(LC_CTYPE, "");
169 charset = locale_charset();
170 bind_textdomain_codeset(domain, charset);
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171 /* the string is taken from v0.99.6~1 */
172 if (test_vsnprintf("%.*s", 13, "David_K\345gedal") < 0)
173 setlocale(LC_CTYPE, "C");
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174}
175
176void git_setup_gettext(void)
177{
226c0ddd 178 const char *podir = getenv(GIT_TEXT_DOMAIN_DIR_ENVIRONMENT);
0210231b 179 char *p = NULL;
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180
181 if (!podir)
0210231b 182 podir = p = system_path(GIT_LOCALE_PATH);
226c0ddd 183
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184 use_gettext_poison(); /* getenv() reentrancy paranoia */
185
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186 if (!is_directory(podir)) {
187 free(p);
cc5e1bf9 188 return;
0210231b 189 }
226c0ddd 190
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191 bindtextdomain("git", podir);
192 setlocale(LC_MESSAGES, "");
aa1462cc 193 setlocale(LC_TIME, "");
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194 init_gettext_charset("git");
195 textdomain("git");
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196
197 free(p);
5e9637c6 198}
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199
200/* return the number of columns of string 's' in current locale */
201int gettext_width(const char *s)
202{
203 static int is_utf8 = -1;
204 if (is_utf8 == -1)
e8c16726 205 is_utf8 = is_utf8_locale();
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206
207 return is_utf8 ? utf8_strwidth(s) : strlen(s);
208}
5e9637c6 209#endif
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210
211int is_utf8_locale(void)
212{
213#ifdef NO_GETTEXT
214 if (!charset) {
215 const char *env = getenv("LC_ALL");
216 if (!env || !*env)
217 env = getenv("LC_CTYPE");
218 if (!env || !*env)
219 env = getenv("LANG");
220 if (!env)
221 env = "";
222 if (strchr(env, '.'))
223 env = strchr(env, '.') + 1;
224 charset = xstrdup(env);
225 }
226#endif
227 return is_encoding_utf8(charset);
228}