git-multimail: update to release 1.2.0
[git.git] / gettext.c
bloba268a2c52c0ed444b073d0411ca0dcc3f210ef51
1 /*
2 * Copyright (c) 2010 Ævar Arnfjörð Bjarmason
3 */
5 #include "git-compat-util.h"
6 #include "gettext.h"
7 #include "strbuf.h"
8 #include "utf8.h"
10 #ifndef NO_GETTEXT
11 # include <locale.h>
12 # include <libintl.h>
13 # ifdef HAVE_LIBCHARSET_H
14 # include <libcharset.h>
15 # else
16 # include <langinfo.h>
17 # define locale_charset() nl_langinfo(CODESET)
18 # endif
19 #endif
22 * Guess the user's preferred languages from the value in LANGUAGE environment
23 * variable and LC_MESSAGES locale category if NO_GETTEXT is not defined.
25 * The result can be a colon-separated list like "ko:ja:en".
27 const char *get_preferred_languages(void)
29 const char *retval;
31 retval = getenv("LANGUAGE");
32 if (retval && *retval)
33 return retval;
35 #ifndef NO_GETTEXT
36 retval = setlocale(LC_MESSAGES, NULL);
37 if (retval && *retval &&
38 strcmp(retval, "C") &&
39 strcmp(retval, "POSIX"))
40 return retval;
41 #endif
43 return NULL;
46 #ifdef GETTEXT_POISON
47 int use_gettext_poison(void)
49 static int poison_requested = -1;
50 if (poison_requested == -1)
51 poison_requested = getenv("GIT_GETTEXT_POISON") ? 1 : 0;
52 return poison_requested;
54 #endif
56 #ifndef NO_GETTEXT
57 static int test_vsnprintf(const char *fmt, ...)
59 char buf[26];
60 int ret;
61 va_list ap;
62 va_start(ap, fmt);
63 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
64 va_end(ap);
65 return ret;
68 static const char *charset;
69 static void init_gettext_charset(const char *domain)
72 This trick arranges for messages to be emitted in the user's
73 requested encoding, but avoids setting LC_CTYPE from the
74 environment for the whole program.
76 This primarily done to avoid a bug in vsnprintf in the GNU C
77 Library [1]. which triggered a "your vsnprintf is broken" error
78 on Git's own repository when inspecting v0.99.6~1 under a UTF-8
79 locale.
81 That commit contains a ISO-8859-1 encoded author name, which
82 the locale aware vsnprintf(3) won't interpolate in the format
83 argument, due to mismatch between the data encoding and the
84 locale.
86 Even if it wasn't for that bug we wouldn't want to use LC_CTYPE at
87 this point, because it'd require auditing all the code that uses C
88 functions whose semantics are modified by LC_CTYPE.
90 But only setting LC_MESSAGES as we do creates a problem, since
91 we declare the encoding of our PO files[2] the gettext
92 implementation will try to recode it to the user's locale, but
93 without LC_CTYPE it'll emit something like this on 'git init'
94 under the Icelandic locale:
96 Bj? til t?ma Git lind ? /hlagh/.git/
98 Gettext knows about the encoding of our PO file, but we haven't
99 told it about the user's encoding, so all the non-US-ASCII
100 characters get encoded to question marks.
102 But we're in luck! We can set LC_CTYPE from the environment
103 only while we call nl_langinfo and
104 bind_textdomain_codeset. That suffices to tell gettext what
105 encoding it should emit in, so it'll now say:
107 Bjó til tóma Git lind í /hlagh/.git/
109 And the equivalent ISO-8859-1 string will be emitted under a
110 ISO-8859-1 locale.
112 With this change way we get the advantages of setting LC_CTYPE
113 (talk to the user in his language/encoding), without the major
114 drawbacks (changed semantics for C functions we rely on).
116 However foreign functions using other message catalogs that
117 aren't using our neat trick will still have a problem, e.g. if
118 we have to call perror(3):
120 #include <stdio.h>
121 #include <locale.h>
122 #include <errno.h>
124 int main(void)
126 setlocale(LC_MESSAGES, "");
127 setlocale(LC_CTYPE, "C");
128 errno = ENODEV;
129 perror("test");
130 return 0;
133 Running that will give you a message with question marks:
135 $ LANGUAGE= LANG=de_DE.utf8 ./test
136 test: Kein passendes Ger?t gefunden
138 The vsnprintf bug has been fixed since glibc 2.17.
140 Then we could simply set LC_CTYPE from the environment, which would
141 make things like the external perror(3) messages work.
143 See t/t0203-gettext-setlocale-sanity.sh's "gettext.c" tests for
144 regression tests.
146 1. http://sourceware.org/bugzilla/show_bug.cgi?id=6530
147 2. E.g. "Content-Type: text/plain; charset=UTF-8\n" in po/is.po
149 setlocale(LC_CTYPE, "");
150 charset = locale_charset();
151 bind_textdomain_codeset(domain, charset);
152 /* the string is taken from v0.99.6~1 */
153 if (test_vsnprintf("%.*s", 13, "David_K\345gedal") < 0)
154 setlocale(LC_CTYPE, "C");
157 void git_setup_gettext(void)
159 const char *podir = getenv("GIT_TEXTDOMAINDIR");
161 if (!podir)
162 podir = GIT_LOCALE_PATH;
163 bindtextdomain("git", podir);
164 setlocale(LC_MESSAGES, "");
165 setlocale(LC_TIME, "");
166 init_gettext_charset("git");
167 textdomain("git");
170 /* return the number of columns of string 's' in current locale */
171 int gettext_width(const char *s)
173 static int is_utf8 = -1;
174 if (is_utf8 == -1)
175 is_utf8 = !strcmp(charset, "UTF-8");
177 return is_utf8 ? utf8_strwidth(s) : strlen(s);
179 #endif