grep/pcre: prepare locale-dependent tables for icase matching
[git/git.git] / gettext.c
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1/*
2 * Copyright (c) 2010 Ævar Arnfjörð Bjarmason
3 */
4
5#include "git-compat-util.h"
6#include "gettext.h"
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7#include "strbuf.h"
8#include "utf8.h"
30955229 9
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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
20
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21/*
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.
24 *
25 * The result can be a colon-separated list like "ko:ja:en".
26 */
27const char *get_preferred_languages(void)
28{
29 const char *retval;
30
31 retval = getenv("LANGUAGE");
32 if (retval && *retval)
33 return retval;
34
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
42
43 return NULL;
44}
45
5e9637c6 46#ifdef GETTEXT_POISON
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47int use_gettext_poison(void)
48{
49 static int poison_requested = -1;
50 if (poison_requested == -1)
51 poison_requested = getenv("GIT_GETTEXT_POISON") ? 1 : 0;
52 return poison_requested;
53}
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54#endif
55
56#ifndef NO_GETTEXT
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57static int test_vsnprintf(const char *fmt, ...)
58{
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;
66}
67
754395d3 68static const char *charset;
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69static void init_gettext_charset(const char *domain)
70{
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71 /*
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.
75
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.
80
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.
85
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.
89
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:
95
96 Bj? til t?ma Git lind ? /hlagh/.git/
97
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.
101
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:
106
107 Bjó til tóma Git lind í /hlagh/.git/
108
109 And the equivalent ISO-8859-1 string will be emitted under a
110 ISO-8859-1 locale.
111
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).
115
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):
119
120 #include <stdio.h>
121 #include <locale.h>
122 #include <errno.h>
123
124 int main(void)
125 {
126 setlocale(LC_MESSAGES, "");
127 setlocale(LC_CTYPE, "C");
128 errno = ENODEV;
129 perror("test");
130 return 0;
131 }
132
133 Running that will give you a message with question marks:
134
135 $ LANGUAGE= LANG=de_DE.utf8 ./test
136 test: Kein passendes Ger?t gefunden
137
9c0495d2 138 The vsnprintf bug has been fixed since glibc 2.17.
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139
140 Then we could simply set LC_CTYPE from the environment, which would
141 make things like the external perror(3) messages work.
142
143 See t/t0203-gettext-setlocale-sanity.sh's "gettext.c" tests for
144 regression tests.
145
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
148 */
149 setlocale(LC_CTYPE, "");
150 charset = locale_charset();
151 bind_textdomain_codeset(domain, charset);
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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");
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155}
156
157void git_setup_gettext(void)
158{
159 const char *podir = getenv("GIT_TEXTDOMAINDIR");
160
161 if (!podir)
162 podir = GIT_LOCALE_PATH;
163 bindtextdomain("git", podir);
164 setlocale(LC_MESSAGES, "");
aa1462cc 165 setlocale(LC_TIME, "");
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166 init_gettext_charset("git");
167 textdomain("git");
168}
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169
170/* return the number of columns of string 's' in current locale */
171int gettext_width(const char *s)
172{
173 static int is_utf8 = -1;
174 if (is_utf8 == -1)
175 is_utf8 = !strcmp(charset, "UTF-8");
176
177 return is_utf8 ? utf8_strwidth(s) : strlen(s);
178}
5e9637c6 179#endif