1 files changed, 228 insertions, 0 deletions
diff --git a/gettext.c b/gettext.c
new file mode 100644
index 000000000000..35d2c1218db2
--- /dev/null
+++ b/gettext.c
@@ -0,0 +1,228 @@
+/*
+ * 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 GIT_WINDOWS_NATIVE
+
+static const char *locale_charset(void)
+{
+	const char *env = getenv("LC_ALL"), *dot;
+
+	if (!env || !*env)
+		env = getenv("LC_CTYPE");
+	if (!env || !*env)
+		env = getenv("LANG");
+
+	if (!env)
+		return "UTF-8";
+
+	dot = strchr(env, '.');
+	return !dot ? env : dot + 1;
+}
+
+#	elif defined 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)
+		poison_requested = git_env_bool("GIT_TEST_GETTEXT_POISON", 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);
+}