gettext.c: remove/reword a mostly-useless comment

[thirdparty/git.git] / gettext.c

diff --git a/gettext.c b/gettext.c
index 35d2c1218db2e27a6ac07fbf3c1244987e3e3021..1b564216d03f6a7bb75fb4c867ad1b0e5cfbecd0 100644 (file)
--- a/gettext.c
+++ b/gettext.c
@@ -87,88 +87,24 @@ static int test_vsnprintf(const char *fmt, ...)
 
 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 */
+
+       /*
+        * Work around an old bug fixed in glibc 2.17 (released on
+        * 2012-12-24), at the cost of potentially making translated
+        * messages from external functions like perror() emitted in
+        * the wrong encoding.
+        *
+        * The bug affected e.g. git.git's own 7eb93c89651 ([PATCH]
+        * Simplify git script, 2005-09-07), which is the origin of
+        * the "David_K\345gedal" test string.
+        *
+        * See a much longer comment added to this file in 5e9637c6297
+        * (i18n: add infrastructure for translating Git with gettext,
+        * 2011-11-18) for more details.
+        */
        if (test_vsnprintf("%.*s", 13, "David_K\345gedal") < 0)
                setlocale(LC_CTYPE, "C");
 }