Windows: Workaround a UTF-8 issue in Gettext's libintl_setlocale()

See the comment. In this package, locale is set at program startup and
not changed later, so the point (2) in the comment isn't a problem.

Fixes: 46ee0061629fb075d61d83839e14dd193337af59
(cherry picked from commit b40e3321a7fb9dfdf8ffb30e7e0788c2f0abc941)

diff --git a/src/common/tuklib_gettext.h b/src/common/tuklib_gettext.h
index 3ef5cb7292b59b57756d4abfc7dcec4fb808b005..008cf491eedd905c614f71f220aad570af3add02 100644 (file)
--- a/src/common/tuklib_gettext.h
+++ b/src/common/tuklib_gettext.h
@@ -24,6 +24,57 @@
 #endif
 
 #if TUKLIB_GETTEXT
+#      if defined(_WIN32) && !defined(__CYGWIN__)
+               // <libintl.h> from gettext-runtime redirects setlocale()
+               // to libintl_setlocale(). As of gettext 0.22.5 (and probably
+               // 0.23), libintl_setlocale(LC_ALL, "") doesn't set the locale
+               // to UTF-8 if UTF-8 code page has been set in the application
+               // manifest. For example, one may get "fi_FI" when native
+               // setlocale() would result in "Finnish_Finland.utf8". The
+               // lack of ".utf8" (or equivalent) suffix results in garbled
+               // non-ASCII chars in translatated messages and also affects
+               // functions like mbrtowc() which depend on LC_CTYPE.
+               //
+               // Workaround the problem by not using libintl_setlocale()
+               // for now. Notes:
+               //
+               // (1) libintl_setlocale() reads LC_* environment variables
+               //     but native setlocale() doesn't. The loss of this
+               //     feature doesn't matter too much because, on Windows,
+               //     libintl still reads the env vars LANGUAGE, LC_ALL,
+               //     LC_MESSAGES, and LANG when translating messages in
+               //     the LC_MESSAGES category (other categories are very
+               //     rarely used for translations). As of Gettext commit
+               //     e18edc579 and Gnulib commit 9e301775ff:
+               //
+               //     libintl_gettext()
+               //      `-- libintl_dcgettext()
+               //           `-- libintl_dcigettext()
+               //                `-- guess_category_value()
+               //                     |-- gl_locale_name_posix()
+               //                     |    `-- gl_locale_name_posix_unsafe()
+               //                     |         `-- gl_locale_name_environ()
+               //                     |              |-- getenv("LC_ALL")
+               //                     |              |-- getenv("LC_MESSAGES")
+               //                     |              `-- getenv("LANG")
+               //                     `-- getenv("LANGUAGE")
+               //
+               // (2) If locale is changed, libintl_setlocale() marks cached
+               //     translations as invalid. bindtextdomain(), which we
+               //     call immediately after setlocale(), does the same
+               //     invalidation too. Thus it doesn't matter in the
+               //     tuklib_gettext_init() macro. It could matter if the
+               //     application calls setlocale() elsewhere though (but
+               //     then it's not guaranteed that such code even includes
+               //     <libint.h> in addition to <locale.h>).
+               //
+               // This macro is checked by <libintl.h> since Gettext 0.18.2
+               // (2012-12-08). When this is defined, setlocale() isn't
+               // overridden.
+               //
+               // FIXME: Remove this hack when it's no longer needed.
+#              define GNULIB_defined_setlocale 1
+#      endif
 #      include <libintl.h>
 #      define tuklib_gettext_init(package, localedir) \
                do { \