[PATCH v4] dracut: 10i18n: add support for custom locale definitions

[Guido Trentalancia <guido-D1bseh+SzQhuxeB9wqlrNw@public.gmane.org>]

Compile and install locale definitions using localedef from GNU libc or,
if locale definitions cannot be compiled but are available on the system
as split definitions, just install them.

The resulting locale definitions archive contains at most two different
locale definitions, therefore its size is relatively small.

This revised version fixes several issues in the initial patch (including
the possibility to build locale definitions). Thanks to Andrei Borzenkov
for reviewing the initial patch and providing useful suggestions.

Signed-off-by: Guido Trentalancia <guido-D1bseh+SzQhuxeB9wqlrNw@public.gmane.org>
---
 modules.d/10i18n/module-setup.sh |   20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

--- dracut-044-orig/modules.d/10i18n/module-setup.sh	2015-11-25 14:22:28.000000000 +0100
+++ dracut-044-10i18n-add-support-for-custom-locale-definitions/modules.d/10i18n/module-setup.sh	2016-04-16 22:09:43.667941277 +0200
@@ -212,6 +219,26 @@ install() {
             print_vars LC_ALL LANG >> ${initdir}${I18N_CONF}
         fi
 
+        [[ ${LC_ALL} || ${LANG} ]] && inst_dir /usr/lib/locale
+
+        # Check if we can compile locale definitions
+        command -v localedef > /dev/null && HAS_LOCALEDEF=true || HAS_LOCALEDEF=false
+        [[ -e /usr/share/i18n/locales/${LC_ALL} || -e /usr/share/i18n/locales/${LANG} ]] && HAS_LOCALE_SOURCES=true || HAS_LOCALE_SOURCES=false
+        [[ ${HAS_LOCALEDEF} == true && ${HAS_LOCALE_SOURCES} == true ]] && CAN_BUILD_LOCALE=true || CAN_BUILD_LOCALE=false
+
+        # Generate locale definitions for LC_ALL
+        [ ${LC_ALL} ] && LC_ALL_LOCALE=`echo ${LC_ALL} | awk -F. '{ print $1 }'` && LC_ALL_CHARMAP=`echo ${LC_ALL} | awk -F. '{ print $2 }'`
+        [[ ${LC_ALL} && ${LC_ALL_LOCALE} && ${LC_ALL_CHARMAP} ]] && [ ${CAN_BUILD_LOCALE} == true ] && [ -e /usr/share/i18n/locales/${LC_ALL} ] && localedef --prefix="${initdir}" -i ${LC_ALL_LOCALE} -f ${LC_ALL_CHARMAP} ${LC_ALL}
+
+        # Generate locale definitions for LANG
+        [ ${LANG} ] && [ ${LANG} != ${LC_ALL} ] && LANG_LOCALE=`echo ${LANG} | awk -F. '{ print $1 }'` && LANG_CHARMAP=`echo ${LANG} | awk -F. '{ print $2 }'`
+        [[ ${LANG} && ${LANG_LOCALE} && ${LANG_CHARMAP} ]] && [ ${CAN_BUILD_LOCALE} == true ] && [ -e /usr/share/i18n/locales/${LANG} ] && localedef --prefix="${initdir}" -i ${LANG_LOCALE} -f ${LANG_CHARMAP} ${LANG}
+
+        # If locale definitions cannot be built, but compiled split definitions are
+        # available, then copy them over
+        [ ${LC_ALL} ] && [ ${CAN_BUILD_LOCALE} == false ] && [ -d /usr/lib/locale/${LC_ALL} ] && cp -prfL -t "${initdir}/usr/lib/locale/" /usr/lib/locale/${LC_ALL}
+        [ ${LANG} ] && [ ${LANG} != ${LC_ALL} ] && [ ${CAN_BUILD_LOCALE} == false ] && [ -d /usr/lib/locale/${LANG} ] && cp -prfL -t "${initdir}/usr/lib/locale/" /usr/lib/locale/${LANG}
+
         if dracut_module_included "systemd" && [[ -f ${VCONFIG_CONF} ]]; then
             inst_simple ${VCONFIG_CONF}
         else