classes/image: implement generic locale package installation

Let each package-specific rootfs implementation provide basic functions
to query the existence of a package and install a list of packages and
then have a generic install function so this logic is in one place.

Note: unlike previous versions of this code in OE-Core this uses the
IMAGE_LINGUAS variable and not IMAGE_LOCALES - note that IMAGE_LINGUAS
was what was used in OE-Classic and it is already used in OE-Core in
order to install locale-base-*. This will mean that if IMAGE_LINGUAS is
left at the default you will now get more packages installed. If you
don't want these language support packages then you should set
IMAGE_LINGUAS explicitly.

This restores locale installation to the same state as OE-Classic, only
we now support all the packaging backends.

(From OE-Core rev: c0fc36f8629a6abb9a7b542df8a2857526547a31)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/image.bbclass

@@ -255,6 +255,43 @@ multilib_sanity_check() {
   echo $@ | python ${MULTILIB_CHECK_FILE}
 }
 
+get_split_linguas() {
+    for translation in ${IMAGE_LINGUAS}; do
+        translation_split=$(echo ${translation} | awk -F '-' '{print $1}')
+        echo ${translation}
+        echo ${translation_split}
+    done | sort | uniq
+}
+
+rootfs_install_all_locales() {
+    # Generate list of installed packages for which additional locale packages might be available
+    INSTALLED_PACKAGES=`list_installed_packages | egrep -v -- "(-locale-|^locale-base-|-dev$|-doc$|^kernel|^glibc|^ttf|^task|^perl|^python)"`
+
+    # Generate a list of locale packages that exist
+    SPLIT_LINGUAS=`get_split_linguas`
+    PACKAGES_TO_INSTALL=""
+    for lang in $SPLIT_LINGUAS; do
+        for pkg in $INSTALLED_PACKAGES; do
+            existing_pkg=`rootfs_check_package_exists $pkg-locale-$lang`
+            if [ "$existing_pkg" != "" ]; then
+                PACKAGES_TO_INSTALL="$PACKAGES_TO_INSTALL $existing_pkg"
+            fi
+        done
+    done
+
+    # Install the packages, if any
+    if [ "$PACKAGES_TO_INSTALL" != "" ]; then
+        rootfs_install_packages $PACKAGES_TO_INSTALL
+    fi
+
+    # Workaround for broken shell function dependencies
+    if false ; then
+        get_split_linguas
+        list_installed_packages
+        rootfs_check_package_exists
+    fi
+}
+
 # set '*' as the root password so the images
 # can decide if they want it or not
 zap_root_password () {