firefox-i18n update-lang-list: use package name as argument

While we're at it, stop create bogus symlink firefox-18n/firefox-18n

The script always execute ln, if subpackages exists, ln will consider
it's a directory, thus making firefox-i18n-<lang>/firefox-i18n symlink.

srcpkgs/firefox-i18n/files/update-lang-list

@@ -1,4 +1,5 @@
 #!/bin/bash
+# Usage: $0 <firefox|firefox-esr>
 # Copyright (c) 2019 Danh Doan
 # All rights reserved.
 #
@@ -13,20 +14,27 @@
 # OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 # PERFORMANCE OF THIS SOFTWARE.
 
-version=$1
+pkg=${1:-firefox}
+tmpldir="$pkg-i18n"
 
-esr=""
-[[ $version =~ esr$ ]] && esr="-esr"
-
-tmpldir="firefox${esr}-i18n"
+case "${pkg}" in
+firefox-esr) esr=esr ;;
+firefox) : ;;
+*)
+	echo "Usage: $0 <firefox|firefox-esr>" >&2
+	exit 1
+	;;
+esac
 
 tmpoldfile="$(mktemp)"
 tmpnewfile="$(mktemp)"
 
 xoldlangexpr="^_languages="
 
+cd "$(xdistdir)/srcpkgs"
+source "${tmpldir}/template"
+
 xlistold() {
-	source "${tmpldir}/template"
 	for _lang in "${_languages[@]}"; do
 		_locale="${_lang%%\"*}"
 		[ $_locale ] && echo "$_locale"
@@ -34,6 +42,7 @@ xlistold() {
 }
 
 xlink () {
+	test -L "$tmpldir-$1" ||
 	ln -sf "$tmpldir" "$tmpldir-$1"
 }
 
@@ -51,7 +60,7 @@ xnewlang () {
 }
 
 xprocessnew() {
-	while read lang; do
+	while read -r lang; do
 		printf '%-7s\n' $lang >&3
 		xlink $lang
 		xnewlang $lang
@@ -59,18 +68,16 @@ xprocessnew() {
 }
 
 xcleanlang() {
-	while read lang; do
+	while read -r lang; do
 		padded=$(printf '%-7s' $lang)
 		sed -i "/'$padded\"/d" $tmpldir/template
 		unlink "$tmpldir-$lang" || true
 	done
 }
 
-cd $(xdistdir)/srcpkgs
-
 xlistold >| "$tmpoldfile"
 
-curl "https://ftp.mozilla.org/pub/firefox/releases/$1/linux-i686/xpi/" \
+curl "https://ftp.mozilla.org/pub/firefox/releases/$version$esr/linux-i686/xpi/" \
 	| grep -o 'xpi/[a-z]\+\(-[A-Z]\+\)\?' \
 	| cut -d/ -f2 \
 	| xprocessnew 3>$tmpnewfile