repo-add: show better error when path to repo does not exist

Previously, the error message when trying to add to a repo where a
parent directory didn't exist was:

==> ERROR: Failed to acquire lockfile: /path/to/noexist/repo.tar.gz.lck

This sucks. Make an explicit check to ensure that the path to the repo
really does exist, and throw a meaningful error message when it can't be
found.

Dan: reuse an existing (translated) error message.

Signed-off-by: Dave Reisner <d@falconindy.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

scripts/repo-add.sh.in

@@ -382,6 +382,12 @@ db_remove_entry() {
 
 check_repo_db()
 {
+	# ensure the path to the DB exists
+	if [[ ! -d "${LOCKFILE%/*}" ]]; then
+		error "$(gettext "%s does not exist or is not a directory.")" "${LOCKFILE%/*}"
+		exit 1
+	fi
+
 	# check lock file
 	if ( set -o noclobber; echo "$$" > "$LOCKFILE") 2> /dev/null; then
 		CLEAN_LOCK=1