Assure that valid issue is specified

diff --git a/tag-add b/tag-add
index e6bf85d0f847f776a8431c6a89714808918676fe1d3fac06ab3522d72a364f55..e26df324b2d20cd831a8c5bb8abcf4c3143e3a6c53239ef6774a4d0700aa389c 100755 (executable)
--- a/tag-add
+++ b/tag-add
@@ -9,6 +9,7 @@ usage() {
 
 [[ -n $1 ]] || usage
 issue=${1#issues/}
+[[ -d issues/$issue ]] || die Unknown issue
 shift
 for tag ($@) {
     tag=tags/$tag:t