Hmm well I think that particular issue was in the original version you wrote, but now I see that I was wrong about the new version I suggested being equivalent if `$FEATURE_BRANCH` is empty.

I think a more complete test would be something like:
`if [ -n "$FEATURE_BRANCH" ] && echo "$FEATURE_BRANCH" | egrep -q "^$ISSUE_NUMBER[_-]|[_-]$ISSUE_NUMBER\$"; then`