Show an error if a user tries to do git stree forget with a stree name

git-stree

@@ -143,10 +143,18 @@ function error
 # Command: `git stree forget`
 function forget_subtrees
 {
- for name in $(get_subtree_list simple); do
- rm_subtree "$name" && discreet "• Removed subtree '$name'"
- done
- yay 'Successfully removed all subtree definitions.'
+ if [ -z "${args[1]}" ]; then
+ for name in $(get_subtree_list simple); do
+ rm_subtree "$name" && discreet "• Removed subtree '$name'"
+ done
+ yay 'Successfully removed all subtree definitions.'
+ else
+ error false "This is not the command you're looking for.
+git stree forget removes all subtrees defined for this repository.
+You specified a specific subtree ($1) on the command line,
+so you probably want: git stree rm $1
+"
+ fi
 }
 
 # Helper: computes a backport branch name based on the passed CLI name.