Fix worktree creation handling

src/lib.rs

@@ -474,15 +474,16 @@ pub fn add_worktree(
 
     let config = repo::read_worktree_root_config(directory)?;
 
-    let path = match subdirectory {
-        Some(dir) => dir.join(name),
-        None => Path::new(name).to_path_buf(),
-    };
 
-    if repo.find_worktree(&path).is_ok() {
+    if repo.find_worktree(&name).is_ok() {
         return Err(format!("Worktree {} already exists", &name));
     }
 
+    let path = match subdirectory {
+        Some(dir) => directory.join(dir).join(name),
+        None => directory.join(Path::new(name).to_path_buf()),
+    };
+
     let mut remote_branch_exists = false;
 
     let default_checkout = || repo.default_branch()?.to_commit();