fix(engine): preset imports number duplicate names in linear time

crates/engine/src/tests/cmdsplit.rs

@@ -66,6 +66,28 @@ fn unique_name_appends_the_first_free_number() {
     assert_eq!(unique_name("A 2", |n| taken.contains(&n)), "A 2 2");
 }
 
+#[test]
+fn unique_name_from_counts_on_for_a_run_of_one_name() {
+    let mut taken = vec!["A".to_string(), "a 3".to_string()];
+    let mut next = std::collections::HashMap::new();
+    for want in ["A 2", "A 4", "A 5"] {
+        let is_taken = |n: &str| taken.iter().any(|t| t.eq_ignore_ascii_case(n));
+        let n = crate::cmd::unique_name_from("A", &mut next, is_taken);
+        assert_eq!(n, want);
+        taken.push(n);
+    }
+    assert_eq!(crate::cmd::unique_name_from("B", &mut next, |_| false), "B");
+}
+
+#[test]
+fn a_presets_file_with_too_many_presets_is_refused() {
+    let mut s = Session::new();
+    let presets: Vec<_> = (0..=crate::cmd::MAX_IMPORTED_PRESETS).map(|_| serde_json::json!({"name": "P"})).collect();
+    let file = serde_json::json!({"format": crate::cmd::printpresets::PRESET_FORMAT, "presets": presets}).to_string();
+    let e = s.execute("print.presets.import", &serde_json::json!({"data": file})).unwrap_err().to_string();
+    assert!(e.contains("over"), "{e}");
+}
+
 #[test]
 fn leaf_targets_expand_groups_and_stop_at_compound_paths() {
     let mut s = session();