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

crates/engine/src/cmd.rs

@@ -611,6 +611,26 @@ pub(crate) fn unique_name(base: &str, taken: impl Fn(&str) -> bool) -> String {
     (2..).map(|i| format!("{base} {i}")).find(|n| !taken(n)).unwrap_or_else(|| base.to_string())
 }
 
+/// [`unique_name`] for names given one after another (an import): `next` keeps, per base (in
+/// any case), the number after the last one tried, so a run of one name doesn't count up from 2
+/// again for each copy. Names only become taken meanwhile, so the result is the same.
+pub(crate) fn unique_name_from(base: &str, next: &mut std::collections::HashMap<String, usize>, taken: impl Fn(&str) -> bool) -> String {
+    if !taken(base) {
+        return base.to_string();
+    }
+    let i = next.entry(base.to_lowercase()).or_insert(2);
+    loop {
+        let n = format!("{base} {i}");
+        *i += 1;
+        if !taken(&n) {
+            return n;
+        }
+    }
+}
+
+/// The most presets one presets file imports: each is looked up among the saved ones.
+pub(crate) const MAX_IMPORTED_PRESETS: usize = 1000;
+
 pub(crate) use edit::{settle_interaction, typing_in_progress};
 pub(crate) use object::bounds_rewrite;
 pub(crate) use vectorcraft_doc::range::parse_range;

crates/engine/src/cmd/pdfcmds.rs

@@ -8,7 +8,7 @@ use serde_json::{Value, json};
 use vectorcraft_pdf::{PdfPreset, builtin_preset, builtin_presets};
 
 use super::fileio::pdf::{find_preset, resolve};
-use super::{CommandSpec, Result, Session, always, bad, bool_or, cmd, str_param, unique_name};
+use super::{CommandSpec, Result, Session, always, bad, bool_or, cmd, str_param};
 
 /// The `format` of a PDF presets file, also its extension.
 pub const PRESET_FORMAT: &str = "vcpdfpresets";
@@ -196,8 +196,12 @@ fn import(s: &mut Session, p: &Value) -> Result<Value> {
     for q in &file.presets {
         q.settings.check_values().map_err(|e| bad(C, format!("`{}`: {e}", q.name)))?;
     }
+    if file.presets.len() > super::MAX_IMPORTED_PRESETS {
+        return Err(bad(C, format!("a PDF presets file with over {} presets", super::MAX_IMPORTED_PRESETS)));
+    }
     let replace = bool_or(p, "replace", false);
     let mut imported = vec![];
+    let mut next = std::collections::HashMap::new();
     for mut preset in file.presets {
         preset.settings.clear_passwords();
         let base = Some(preset.name.trim()).filter(|n| !n.is_empty()).unwrap_or("PDF Preset").to_string();
@@ -211,7 +215,7 @@ fn import(s: &mut Session, p: &Value) -> Result<Value> {
                 }
             }
             None => {
-                preset.name = unique_name(&base, |n| s.pdf_preset_taken(n, None));
+                preset.name = super::unique_name_from(&base, &mut next, |n| s.pdf_preset_taken(n, None));
                 imported.push(preset.name.clone());
                 s.store_pdf_preset(None, &preset);
                 s.prefs.pdf_presets.push(preset);

crates/engine/src/cmd/printpresets.rs

@@ -8,7 +8,7 @@ use vectorcraft_pdf::PrintSettings;
 
 use super::fileio::pdf::changed;
 use super::print::settings_over;
-use super::{CommandSpec, EngineError, Result, Session, always, bad, bool_or, cmd, str_param, unique_name};
+use super::{CommandSpec, EngineError, Result, Session, always, bad, bool_or, cmd, str_param};
 
 /// The built-in preset's name.
 pub const DEFAULT_PRESET: &str = "[Default]";
@@ -221,8 +221,12 @@ fn import(s: &mut Session, p: &Value) -> Result<Value> {
     for q in &file.presets {
         q.settings.check().map_err(|e| bad(C, format!("`{}`: {e}", q.name)))?;
     }
+    if file.presets.len() > super::MAX_IMPORTED_PRESETS {
+        return Err(bad(C, format!("a print presets file with over {} presets", super::MAX_IMPORTED_PRESETS)));
+    }
     let replace = bool_or(p, "replace", false);
     let mut imported = vec![];
+    let mut next = std::collections::HashMap::new();
     for mut preset in file.presets {
         // [Default] comes in as a saved copy ("Default 2"…): the built-in one stays.
         let name = preset.name.trim().trim_start_matches('[').trim_end_matches(']').trim();
@@ -236,7 +240,7 @@ fn import(s: &mut Session, p: &Value) -> Result<Value> {
                 }
             }
             None => {
-                preset.name = unique_name(&base, |n| s.print_preset_taken(n, None));
+                preset.name = super::unique_name_from(&base, &mut next, |n| s.print_preset_taken(n, None));
                 imported.push(preset.name.clone());
                 s.prefs.print_presets.push(preset);
             }

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();