fix: renaming a body keeps the names of its duplicates (#1056)

Bodies imported with the same label come in as X, X (2), X (3). Renaming one of them no longer renumbers the others: body.rename now pins the current names of the feature's other bodies when it stores the new one, so later renames, materials, appearances and features still find them.

crates/engine/src/tests.rs

@@ -2880,6 +2880,67 @@ fn renaming_a_pattern_copy_keeps_the_other_copies_names() {
     assert_eq!(names, ["X", "Second", "Third"]);
 }
 
+/// Three solids in one STEP file that carry the same label: the file written for three boxes, each
+/// named `X`.
+fn step_three_solids_labelled_x(tag: &str) -> std::path::PathBuf {
+    let dir = std::env::temp_dir().join(format!("solidcraft-step-{tag}-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let mut s = Session::default();
+    for (i, label) in ["Aa", "Bb", "Cc"].iter().enumerate() {
+        let corner = [30.0 * i as f64, 0.0, 0.0];
+        run(&mut s, "solid.box", json!({"length": 10, "width": 10, "height": 10, "corner": corner, "operation": "new_body", "body_name": label}));
+    }
+    let p = dir.join("Three.step");
+    run(&mut s, "file.export", json!({"path": p.to_string_lossy()}));
+    let mut text = std::fs::read_to_string(&p).unwrap();
+    for label in ["Aa", "Bb", "Cc"] {
+        assert!(text.contains(&format!("MANIFOLD_SOLID_BREP('{label}'")), "the file names its solids: {label}");
+        text = text.replace(&format!("MANIFOLD_SOLID_BREP('{label}'"), "MANIFOLD_SOLID_BREP('X'");
+    }
+    std::fs::write(&p, text).unwrap();
+    p
+}
+
+/// Renaming one of several imported bodies that share a label leaves the names of the others alone:
+/// the model lists them as `X`, `X (2)`, `X (3)`, and `X (3)` is still there after `X (2)` is renamed.
+#[test]
+fn renaming_an_imported_body_keeps_the_names_of_its_duplicates() {
+    let p = step_three_solids_labelled_x("duplicate-labels");
+    let mut s = Session::default();
+    run(&mut s, "file.insert_step", json!({"path": p.to_string_lossy()}));
+    let names = |s: &Session| s.model.state().bodies.iter().map(|b| b.name.clone()).collect::<Vec<_>>();
+    assert_eq!(names(&s), ["X", "X (2)", "X (3)"]);
+    let x_of =
+        |s: &mut Session, body: &str| run(s, "inspect.measure", json!({"bodies": [body]}))["bodies"][0]["bbox"]["min"][0].as_f64().map(f64::round);
+    assert_eq!(x_of(&mut s, "X (3)"), Some(60.0));
+    run(&mut s, "body.rename", json!({"body": "X (2)", "name": "Second"}));
+    assert_eq!(names(&s), ["X", "Second", "X (3)"]);
+    assert_eq!(x_of(&mut s, "X (3)"), Some(60.0), "X (3) is still the solid at x = 60");
+    run(&mut s, "body.rename", json!({"body": "X (3)", "name": "Third"}));
+    assert_eq!(names(&s), ["X", "Second", "Third"]);
+    assert_eq!(x_of(&mut s, "Third"), Some(60.0));
+    // The names survive a rebuild and a reopen of the saved design.
+    let design = p.with_file_name("Three.solidcraft");
+    run(&mut s, "file.save_as", json!({"path": design.to_string_lossy()}));
+    let mut r = Session::default();
+    run(&mut r, "doc.open", json!({"path": design.to_string_lossy()}));
+    assert_eq!(names(&r), ["X", "Second", "Third"]);
+}
+
+/// The same when the first of the three is renamed: `X (2)` and `X (3)` do not slide down to `X` and
+/// `X (2)`, and what is set on one of them (a material) stays with it.
+#[test]
+fn renaming_the_first_imported_duplicate_keeps_the_numbers_of_the_others() {
+    let p = step_three_solids_labelled_x("duplicate-labels-first");
+    let mut s = Session::default();
+    run(&mut s, "file.insert_step", json!({"path": p.to_string_lossy()}));
+    run(&mut s, "material.assign", json!({"bodies": ["X (3)"], "material": "Steel"}));
+    run(&mut s, "body.rename", json!({"body": "X", "name": "First"}));
+    let names: Vec<String> = s.model.state().bodies.iter().map(|b| b.name.clone()).collect();
+    assert_eq!(names, ["First", "X (2)", "X (3)"]);
+    assert!(s.doc.materials.contains_key("X (3)"), "the material is still on X (3): {:?}", s.doc.materials.keys().collect::<Vec<_>>());
+}
+
 /// Parameters that work are listed in the command's params doc, which is all agents see (#271).
 #[test]
 fn params_docs_list_working_parameters() {