Symbols: Reset Transformation keeps the art's size when the stored size is not positive

crates/engine/src/cmd/brushsym/symbols.rs

@@ -710,8 +710,8 @@ pub fn reset_transformation(boxes: &vectorcraft_doc::SymbolBoxes, n: &Node) -> O
     if n.extras().perspective.is_some() || !d.symbols.iter().any(|s| s.name == *symbol) {
         return None;
     }
-    let (w, h) = natural_size(d, symbol);
-    let scale = Affine::scale_non_uniform(w / (2.0 * HALF), h / (2.0 * HALF));
+    // The symbol's stored natural size, or the art unscaled when that size is not positive and finite.
+    let scale = d.symbol_natural_xf(symbol);
     // The art's box in symbol space (the ±HALF square when the art cannot be measured): its
     // center keeps its place on the page.
     let art = boxes.art_bounds(symbol).unwrap_or_else(|| vectorcraft_geom::Rect::new(-HALF, -HALF, HALF, HALF));

crates/engine/src/tests/brushsym.rs

@@ -1422,6 +1422,27 @@ fn reset_transformation_keeps_the_center_of_art_away_from_the_origin() {
     assert!((after.width() - 20.0).abs() < 1e-9 && (after.height() - 20.0).abs() < 1e-9, "{after:?}");
 }
 
+/// A stored natural size that is not positive (from a damaged file) does not flatten the instance:
+/// Reset Transformation gives it the art's own size, as drawing the symbol does.
+#[test]
+fn reset_transformation_ignores_a_stored_size_that_is_not_positive() {
+    let mut s = session();
+    let r = rect(&mut s, 0.0, 0.0, 20.0, 20.0);
+    let art = node(&s, r);
+    s.execute("edit.clear", &json!({"ids": [r.0]})).unwrap();
+    let st = s.doc_mut().unwrap();
+    let d = std::sync::Arc::make_mut(&mut st.doc);
+    d.symbols.push(vectorcraft_doc::Symbol { dynamic: false, name: "Flat".into(), art: std::sync::Arc::new(art) });
+    d.unknown.insert(vectorcraft_doc::SYMBOL_SIZES.to_string(), json!({"Flat": [0.0, 20.0]}));
+    let layer = d.layers[0].id;
+    let id = d.alloc_id();
+    let xf = vectorcraft_geom::Affine::translate((100.0, 100.0)) * vectorcraft_geom::Affine::rotate(0.5);
+    d.insert(Some(layer), usize::MAX, Node::new(id, NodeKind::SymbolInstance { symbol: "Flat".into(), xf })).unwrap();
+    assert_eq!(s.execute("symbol.instance.resetTransform", &json!({"ids": [id.0]})).unwrap()["ids"], json!([id.0]));
+    let after = s.doc().unwrap().doc.bounds_of(&[id], false).unwrap();
+    assert!((after.width() - 20.0).abs() < 1e-9 && (after.height() - 20.0).abs() < 1e-9, "{after:?}");
+}
+
 /// Reset Transformation adds no undo step for an instance already at its symbol's scale or for
 /// one in perspective, and refuses an id naming no object and objects without an instance,
 /// changing nothing.

docs/target-app-parity.md

@@ -713,6 +713,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   - **Delete Symbol asks first** ([Symbols panel](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/symbols-panel-options.html), [symbol libraries](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/create-or-import-symbol-libraries.html), [Alt-click Delete](https://helpx.adobe.com/illustrator/using/default-keyboard-shortcuts.html)): the Symbols panel's Delete Symbol button and menu item ask "Delete the selected symbol?" with Yes and No for a symbol no instance uses. For a symbol with placed instances they ask with Expand Instances (the instances become ordinary art), Delete Instances and Cancel; either Instances button deletes the symbol in one undo step. Alt-click on the button deletes an unused symbol without asking and still asks about one with instances. A question left open while another document became active deletes nothing. `symbol.delete` itself does not ask. Tests: `panels::symbols::tests::delete_symbol_asks_first_and_alt_click_deletes_an_unused_symbol_at_once`, `the_in_use_question_expands_or_deletes_the_instances`, `a_stale_delete_symbol_question_deletes_nothing`, `the_delete_symbol_questions_show_their_buttons`.
   - **Symbols › Select All Unused** ([Symbols panel](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/symbols-panel-options.html), #4918): the Symbols panel menu's Select All Unused shows the symbols nothing places selected (`symbol.unused`): instances in the art (opacity masks included), graph designs, pattern tiles and brush art count, and so do instances in a used symbol's art. Delete Symbol, the button or the menu item, then asks "Delete the selected symbols?" once and deletes those still unused in one undo step (`symbol.delete {names}`); Alt-click on the button deletes them without asking, and a click on a symbol picks just it again. Tests: `tests::brushsym::symbol_unused_lists_the_symbols_nothing_places_and_delete_takes_several`, `panels::symbols::tests::select_all_unused_picks_the_unused_symbols_and_delete_deletes_them`, `dialogs::symbol_delete::tests::several_symbols_get_the_plural_question`.
   - **Expand of symbol instances:** Object › Expand turns selected symbol instances (without effects, not in perspective, in groups or placed documents too) into their art as Break Link to Symbol places it, one level deep, as one undo step; the Expand dialog's Fill and Stroke reach that art (`object.expand`, `crates/engine/src/tests/expand_symbols.rs`; estimated, score unchanged).
+  - **Reset Transformation** ([Transform symbols](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/transform-symbols.html), [Symbols panel options](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/symbols-panel-options.html)): the Symbols panel menu's Reset Transformation and the Control bar's Reset, shown while symbol instances are selected, give the selected instances their symbol's own scale again, without rotation or shear, as one undo step (`symbol.instance.resetTransform`); an instance in perspective is left as it is. VectorCraft's own rules: each instance keeps the center of its bounding box in place, reflection is removed too, and the menu item and the button are enabled only while a selected instance would change. Tests: `tests::brushsym::reset_transformation_restores_the_symbols_scale_and_keeps_the_center`, `reset_transformation_keeps_the_center_of_art_away_from_the_origin`, `reset_transformation_ignores_a_stored_size_that_is_not_positive`, `reset_transformation_leaves_unchanged_instances_and_refuses_bad_ids`, `panels::symbols::tests::reset_transformation_is_enabled_for_a_transformed_instance_and_resets_it`.
   - **Reset Transformation** ([Transform symbols](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/transform-symbols.html), [Symbols panel options](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/symbols-panel-options.html)): the Symbols panel menu's Reset Transformation and the Control bar's Reset, shown while symbol instances are selected, give the selected instances their symbol's own scale again, without rotation or shear, as one undo step (`symbol.instance.resetTransform`); an instance in perspective is left as it is. VectorCraft's own rules: each instance keeps the center of its bounding box in place, reflection is removed too, and the menu item and the button are enabled only while a selected instance would change. Tests: `tests::brushsym::reset_transformation_restores_the_symbols_scale_and_keeps_the_center`, `reset_transformation_keeps_the_center_of_art_away_from_the_origin`, `reset_transformation_leaves_unchanged_instances_and_refuses_bad_ids`, `panels::symbols::tests::reset_transformation_is_enabled_for_a_transformed_instance_and_resets_it`.
   - **Reset Transformation** ([Transform symbols](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/transform-symbols.html), [Symbols panel options](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/symbols-panel-options.html)): the Symbols panel menu's Reset Transformation and the Control bar's Reset, shown while symbol instances are selected, give the selected instances their symbol's own scale again, without rotation or shear, as one undo step (`symbol.instance.resetTransform`); an instance in perspective is left as it is. VectorCraft's own rules: each instance keeps the center of its bounding box in place, reflection is removed too, and the menu item and the button are enabled only while a selected instance would change. Tests: `tests::brushsym::reset_transformation_restores_the_symbols_scale_and_keeps_the_center`, `reset_transformation_leaves_unchanged_instances_and_refuses_bad_ids`, `panels::symbols::tests::reset_transformation_is_enabled_for_a_transformed_instance_and_resets_it`.
   - **Expand of dimensions:** Object › Expand, Expand Appearance, Create Outlines and Outline Stroke turn a dimension whose art they change into a plain group of that art, which stays as it is through later moves, scales and edits of what it measured; undo gives the live dimension back (`crates/engine/tests/it/dimensions.rs`; VectorCraft's own rule; estimated, score unchanged).