fix(paint): preserve new-art defaults when paint edits are rejected

crates/engine/src/cmd/paint.rs

@@ -375,15 +375,7 @@ fn apply_to_proxy(s: &mut Session, p: &Value, paint: Paint) -> Result<Value> {
 /// remember the paint.
 fn apply_paint(s: &mut Session, p: &Value, paint: Paint, fill: bool) -> Result<Value> {
     let cmd = if fill { "paint.setFill" } else { "paint.setStroke" };
-    // New art gets the paint fitted to itself, not placed where this one is.
-    if fill {
-        s.paint.fill = unplaced(&paint);
-    } else {
-        s.paint.stroke = unplaced(&paint);
-    }
-    if bool_or(p, "focus", true) {
-        s.fill_active = fill;
-    }
+    // Resolve the requested targets before mutating defaults or the active proxy.
     let item = item_target(s, p, cmd)?.of_kind(s, fill);
     let selected = item.targets(s, p)?;
     let ids = super::graph::paint_targets(&s.doc()?.doc, &selected);
@@ -423,6 +415,16 @@ fn apply_paint(s: &mut Session, p: &Value, paint: Paint, fill: bool) -> Result<V
             Ok(())
         },
     )?;
+    // Rejected edits leave the next shape's appearance and active proxy untouched.
+    // New art takes an unplaced gradient so that it fits the new object's own bounds.
+    if fill {
+        s.paint.fill = unplaced(&paint);
+    } else {
+        s.paint.stroke = unplaced(&paint);
+    }
+    if bool_or(p, "focus", true) {
+        s.fill_active = fill;
+    }
     s.remember_paint(&paint);
     ok()
 }
@@ -436,7 +438,6 @@ fn set_run_stroke(style: &mut CharStyle, paint: Paint) {
 }
 
 fn swap(s: &mut Session, p: &Value) -> Result<Value> {
-    std::mem::swap(&mut s.paint.fill, &mut s.paint.stroke);
     let ids = paint_targets(s, p)?;
     if !ids.is_empty() {
         s.edit("Swap Fill and Stroke", |d, _| {
@@ -458,11 +459,11 @@ fn swap(s: &mut Session, p: &Value) -> Result<Value> {
             Ok(())
         })?;
     }
+    std::mem::swap(&mut s.paint.fill, &mut s.paint.stroke);
     ok()
 }
 
 fn default_paint(s: &mut Session, p: &Value) -> Result<Value> {
-    super::newart::reset(s);
     let ids = paint_targets(s, p)?;
     if !ids.is_empty() {
         s.edit("Default Fill and Stroke", |d, _| {
@@ -481,6 +482,7 @@ fn default_paint(s: &mut Session, p: &Value) -> Result<Value> {
             Ok(())
         })?;
     }
+    super::newart::reset(s);
     ok()
 }
 

crates/engine/src/tests.rs

@@ -134,6 +134,40 @@ fn fill_and_stroke_commands() {
     s.execute("paint.setFill", &json!({"gradient": {"kind": "radial"}})).unwrap();
 }
 
+
+#[test]
+fn rejected_paint_edits_leave_new_art_defaults_and_focus_unchanged() {
+    let mut s = session();
+    let id = rect(&mut s, 0.0, 0.0, 10.0, 10.0);
+    s.execute("paint.setFill", &json!({"color": "#00ff00"})).unwrap();
+    s.execute("paint.setStroke", &json!({"color": "#ff0000"})).unwrap();
+    let defaults = s.paint.clone();
+    let focused = s.fill_active;
+    let original_fill = s.doc().unwrap().doc.node(id).unwrap().appearance.fill_paint();
+    let original_stroke = s.doc().unwrap().doc.node(id).unwrap().appearance.stroke_paint();
+
+    // Both shortcut commands used to change defaults before checking invalid ids.
+    for (command, params) in [
+        ("paint.swap", json!({"ids": "not an array"})),
+        ("paint.default", json!({"ids": ["not an object id"]})),
+        ("paint.setFill", json!({"color": "#123456", "ids": [false]})),
+        ("paint.setStroke", json!({"color": "#123456", "ids": "not an array"})),
+        ("paint.setFill", json!({"color": "#123456", "item": "invalid"})),
+    ] {
+        assert!(s.execute(command, &params).is_err(), "{command} should reject {params}");
+        assert_eq!(s.paint, defaults, "{command} changed new-art defaults on failure");
+        assert_eq!(s.fill_active, focused, "{command} changed the active proxy on failure");
+        let appearance = &s.doc().unwrap().doc.node(id).unwrap().appearance;
+        assert_eq!(appearance.fill_paint(), original_fill);
+        assert_eq!(appearance.stroke_paint(), original_stroke);
+    }
+
+    // Successful operations still update both the selected object and new-art defaults.
+    s.execute("paint.swap", &json!({})).unwrap();
+    assert_eq!(s.paint.fill, defaults.stroke);
+    assert_eq!(s.paint.stroke, defaults.fill);
+}
+
 #[test]
 fn select_same_fill() {
     let mut s = session();