#1007: Reverse Gradient mirrors off-centre midpoints

Reversal read the midpoints after Gradient::reverse had reordered the stops, so each stop
took the wrong segment's midpoint: red-to-blue with its midpoint at 20% reversed to a 50%
midpoint instead of 80%, moving the transition.

Gradient::reverse now mirrors each segment's midpoint with it, so a reversed gradient is the
same ramp the other way round; paint.editGradient's own (wrong) pass is gone, and the SVG
importer's reflect spread, which had a correct copy of the same mirroring, uses it too.

Tests: two- and three-stop gradients with off-centre midpoints sample the same reversed (t vs
1 - t) and come back after two reversals; paint.editGradient reverse turns a 0.2 midpoint into
0.8.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

# Conflicts:
#	ROADMAP.md

ROADMAP.md

@@ -123,7 +123,7 @@ Ranked; detail in [docs/roadmap.md](docs/roadmap.md) and [docs/gaps.md](docs/gap
 
 | Date | What landed |
 |---|---|
-| 2026-10-11 | Effect › Brush Strokes: Accented Edges, Angled Strokes, Crosshatch, Dark Strokes, Ink Outlines, Spatter, Sprayed Strokes, Sumi-e (G2) |
+| 2026-10-11 | Effect › Brush Strokes: Accented Edges, Angled Strokes, Crosshatch, Dark Strokes, Ink Outlines, Spatter, Sprayed Strokes, Sumi-e (G2). Command parameters from agents and files checked before anything changes (paint, place, cuts, dashes, crop, asset ids, anchors, paths, distort; #984–#999); command dialogs keep whole numbers whole, so Create Object Mosaic takes the tiles typed (#1000); stepper arrows take Shift (×10) and Ctrl/Cmd (÷10) like the arrow keys (#991). Exports and Rasterize supersample Art Optimized edges, so shapes meeting edge to edge leave no seam (#983). Character and paragraph styles take leading, kerning, mojikumi and the other attributes left out at their defaults (#1001). Drawing, typing and pasting with no layer shown and unlocked is refused instead of adding art to a hidden or locked layer (#1002). MCP `add_text` gives type on or in a path the colour asked for (#1003). MCP `screenshot` of a connected app renders the artboard asked for (#1004). `vectorcraft-cli run` ends quietly when its reader closes early (#1005). Select › All on Active Artboard selects on the artboard made active, not always the first (#1006). Reverse Gradient keeps off-centre midpoints, mirrored (#1007). |
 | 2026-10-10 | Initial live Revolve (Effect › 3D and Materials, #846, #605), in its own `three-d` crate. Progress docs re-measured and restructured to the craftrules standard (this page, `docs/target-app-parity.md`, `gaps.md`, `ui-parity.md`, the format, hardware, localization, effects and type checklists). Same day: v0.8.0; Effect › Distort, Pixelate and Texture filters (13); German interface; Variables (data merge); Graph Type value axes and tick marks; restart when the first frame never reaches the screen (#964) |
 | 2026-10-09 | Radial Blur, Smart Blur, Unsharp Mask (gap 2 begins); 340 commits, the busiest day |
 | 2026-10-08 | v0.5.0–v0.7.0; community contributions: Pen and shape-tool modifiers, Layers, Artboards, Japanese composition, Hebrew/Arabic type, interface languages, saved selections |

apps/vectorcraft-cli/src/main.rs

@@ -292,7 +292,21 @@ fn run(args: &[String]) -> Result<(), String> {
 
     let mut h = Headless::new();
     let mut out = std::io::stdout().lock();
-    let mut emit = |v: Value| writeln!(out, "{v}").map_err(|e| e.to_string());
+    // A reader that stopped early (a closed pipe) isn't an error, and the batch goes on: its later
+    // steps (an export…) still run, unprinted.
+    let mut closed = false;
+    let mut emit = |v: Value| {
+        if closed {
+            return Ok(());
+        }
+        match writeln!(out, "{v}") {
+            Err(e) if e.kind() == std::io::ErrorKind::BrokenPipe => {
+                closed = true;
+                Ok(())
+            }
+            r => r.map_err(|e| e.to_string()),
+        }
+    };
     if let Some(path) = &input {
         let r = h.call("app.open", json!({"path": path})).map_err(|e| format!("open {path}: {e}"))?;
         emit(json!({"step": "open", "path": path, "result": r}))?;

apps/vectorcraft-cli/tests/cli.rs

@@ -297,3 +297,21 @@ fn closed_stdout_ends_quietly() {
     let err = String::from_utf8_lossy(&out.stderr);
     assert!(out.status.success() && !err.contains("panicked"), "{:?}: {err}", out.status);
 }
+
+/// #1005: `run` whose reader has gone (`vectorcraft-cli run … | true`) ends quietly with status 0,
+/// and its later steps still run; a failing step still fails.
+#[test]
+fn run_with_a_closed_stdout_ends_quietly_and_finishes_the_batch() {
+    let svg = tmp("closed-run.svg");
+    let _ = std::fs::remove_file(&svg);
+    let rect = r#"{"x":1,"y":1,"width":5,"height":5}"#;
+    let args = ["run", "--cmd", "document.json", "--cmd", "shape.rectangle", "--params", rect, "--export", svg.to_str().unwrap()];
+    let mut child = Command::new(BIN).args(args).stdout(Stdio::piped()).stderr(Stdio::piped()).spawn().unwrap();
+    drop(child.stdout.take());
+    let out = child.wait_with_output().unwrap();
+    let err = String::from_utf8_lossy(&out.stderr);
+    assert!(out.status.success() && err.is_empty(), "{:?}: {err}", out.status);
+    assert!(svg.is_file(), "the export after the closed reader still ran");
+    let out = Command::new(BIN).args(["run", "--cmd", "not-a-command"]).stdout(Stdio::null()).output().unwrap();
+    assert!(!out.status.success());
+}

crates/color/src/gradient.rs

@@ -131,10 +131,18 @@ impl Gradient {
             std::iter::once((s.offset, s.color, s.opacity, None)).chain(mid)
         })
     }
+    /// The same ramp the other way round: the stops in reverse order at mirrored offsets, each
+    /// segment's midpoint mirrored with it.
     pub fn reverse(&mut self) {
         self.stops.reverse();
-        for s in &mut self.stops {
-            s.offset = 1.0 - s.offset;
+        for i in 0..self.stops.len() {
+            // A midpoint belongs to the segment after its stop: reversed, stop i's segment is the
+            // one the next stop (not yet mirrored) had, measured from the other end.
+            let mid = self.stops.get(i + 1).map_or(0.5, |n| 1.0 - n.midpoint);
+            if let Some(s) = self.stops.get_mut(i) {
+                s.offset = 1.0 - s.offset;
+                s.midpoint = mid;
+            }
         }
     }
     pub fn sort(&mut self) {
@@ -569,6 +577,32 @@ mod tests {
         assert_eq!(g.stops[0].offset, 0.0);
     }
 
+    /// #1007: reversing mirrors off-centre midpoints with their segments, so the ramp is the same
+    /// the other way round.
+    #[test]
+    fn reverse_mirrors_midpoints() {
+        let stop = |offset, hex, midpoint| GradientStop { midpoint, ..GradientStop::new(offset, Color::from_hex(hex).unwrap()) };
+        let two = Gradient { kind: GradientKind::Linear, stops: vec![stop(0.0, "#ff0000", 0.2), stop(1.0, "#0000ff", 0.5)] };
+        let three =
+            Gradient { kind: GradientKind::Linear, stops: vec![stop(0.0, "#ff0000", 0.2), stop(0.3, "#00ff00", 0.8), stop(1.0, "#0000ff", 0.5)] };
+        for g in [two, three] {
+            let mut r = g.clone();
+            r.reverse();
+            let mids: Vec<f32> = r.stops.iter().map(|s| s.midpoint).collect();
+            let want: Vec<f32> = g.stops.iter().rev().skip(1).map(|s| 1.0 - s.midpoint).chain([0.5]).collect();
+            assert!(mids.iter().zip(&want).all(|(a, b)| (a - b).abs() < 1e-6), "{mids:?} {want:?}");
+            for i in 0..=20 {
+                let t = i as f32 / 20.0;
+                let ((a, ao), (b, bo)) = (g.sample(t), r.sample(1.0 - t));
+                let same = a.to_rgba8(1.0).iter().zip(b.to_rgba8(1.0)).all(|(x, y)| x.abs_diff(y) <= 1);
+                assert!(same && (ao - bo).abs() < 1e-6, "t {t}: {a:?} vs {b:?}");
+            }
+            r.reverse();
+            let back = r.stops.iter().zip(&g.stops).all(|(a, b)| (a.offset - b.offset).abs() < 1e-6 && (a.midpoint - b.midpoint).abs() < 1e-6);
+            assert!(back, "reversed twice, it is as it was: {:?}", r.stops);
+        }
+    }
+
     fn close(a: Point, b: Point) -> bool {
         a.distance(b) < 1e-9
     }

crates/engine/src/cmd/assets.rs

@@ -80,12 +80,13 @@ fn clean_name(name: &str) -> Option<String> {
 
 fn add(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "assets.add";
-    let ids = match ids_param(p, "ids") {
-        Some(ids) => {
-            let d = &s.doc()?.doc;
-            roots_of(d, d.paint_order(ids))
-        }
-        None => selected_roots(s)?,
+    let ids = if p.get("ids").is_some_and(|v| !v.is_null()) {
+        // An explicit list is authoritative: never silently drop malformed or stale ids.
+        let ids = checked_ids_param(s, p, "ids", C)?;
+        let d = &s.doc()?.doc;
+        roots_of(d, d.paint_order(ids))
+    } else {
+        selected_roots(s)?
     };
     if ids.is_empty() {
         return Err(bad(C, "select the art to collect (or give its ids)"));

crates/engine/src/cmd/brushsym.rs

@@ -603,7 +603,7 @@ fn symbol_place(s: &mut Session, p: &Value) -> Result<Value> {
     let centre = d.artboards.first().map(|a| a.rect.center()).unwrap_or(Point::ZERO);
     let c = Point::new(f64_or(p, "x", centre.x), f64_or(p, "y", centre.y));
     let size = natural_size(d, &name);
-    let parent = s.doc()?.insertion_parent();
+    let parent = s.doc()?.target_parent()?;
     let id = s.edit("Place Symbol Instance", |d, sel| {
         let id = d.alloc_id();
         d.insert(parent, usize::MAX, Node::new(id, NodeKind::SymbolInstance { symbol: name.clone(), xf: place_xf(c, size) }))?;
@@ -843,7 +843,8 @@ fn symbol_spray(s: &mut Session, p: &Value) -> Result<Value> {
     let alt = bool_or(p, "alt", false);
     let size = natural_size(&st.doc, &name);
     let set = st.selection.objects.first().copied().filter(|id| st.selection.len() == 1 && st.doc.node(*id).is_some_and(is_symbol_set));
-    let parent = st.insertion_parent();
+    // Only a new Symbol Set needs a layer that takes new art.
+    let parent = if alt || set.is_some() { st.insertion_parent() } else { st.target_parent()? };
     if alt {
         // Remove instances of this symbol under the brush (within the set, or anywhere).
         let d = &st.doc;

crates/engine/src/cmd/create.rs

@@ -79,7 +79,7 @@ pub(crate) fn add_node(s: &mut Session, label: &str, kind: NodeKind, appearance:
 
 /// Insert a new object looking like `look` (drawing modes apply); select it.
 pub(crate) fn add_look(s: &mut Session, label: &str, kind: NodeKind, look: NewArt, name: Option<String>) -> Result<Value> {
-    let parent = s.doc()?.insertion_parent();
+    let parent = s.doc()?.target_parent()?;
     let mode = s.draw_mode;
     let inside = s.draw_inside;
     let behind_of = s.doc()?.selection.in_paint_order(&s.doc()?.doc).first().copied();
@@ -298,7 +298,7 @@ fn flare(s: &mut Session, p: &Value) -> Result<Value> {
         };
         parts.push(("Ring", circle(at, rr), radial(at, rr, stops), 1.0));
     }
-    let parent = s.doc()?.insertion_parent();
+    let parent = s.doc()?.target_parent()?;
     let id = s.edit("Flare", |d, sel| {
         let children = parts
             .into_iter()
@@ -352,7 +352,7 @@ fn arc(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 fn grid_group(s: &mut Session, label: &str, paths: Vec<PathData>) -> Result<Value> {
-    let parent = s.doc()?.insertion_parent();
+    let parent = s.doc()?.target_parent()?;
     let look = s.new_art_look(vectorcraft_color::Paint::None, s.paint.stroke.clone(), s.paint.stroke_width);
     let id = s.edit(label, |d, sel| {
         let children = paths
@@ -385,15 +385,24 @@ fn polar_grid(s: &mut Session, p: &Value) -> Result<Value> {
     grid_group(s, "Polar Grid", shapes::polar_grid(r, c, rad))
 }
 
-pub(crate) fn anchor_from_json(v: &Value) -> Option<Anchor> {
-    let p = Point::new(v.get("x")?.as_f64()?, v.get("y")?.as_f64()?);
-    let h_in = point_param(v, "in").unwrap_or(p);
-    let h_out = point_param(v, "out").unwrap_or(p);
-    let mut a = Anchor::with_handles(p, h_in, h_out);
-    if v.get("smooth").and_then(Value::as_bool) == Some(true) {
-        a.kind = AnchorKind::Smooth;
+/// An anchor `{x, y, in?, out?, smooth?}` given to `cmd` (handles `[x, y]`, at the anchor when
+/// absent or null): anything malformed fails rather than being left out or replaced by a default,
+/// which would change the path's shape.
+pub(crate) fn anchor_from_json(v: &Value, cmd: &str) -> Result<Anchor> {
+    let coord =
+        |key: &str| v.get(key).and_then(Value::as_f64).filter(|n| n.is_finite()).ok_or_else(|| bad(cmd, format!("anchor `{key}` must be a number")));
+    let p = Point::new(coord("x")?, coord("y")?);
+    let handle = |key: &str| match v.get(key).filter(|h| !h.is_null()) {
+        None => Ok(p),
+        Some(h) => finite_numbers(h).map(|[x, y]| Point::new(x, y)).ok_or_else(|| bad(cmd, format!("anchor `{key}` must be [x, y]"))),
+    };
+    let mut anchor = Anchor::with_handles(p, handle("in")?, handle("out")?);
+    match v.get("smooth").filter(|b| !b.is_null()) {
+        None | Some(Value::Bool(false)) => {}
+        Some(Value::Bool(true)) => anchor.kind = AnchorKind::Smooth,
+        Some(_) => return Err(bad(cmd, "anchor `smooth` must be true or false")),
     }
-    Some(a)
+    Ok(anchor)
 }
 
 fn path_create(s: &mut Session, p: &Value) -> Result<Value> {
@@ -406,8 +415,8 @@ fn path_create(s: &mut Session, p: &Value) -> Result<Value> {
             .and_then(Value::as_array)
             .ok_or_else(|| bad("path.create", "missing anchors"))?
             .iter()
-            .filter_map(anchor_from_json)
-            .collect();
+            .map(|a| anchor_from_json(a, "path.create"))
+            .collect::<Result<_>>()?;
         if anchors.is_empty() {
             return Err(bad("path.create", "need at least one anchor"));
         }

crates/engine/src/cmd/cut.rs

@@ -221,8 +221,8 @@ fn rect_cut(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "path.rectCut";
     let rect = match p.get("rect") {
         Some(v) => {
-            let a: Vec<f64> = v.as_array().map(|a| a.iter().filter_map(Value::as_f64).collect()).unwrap_or_default();
-            let [x, y, w, h] = a[..] else { return Err(bad(C, "rect must be [x, y, width, height]")) };
+            // All four or nothing: a malformed entry dropped would cut a different region.
+            let [x, y, w, h] = finite_numbers(v).ok_or_else(|| bad(C, "rect must be [x, y, width, height]"))?;
             Rect::new(x, y, x + w, y + h).abs()
         }
         None => Rect::from_points(point_req(p, "from", C)?, point_req(p, "to", C)?),

crates/engine/src/cmd/edit.rs

@@ -346,7 +346,7 @@ fn paste_clip(s: &mut Session, p: &Value, mode: PasteMode, clip: &Clipboard, cho
     let off = s.prefs.paste_offset;
     let st = s.doc()?;
     let same_doc = clip.source_doc == Some(st.uid);
-    let parent = st.insertion_parent();
+    let parent = st.target_parent()?;
     // A copied artboard comes back with its art: right of the last artboard, or where it was
     // (Paste in Place, in Front, in Back). Paste on All Artboards pastes only the art.
     let board = clip

crates/engine/src/cmd/gradient.rs

@@ -270,13 +270,8 @@ pub(crate) fn apply_gradient_edit_in(
         gp.swatch = None;
     }
     if bool_or(p, "reverse", false) {
+        // Midpoints mirrored with their segments.
         gp.gradient.reverse();
-        // Midpoints belong to the segment to the right; mirror them.
-        let n = gp.gradient.stops.len();
-        let mids: Vec<f32> = gp.gradient.stops.iter().map(|s| s.midpoint).collect();
-        for i in 0..n {
-            gp.gradient.stops[i].midpoint = if i + 1 < n { 1.0 - mids[n - 2 - i] } else { 0.5 };
-        }
     }
     // Angle and aspect edits keep the focal point in its place in the extent ellipse.
     let before = gp.geom;

crates/engine/src/cmd/graph.rs

@@ -831,7 +831,7 @@ fn create(s: &mut Session, p: &Value) -> Result<Value> {
         spec.categories = vec!["A".into(), "B".into(), "C".into(), "D".into()];
         spec.rows = vec![vec![3.0, 2.0], vec![5.0, 4.0], vec![4.0, 6.0], vec![7.0, 5.0]];
     }
-    let parent = s.doc()?.insertion_parent();
+    let parent = s.doc()?.target_parent()?;
     let id = s.edit("Graph", |d, sel| {
         let gid = d.alloc_id();
         let mut g = Node::group(gid, vec![]);

crates/engine/src/cmd/menucmds.rs

@@ -702,7 +702,7 @@ fn trim_marks(s: &mut Session, p: &Value) -> Result<Value> {
     if rects.is_empty() {
         return Err(bad(C, "nothing to mark"));
     }
-    let parent = s.doc()?.insertion_parent();
+    let parent = s.doc()?.target_parent()?;
     let ids = s.edit("Create Trim Marks", |d, sel| {
         let mut ids = vec![];
         for r in &rects {

crates/engine/src/cmd/mod.rs

@@ -324,6 +324,17 @@ pub(crate) fn checked_id(s: &Session, value: &Value, command: &str) -> Result<No
     Ok(id)
 }
 
+/// `v` as exactly `N` finite numbers (`[x, y]`, `[x, y, width, height]`…): `None` when it isn't an
+/// array of that length or an entry isn't a number, so nothing malformed is left out or padded.
+pub(crate) fn finite_numbers<const N: usize>(v: &Value) -> Option<[f64; N]> {
+    let a = v.as_array().filter(|a| a.len() == N)?;
+    let mut out = [0.0; N];
+    for (o, n) in out.iter_mut().zip(a) {
+        *o = n.as_f64().filter(|n| n.is_finite())?;
+    }
+    Some(out)
+}
+
 pub(crate) fn point_param(p: &Value, key: &str) -> Option<Point> {
     let a = p.get(key)?.as_array()?;
     Some(Point::new(a.first()?.as_f64()?, a.get(1)?.as_f64()?))

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/cmd/path.rs

@@ -129,7 +129,7 @@ fn path_mut(d: &mut vectorcraft_doc::Document, id: NodeId) -> Result<&mut PathDa
 
 fn append_anchor(s: &mut Session, p: &Value) -> Result<Value> {
     let id = id_param(p, "id").ok_or_else(|| bad("path.appendAnchor", "missing id"))?;
-    let a = anchor_from_json(p).ok_or_else(|| bad("path.appendAnchor", "missing x/y"))?;
+    let a = anchor_from_json(p, "path.appendAnchor")?;
     s.edit("Pen", |d, sel| {
         let path = path_mut(d, id)?;
         match path.subpaths.last_mut() {
@@ -217,12 +217,21 @@ fn set_anchors(s: &mut Session, p: &Value) -> Result<Value> {
     let data = PathData::new(
         subs.iter()
             .map(|sp| {
-                SubPath::new(
-                    sp.get("anchors").and_then(Value::as_array).map(|a| a.iter().filter_map(anchor_from_json).collect()).unwrap_or_default(),
-                    bool_or(sp, "closed", false),
-                )
+                let anchors = sp
+                    .get("anchors")
+                    .and_then(Value::as_array)
+                    .ok_or_else(|| bad("path.setAnchors", "each subpath needs an anchors array"))?
+                    .iter()
+                    .map(|a| anchor_from_json(a, "path.setAnchors"))
+                    .collect::<Result<Vec<_>>>()?;
+                let closed = match sp.get("closed") {
+                    None | Some(Value::Null) => false,
+                    Some(Value::Bool(v)) => *v,
+                    Some(_) => return Err(bad("path.setAnchors", "closed must be a boolean")),
+                };
+                Ok(SubPath::new(anchors, closed))
             })
-            .collect(),
+            .collect::<Result<Vec<_>>>()?,
     );
     s.edit("Reshape", |d, _| {
         *path_mut(d, id)? = data;

crates/engine/src/cmd/place/mod.rs

@@ -309,13 +309,22 @@ fn transformed(mut node: Node, m: Affine) -> Node {
 /// `[x, y, width, height]` with a positive size.
 fn rect_param(p: &Value) -> Result<Option<Rect>> {
     let Some(v) = p.get("rect") else { return Ok(None) };
-    let n: Vec<f64> = v.as_array().map(|a| a.iter().filter_map(Value::as_f64).collect()).unwrap_or_default();
-    match n[..] {
-        [x, y, w, h] if w > 0.0 && h > 0.0 => Ok(Some(Rect::new(x, y, x + w, y + h))),
+    // All four or nothing: a malformed entry dropped would shift the others ([0, "bad", 10, 40, 50]).
+    match finite_numbers(v) {
+        Some([x, y, w, h]) if w > 0.0 && h > 0.0 => Ok(Some(Rect::new(x, y, x + w, y + h))),
         _ => Err(bad(PLACE, "rect must be [x, y, width, height] with a positive width and height")),
     }
 }
 
+/// `at`, the `[x, y]` the art is centred on (absent or null: none); anything else fails rather than
+/// placing the art as if no point were given.
+fn at_param(p: &Value) -> Result<Option<Point>> {
+    p.get("at")
+        .filter(|v| !v.is_null())
+        .map(|v| finite_numbers(v).map(|[x, y]| Point::new(x, y)).ok_or_else(|| bad(PLACE, "at must be [x, y]")))
+        .transpose()
+}
+
 /// The transform that puts new art with the natural box `natural` where `old` is: an image's scale
 /// and rotation relative to its 100% size (its resolution's) and its centre are kept (with
 /// `image_xf`); other objects keep their centre.
@@ -342,7 +351,7 @@ fn fit(natural: Rect, r: Rect) -> Affine {
 fn place(s: &mut Session, p: &Value) -> Result<Value> {
     let replace = bool_or(p, "replace", false);
     let template = bool_or(p, "template", false);
-    let at = point_param(p, "at");
+    let at = at_param(p)?;
     let rect = rect_param(p)?;
     if replace && (template || at.is_some() || rect.is_some()) {
         return Err(bad(PLACE, "replace keeps the replaced object's place and transform: drop template, at and rect"));

crates/engine/src/cmd/rasterfx.rs

@@ -152,7 +152,8 @@ fn render(doc: &Document, nodes: Vec<Node>, region: Rect, scale: f64, anti_alias
     tmp.layers = vec![Arc::new(layer)];
     let mut r = vectorcraft_render::Renderer::new();
     r.threads = 0;
-    r.render_region_with(&tmp, region, scale, &RenderOptions { skip_templates: true, anti_alias, ..Default::default() })
+    // Art Optimized is supersampled, as in exports: shapes meeting edge to edge leave no seam.
+    r.render_region_with(&tmp, region, scale, &RenderOptions { skip_templates: true, anti_alias, supersample: true, ..Default::default() })
 }
 
 /// Pixels per point of raster effects rendered as images (the document's raster effects

crates/engine/src/cmd/select.rs

@@ -294,17 +294,35 @@ fn key(s: &mut Session, p: &Value) -> Result<Value> {
     ok()
 }
 
-/// `[[subpath, anchor]…]` anchor references (malformed entries are left out).
-pub(crate) fn parse_refs(v: Option<&Value>) -> Vec<(usize, usize)> {
-    v.and_then(Value::as_array)
-        .map(|a| a.iter().filter_map(|x| Some((x.get(0)?.as_u64()? as usize, x.get(1)?.as_u64()? as usize))).collect())
-        .unwrap_or_default()
+/// `[[subpath, anchor]…]` anchor references of `cmd`: a malformed entry fails rather than being
+/// left out, which would act on other anchors than the ones given.
+pub(crate) fn checked_refs(v: Option<&Value>, cmd: &str) -> Result<Vec<(usize, usize)>> {
+    let refs = v.and_then(Value::as_array).ok_or_else(|| bad(cmd, "`anchors` must be an array of [subpath, anchor] pairs"))?;
+    refs.iter()
+        .map(|v| {
+            let Some([subpath, anchor]) = v.as_array().map(Vec::as_slice) else {
+                return Err(bad(cmd, format!("invalid anchor reference {v}: expected [subpath, anchor]")));
+            };
+            let coordinate = |v: &Value| {
+                v.as_u64()
+                    .and_then(|n| usize::try_from(n).ok())
+                    .ok_or_else(|| bad(cmd, format!("invalid anchor index {v}: expected a non-negative integer")))
+            };
+            Ok((coordinate(subpath)?, coordinate(anchor)?))
+        })
+        .collect()
 }
 
 fn anchors(s: &mut Session, p: &Value) -> Result<Value> {
-    let id = id_param(p, "id").ok_or_else(|| bad("select.anchors", "missing id"))?;
-    let refs = parse_refs(p.get("anchors"));
-    let mode = str_param(p, "mode").unwrap_or("set").to_string();
+    const C: &str = "select.anchors";
+    let id = checked_id(s, p.get("id").ok_or_else(|| bad(C, "missing id"))?, C)?;
+    let refs = checked_refs(p.get("anchors"), C)?;
+    let mode = match str_param(p, "mode") {
+        None | Some("set") => "set",
+        Some("add") => "add",
+        Some("toggle") => "toggle",
+        Some(m) => return Err(bad(C, format!("unknown mode {m:?}"))),
+    };
     s.select(|_, sel| {
         if mode == "set" {
             sel.clear();
@@ -323,11 +341,16 @@ fn anchors(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 fn anchors_many(s: &mut Session, p: &Value) -> Result<Value> {
-    let items: Vec<(NodeId, BTreeSet<(usize, usize)>)> = p
-        .get("items")
-        .and_then(Value::as_array)
-        .map(|a| a.iter().filter_map(|it| Some((NodeId(it.get("id")?.as_u64()?), parse_refs(it.get("anchors")).into_iter().collect()))).collect())
-        .unwrap_or_default();
+    const C: &str = "select.anchorsMany";
+    let raw = p.get("items").and_then(Value::as_array).ok_or_else(|| bad(C, "`items` must be an array of {id, anchors}"))?;
+    let items: Vec<(NodeId, BTreeSet<(usize, usize)>)> = raw
+        .iter()
+        .map(|it| {
+            let id = checked_id(s, it.get("id").ok_or_else(|| bad(C, "each item needs an id"))?, C)?;
+            let refs = checked_refs(it.get("anchors"), C)?;
+            Ok((id, refs.into_iter().collect()))
+        })
+        .collect::<Result<_>>()?;
     // `add: true` is the older spelling of mode add.
     let mode = match str_param(p, "mode") {
         Some(m @ ("set" | "add" | "toggle" | "subtract")) => m,

crates/engine/src/cmd/stroke.rs

@@ -100,7 +100,12 @@ impl StrokeChange {
         let dash = match p.get("dash") {
             None => None,
             Some(Value::Null) => Some(None),
-            Some(Value::Array(a)) => Some(Some(a.iter().filter_map(Value::as_f64).collect::<Vec<_>>()).filter(|d| !d.is_empty())),
+            Some(Value::Array(a)) => {
+                // Do not silently omit malformed segments and change the user's dash pattern.
+                let values: Vec<f64> =
+                    a.iter().map(|v| v.as_f64().ok_or_else(|| bad(cmd, format!("dash lengths must be numbers, got {v}")))).collect::<Result<_>>()?;
+                Some(Some(values).filter(|d| !d.is_empty()))
+            }
             Some(v) => return Err(bad(cmd, format!("dash must be a list of lengths or null, got {v}"))),
         };
         Ok(Self {
@@ -167,9 +172,6 @@ fn no_targets(ids: &[vectorcraft_doc::NodeId], p: &Value) -> bool {
 fn stroke_set(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "stroke.set";
     let change = StrokeChange::parse(p, C)?;
-    if let Some(w) = change.weight {
-        s.paint.stroke_width = w;
-    }
     let item = item_target(s, p, C)?.of_kind(s, false);
     let mut ids = item.targets(s, p)?;
     let new_art = no_targets(&ids, p);
@@ -216,10 +218,6 @@ fn stroke_set(s: &mut Session, p: &Value) -> Result<Value> {
             st.profile = pr.clone();
         }
     };
-    // With nothing selected the Stroke panel sets up the next object drawn.
-    if new_art && let Some(st) = s.new_art_stroke_mut() {
-        set(st);
-    }
     edit_items(s, &ids, item, C, "Stroke", false, |n, index| {
         if index.is_none()
             && let NodeKind::Text(t) = &mut n.kind
@@ -235,6 +233,14 @@ fn stroke_set(s: &mut Session, p: &Value) -> Result<Value> {
         }
         Ok(())
     })?;
+    // Commit the new-art template only after the complete request is validated
+    // and the selected artwork edit has succeeded.
+    if let Some(w) = change.weight {
+        s.paint.stroke_width = w;
+    }
+    if new_art && let Some(st) = s.new_art_stroke_mut() {
+        set(st);
+    }
     ok()
 }
 

crates/engine/src/cmd/textedit.rs

@@ -45,7 +45,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Area / Path Type",
             [],
             None,
-            "{path: id, mode: \"area\"|\"onPath\", text?: \"\", vertical?: bool = false, at?: [x, y] (on-path start: nearest point), size?, font?, fit?: none|autoHeight|shrinkText, fitMinPercent? (area: as text.areaOptions; default autoHeight when the autoSizeAreaType preference is on), placeholder?: bool (placeholder text instead, as text.create), leadingModel?, charAlign? (as text.create)} turn a path into an area-type frame or a type-on-a-path baseline (the path's paint is dropped) → {id}",
+            "{path: id, mode: \"area\"|\"onPath\", text?: \"\", vertical?: bool = false, at?: [x, y] (on-path start: nearest point), size?, font?, style?, color? (as text.create), fit?: none|autoHeight|shrinkText, fitMinPercent? (area: as text.areaOptions; default autoHeight when the autoSizeAreaType preference is on), placeholder?: bool (placeholder text instead, as text.create), leadingModel?, charAlign? (as text.create)} turn a path into an area-type frame or a type-on-a-path baseline (the path's paint is dropped) → {id}",
             has_doc,
             create_in_path
         ),
@@ -485,16 +485,7 @@ fn create_in_path(s: &mut Session, p: &Value) -> Result<Value> {
     if !on_path && !path.is_closed() && path.bounds().is_none_or(|b| b.width() < 1.0 || b.height() < 1.0) {
         return Err(bad(C, "area type needs a path that encloses an area"));
     }
-    let mut style = CharStyle::default();
-    if let Some(v) = p.get("size").and_then(Value::as_f64) {
-        style.size = v.clamp(0.1, 1296.0);
-    }
-    if let Some(f) = str_param(p, "font") {
-        style.font_family = f.to_string();
-    }
-    if !s.paint.fill.is_none() && s.paint.fill != Paint::solid(vectorcraft_color::Color::WHITE) {
-        style.fill = s.paint.fill.clone();
-    }
+    let style = super::create::new_type_style(s, p);
     let text = str_param(p, "text").unwrap_or("").to_string();
     let start = match point_param(p, "at") {
         Some(at) if on_path => vectorcraft_geom::ArcPath::new(path).fraction_at(at).unwrap_or(0.0),

crates/engine/src/cmd/textstyles.rs

@@ -133,14 +133,44 @@ fn to_attrs<T: Serialize>(v: &T) -> Map<String, Value> {
     m
 }
 
+/// Every attribute name `T` reads, including those its JSON leaves out at their defaults (Auto
+/// leading and kerning, no mojikumi…): the field names serde's derive hands `deserialize_struct`.
+/// Not `justify_auto`, which [`to_map`] turns into `"justify": "Auto"`.
+fn attr_names<T: DeserializeOwned>() -> Vec<&'static str> {
+    use serde::de::{Error as _, Visitor, value::Error};
+
+    struct Names<'a>(&'a mut &'static [&'static str]);
+    impl<'de> serde::Deserializer<'de> for Names<'_> {
+        type Error = Error;
+        fn deserialize_any<V: Visitor<'de>>(self, _: V) -> std::result::Result<V::Value, Error> {
+            Err(Error::custom("not a struct"))
+        }
+        fn deserialize_struct<V: Visitor<'de>>(self, _: &'static str, fields: &'static [&'static str], _: V) -> std::result::Result<V::Value, Error> {
+            *self.0 = fields;
+            Err(Error::custom("field names only"))
+        }
+        serde::forward_to_deserialize_any! {
+            bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string bytes byte_buf option unit
+            unit_struct newtype_struct seq tuple tuple_struct map enum identifier ignored_any
+        }
+    }
+
+    let mut fields: &'static [&'static str] = &[];
+    // Always an error: the probe only records the names.
+    let _ = T::deserialize(Names(&mut fields));
+    fields.iter().copied().filter(|&f| f != "justify_auto").collect()
+}
+
 /// `base` with `attrs` written over it (unknown or ill-typed attributes are an error).
 fn with_attrs<T: Serialize + DeserializeOwned>(base: &T, attrs: &Map<String, Value>, cmd: &str) -> Result<T> {
     let mut m = to_attrs(base);
     if let Some(full) = to_map(base) {
         m.insert("style_name".into(), full.get("style_name").cloned().unwrap_or(Value::Null));
     }
+    let names = attr_names::<T>();
     for (k, v) in attrs {
-        if !m.contains_key(k) {
+        // Not only the keys `base` writes: those at their defaults (Auto leading…) are left out.
+        if !m.contains_key(k) && !names.contains(&k.as_str()) {
             return Err(bad(cmd, format!("unknown attribute `{k}`")));
         }
         m.insert(k.clone(), v.clone());
@@ -575,6 +605,44 @@ mod tests {
         assert_eq!(s.doc().unwrap().doc.char_styles.iter().find(|d| d.name == "Pink").unwrap().attrs["fill"], fill);
     }
 
+    /// #1001: attributes their JSON leaves out at the defaults (Auto leading and kerning, no
+    /// mojikumi) are still attributes a style can set, and a style captured with one applies to
+    /// text at the default, is duplicated and comes back out of a library.
+    #[test]
+    fn styles_take_attributes_left_out_at_their_defaults() {
+        let (mut s, id) = session_with_text("A");
+        s.execute("charStyle.new", &json!({"name": "Kerned", "attrs": {"kerning": 40, "leading": 30}})).unwrap();
+        s.execute("charStyle.setAttrs", &json!({"name": "Kerned", "attrs": {"kerning": 20, "small_caps": 70}})).unwrap();
+        s.execute("paraStyle.new", &json!({"name": "Punctuation", "attrs": {"mojikumi": "lineEndHalf"}})).unwrap();
+        s.execute("paraStyle.setAttrs", &json!({"name": "Punctuation", "attrs": {"direction": "rightToLeft"}})).unwrap();
+        for bad in [json!({"nope": 1}), json!({"justify_auto": true})] {
+            assert!(s.execute("paraStyle.new", &json!({"name": "Bad", "attrs": bad})).is_err(), "{bad}");
+        }
+        // Captured from text with explicit leading, applied to fresh Auto-leading text.
+        s.execute("text.setStyle", &json!({"leading": 30})).unwrap();
+        s.execute("charStyle.new", &json!({"name": "Spaced"})).unwrap();
+        let fresh = s.execute("text.create", &json!({"x": 10, "y": 90, "text": "B"})).unwrap()["id"].as_u64().unwrap();
+        assert_eq!(runs(&s, fresh)[0].style.leading, None);
+        for clear in [false, true] {
+            s.execute("charStyle.apply", &json!({"name": "Spaced", "id": fresh, "clearOverrides": clear})).unwrap();
+            assert_eq!(runs(&s, fresh)[0].style.leading, Some(30.0));
+        }
+        let copy = s.execute("charStyle.duplicate", &json!({"name": "Spaced"})).unwrap()["name"].as_str().unwrap().to_string();
+        assert_eq!(s.doc().unwrap().doc.char_styles.iter().find(|d| d.name == copy).unwrap().attrs["leading"], 30.0);
+        s.execute("charStyle.apply", &json!({"name": "Kerned", "id": fresh})).unwrap();
+        let st = runs(&s, fresh)[0].style.clone();
+        assert_eq!((st.kerning, st.small_caps), (Some(20.0), Some(70.0)));
+        s.execute("paraStyle.apply", &json!({"name": "Punctuation", "id": id})).unwrap();
+        let NodeKind::Text(t) = &s.doc().unwrap().doc.node(NodeId(id)).unwrap().kind else { panic!() };
+        assert_eq!((t.para.mojikumi, t.para.direction), (vectorcraft_doc::Mojikumi::LineEndHalf, Some(vectorcraft_doc::ParaDirection::RightToLeft)));
+        // A library keeps the captured attributes and makes the style again where it's used.
+        s.execute("select.set", &json!({"ids": [id]})).unwrap();
+        let lib = s.execute("library.add", &json!({"kind": "charStyle", "name": "Lib Spaced"})).unwrap();
+        let other = s.execute("text.create", &json!({"x": 10, "y": 150, "text": "C"})).unwrap()["id"].as_u64().unwrap();
+        s.execute("library.use", &json!({"library": lib["library"], "kind": "charStyle", "item": lib["name"]})).unwrap();
+        assert_eq!(runs(&s, other)[0].style.leading, Some(30.0));
+    }
+
     #[test]
     fn paragraph_styles_and_survive_save() {
         let (mut s, id) = session_with_text("Body");

crates/engine/src/cmd/typecmd.rs

@@ -628,7 +628,7 @@ fn area_options(s: &mut Session, p: &Value) -> Result<Value> {
 fn reshape_area(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "text.reshapeArea";
     let id = id_param(p, "id").ok_or_else(|| bad(C, "missing id"))?;
-    let mut refs = super::select::parse_refs(p.get("anchors"));
+    let mut refs = super::select::checked_refs(p.get("anchors"), C)?;
     refs.sort_unstable();
     refs.dedup();
     if refs.is_empty() {

crates/engine/src/cmd/webexport.rs

@@ -582,8 +582,14 @@ pub fn render(doc: &Document, s: &WebSettings) -> std::result::Result<WebRender,
     let doc = doc.without_edit_modes();
     let (region, scale) = region(&doc, s)?;
     let page = (doc.setup.background == vectorcraft_doc::Background::White).then_some([255; 4]);
-    let opts =
-        vectorcraft_render::RenderOptions { background: page, skip_templates: true, anti_alias: s.anti_alias, precise: true, ..Default::default() };
+    let opts = vectorcraft_render::RenderOptions {
+        background: page,
+        skip_templates: true,
+        anti_alias: s.anti_alias,
+        precise: true,
+        supersample: true,
+        ..Default::default()
+    };
     let img = vectorcraft_render::Renderer::new().render_region_with(&doc, region, scale, &opts);
     Ok(WebRender { rgba: img.to_straight(), width: img.width, height: img.height, region, scale })
 }

crates/engine/src/cmd/xform.rs

@@ -132,32 +132,29 @@ fn warp_node(n: &mut Node, pr: &Projective) {
 }
 
 fn distort(s: &mut Session, p: &Value) -> Result<Value> {
-    let corners: Vec<Point> = p
+    const C: &str = "object.distort";
+    // All four corners or nothing, each exactly [x, y]: nothing malformed is left out.
+    let corners: Option<Vec<Point>> = p
         .get("corners")
         .and_then(Value::as_array)
-        .map(|a| a.iter().filter_map(|c| Some(Point::new(c.get(0)?.as_f64()?, c.get(1)?.as_f64()?))).collect())
-        .unwrap_or_default();
-    if corners.len() != 4 {
-        return Err(bad("object.distort", "corners must be 4 [x,y] points (TL, TR, BR, BL)"));
+        .filter(|a| a.len() == 4)
+        .and_then(|a| a.iter().map(|c| finite_numbers(c).map(|[x, y]| Point::new(x, y))).collect());
+    let Some(&[tl, tr, br, bl]) = corners.as_deref() else { return Err(bad(C, "corners must be 4 [x, y] points (TL, TR, BR, BL)")) };
+    let ids = if p.get("ids").is_some_and(|v| !v.is_null()) { checked_ids_param(s, p, "ids", C)? } else { selected_roots(s)? };
+    if ids.is_empty() {
+        return Err(bad(C, "nothing to distort"));
     }
-    let ids = match ids_param(p, "ids") {
-        Some(v) => v,
-        None => selected_roots(s)?,
-    };
-    let src = match p.get("from").and_then(Value::as_array) {
-        Some(a) if a.len() == 4 => {
-            let f: Vec<f64> = a.iter().filter_map(Value::as_f64).collect();
-            if f.len() != 4 {
-                return Err(bad("object.distort", "from must be [x0,y0,x1,y1]"));
-            }
-            Rect::new(f[0], f[1], f[2], f[3])
+    let src = match p.get("from").filter(|v| !v.is_null()) {
+        None => s.doc()?.doc.bounds_of(&ids, false).ok_or_else(|| bad(C, "nothing to distort"))?,
+        Some(v) => {
+            let [x0, y0, x1, y1] = finite_numbers(v).ok_or_else(|| bad(C, "from must be [x0, y0, x1, y1]"))?;
+            Rect::new(x0, y0, x1, y1)
         }
-        _ => s.doc()?.doc.bounds_of(&ids, false).ok_or_else(|| EngineError::Other("nothing to distort".into()))?,
     };
-    if src.width().abs() < 1e-9 || src.height().abs() < 1e-9 {
-        return Err(EngineError::Other("cannot distort a zero-size bounding box".into()));
+    if !src.width().is_finite() || !src.height().is_finite() || src.width().abs() < 1e-9 || src.height().abs() < 1e-9 {
+        return Err(bad(C, "cannot distort a zero-size or non-finite bounding box"));
     }
-    let pr = Projective::from_rect(src, [corners[0], corners[1], corners[2], corners[3]]);
+    let pr = Projective::from_rect(src, [tl, tr, br, bl]);
     s.edit("Free Distort", |d, _| {
         for id in &ids {
             if let Some(n) = d.node_mut(*id) {

crates/engine/src/lib.rs

@@ -346,6 +346,14 @@ impl DocState {
         // A sublayer takes new art only while it and the layers around it are shown and unlocked.
         self.active_layer.filter(|l| self.doc.node(*l).is_some_and(|n| n.is_layer()) && self.doc.is_editable(*l)).or_else(|| self.doc.default_layer())
     }
+    /// [`Self::insertion_parent`] for new art, which a locked or hidden layer never takes: an error
+    /// when no layer is shown and unlocked, so the art is refused rather than hidden or locked away.
+    pub fn target_parent(&self) -> Result<Option<NodeId>> {
+        match self.insertion_parent() {
+            Some(p) if !self.doc.is_editable(p) => Err(EngineError::Other("the target layer is locked or hidden".into())),
+            parent => Ok(parent),
+        }
+    }
     /// The highlighted Layers panel rows that still exist (ids are reused after undo, so a
     /// remembered row must still be in the document).
     pub fn highlighted_rows(&self) -> Vec<NodeId> {

crates/engine/src/tests.rs

@@ -134,6 +134,74 @@ fn fill_and_stroke_commands() {
     s.execute("paint.setFill", &json!({"gradient": {"kind": "radial"}})).unwrap();
 }
 
+#[test]
+fn stroke_rejects_invalid_dash_components_and_preserves_defaults_on_error() {
+    let mut s = session();
+    let id = rect(&mut s, 0.0, 0.0, 40.0, 30.0);
+    s.execute("stroke.set", &json!({"weight": 3, "dash": [6, 3]})).unwrap();
+    let previous_weight = s.paint.stroke_width;
+    let previous_stroke = s.doc().unwrap().doc.node(id).unwrap().appearance.stroke().cloned();
+
+    for params in [
+        json!({"weight": 10, "dash": [6, "not a number", 3]}),
+        json!({"weight": 10, "ids": "not an array"}),
+        json!({"weight": 10, "item": "invalid"}),
+        json!({"weight": 10, "arrowAlign": "unknown"}),
+    ] {
+        assert!(s.execute("stroke.set", &params).is_err(), "{params} must fail");
+        assert_eq!(s.paint.stroke_width, previous_weight, "failed stroke edit changed new-art defaults");
+        assert_eq!(s.doc().unwrap().doc.node(id).unwrap().appearance.stroke().cloned(), previous_stroke);
+    }
+
+    // A valid dash list still updates the selected stroke and new-art default width.
+    s.execute("stroke.set", &json!({"weight": 7, "dash": [4, 2]})).unwrap();
+    assert_eq!(s.paint.stroke_width, 7.0);
+    assert_eq!(s.doc().unwrap().doc.node(id).unwrap().appearance.stroke().unwrap().width, 7.0);
+
+    // With nothing selected the panel sets up the next object drawn: a rejected edit doesn't.
+    s.execute("select.none", &json!({})).unwrap();
+    let next = s.new_art();
+    assert!(s.execute("stroke.set", &json!({"weight": 12, "dash": [2, 2], "arrowAlign": "unknown"})).is_err());
+    assert_eq!(s.new_art(), next);
+    s.execute("stroke.set", &json!({"weight": 12, "dash": [2, 2]})).unwrap();
+    let next = s.new_art();
+    let stroke = next.stroke().unwrap();
+    assert_eq!((stroke.width, stroke.dash.as_ref().map(|d| d.pattern.clone())), (12.0, Some(vec![2.0, 2.0])));
+}
+
+#[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();
@@ -892,3 +960,66 @@ fn given_targets_are_used_as_given_and_range_style_takes_the_selected_type() {
     assert!(s.execute("text.setRangeStyle", &json!({"start": 0, "end": 3, "size": 40})).is_err(), "two type objects: which one?");
     assert!(s.execute("text.setRangeStyle", &json!({"id": "two", "size": 40})).is_err());
 }
+
+#[test]
+fn malformed_anchor_selection_never_replaces_or_partially_changes_selection() {
+    let mut s = session();
+    let a = rect(&mut s, 10.0, 10.0, 30.0, 20.0);
+    let b = rect(&mut s, 50.0, 10.0, 30.0, 20.0);
+    let expected = s.doc().unwrap().selection.objects.clone();
+    let expected_anchors = s.doc().unwrap().selection.anchors.clone();
+    for p in [
+        json!({"id": a.0, "anchors": [[0, 0], ["bad", 2]]}),
+        json!({"id": a.0, "anchors": [[0, 0, 1]]}),
+        json!({"id": a.0, "anchors": "not an array"}),
+        json!({"id": u64::MAX, "anchors": []}),
+        json!({"id": a.0, "anchors": [], "mode": "missing"}),
+    ] {
+        assert!(s.execute("select.anchors", &p).is_err(), "{p}");
+        assert_eq!(s.doc().unwrap().selection.objects, expected);
+        assert_eq!(s.doc().unwrap().selection.anchors, expected_anchors);
+    }
+    for p in [
+        json!({"items": [{"id": a.0, "anchors": [[0, 0]]}, {"id": b.0, "anchors": [[0, "bad"]]}]}),
+        json!({"items": [{"id": a.0, "anchors": [[0, 0]]}, {"id": "bad", "anchors": [[0, 0]]}]}),
+        json!({"items": [{"id": u64::MAX, "anchors": []}]}),
+        json!({"items": [{"id": a.0}]}),
+    ] {
+        assert!(s.execute("select.anchorsMany", &p).is_err(), "{p}");
+        assert_eq!(s.doc().unwrap().selection.objects, expected);
+        assert_eq!(s.doc().unwrap().selection.anchors, expected_anchors);
+    }
+    s.execute("select.anchorsMany", &json!({"items": [{"id": a.0, "anchors": [[0, 0]]}]})).unwrap();
+    assert!(s.doc().unwrap().selection.contains(a));
+    assert!(!s.doc().unwrap().selection.contains(b));
+}
+
+#[test]
+fn path_commands_reject_bad_anchors_before_modifying_geometry() {
+    let mut s = session();
+    let a = rect(&mut s, 10.0, 20.0, 50.0, 30.0);
+    let original_points: Vec<_> = s.doc().unwrap().doc.node(a).unwrap().path_data().unwrap().anchors().map(|(_, _, an)| an.p).collect();
+    let history = s.doc().unwrap().history.undo.len();
+    let valid = json!({"x": 10, "y": 20});
+    for invalid in [
+        json!({"x": "bad", "y": 40}),
+        json!({"x": 50}),
+        json!({"x": 50, "y": 40, "in": [0]}),
+        json!({"x": 50, "y": 40, "out": [1, "bad"]}),
+        json!({"x": 50, "y": 40, "smooth": "yes"}),
+    ] {
+        let anchors = json!([valid.clone(), invalid]);
+        assert!(s.execute("path.create", &json!({"anchors": anchors})).is_err(), "{anchors}");
+        assert!(s.execute("path.setAnchors", &json!({"id": a.0, "subpaths": [{"anchors": anchors}]})).is_err(), "{anchors}");
+        let points: Vec<_> = s.doc().unwrap().doc.node(a).unwrap().path_data().unwrap().anchors().map(|(_, _, an)| an.p).collect();
+        assert_eq!(points, original_points);
+        assert_eq!(s.doc().unwrap().history.undo.len(), history);
+    }
+    assert!(s.execute("path.setAnchors", &json!({"id": a.0, "subpaths": [{"anchors": []}, {"closed": true}]})).is_err());
+    assert!(s.execute("path.setAnchors", &json!({"id": a.0, "subpaths": [{"anchors": [valid.clone()], "closed": "yes"}]})).is_err());
+    // The Pen's append reads its anchor the same way.
+    assert!(s.execute("path.appendAnchor", &json!({"id": a.0, "x": 5, "y": 5, "out": [1]})).is_err());
+    assert_eq!(s.doc().unwrap().history.undo.len(), history);
+    s.execute("path.setAnchors", &json!({"id": a.0, "subpaths": [{"anchors": [{"x": 0, "y": 0}, {"x": 30, "y": 40}], "closed": false}]})).unwrap();
+    assert_eq!(s.doc().unwrap().doc.node(a).unwrap().path_data().unwrap().anchor_count(), 2);
+}

crates/engine/src/tests_assets.rs

@@ -265,3 +265,21 @@ fn assets_export_into_a_folder() {
     assert!(dir.join("2x/Logo@2x.png").is_file() && dir.join("PDF/Logo.pdf").is_file());
     let _ = std::fs::remove_dir_all(&dir);
 }
+
+#[test]
+fn collecting_explicit_assets_rejects_invalid_ids_without_adding_anything() {
+    let mut s = session();
+    let a = rect(&mut s, 10.0, 10.0, 20.0, 20.0);
+    let b = rect(&mut s, 50.0, 10.0, 20.0, 20.0);
+    let original_selection = s.doc().unwrap().selection.objects.clone();
+    let before = undo_len(&s);
+    for ids in [json!([a, "not an object"]), json!([a, 3.5]), json!([a, u64::MAX]), json!({"id": a})] {
+        assert!(s.execute("assets.add", &json!({"ids": ids})).is_err(), "invalid ids: {ids}");
+        assert!(assets(&mut s).is_empty(), "invalid ids must not collect only the valid subset");
+        assert_eq!(undo_len(&s), before);
+        assert_eq!(s.doc().unwrap().selection.objects, original_selection);
+    }
+    // Valid ids still collect art in document paint order.
+    assert_eq!(run(&mut s, "assets.add", json!({"ids": [b, a]}))["added"], 2);
+    assert_eq!(assets(&mut s).len(), 2);
+}

crates/engine/src/tests_cut.rs

@@ -118,6 +118,24 @@ fn line_cut_that_misses_changes_nothing() {
     assert!(s.execute("path.lineCut", &json!({"from": [5, 5]})).is_err());
 }
 
+#[test]
+fn rect_cut_rejects_non_numeric_rectangle_elements_without_modifying_art() {
+    let mut s = session();
+    let id = rect(&mut s, 0.0, 0.0, 100.0, 100.0);
+    select(&mut s, &[id]);
+    let original = bounds(&s, id);
+    let history = undo_depth(&s);
+    // The old parser dropped the string and used the four remaining values.
+    for params in [json!([0, "ignored", 10, 50, 50]), json!([0, 10, 50, null, 50]), json!([0, 10, 50, 50, 5])] {
+        assert!(s.execute("path.rectCut", &json!({"rect": params})).is_err());
+        assert!(near(bounds(&s, id), original), "failed cut must not change geometry");
+        assert_eq!(undo_depth(&s), history, "failed cut must not add undo history");
+    }
+    // Proper rectangular cuts still work.
+    s.execute("path.rectCut", &json!({"rect": [10, 10, 70, 70]})).unwrap();
+    assert!(near(bounds(&s, id), Rect::new(10.0, 10.0, 80.0, 80.0)));
+}
+
 #[test]
 fn rect_cut_crops_to_real_geometry() {
     let mut s = session();

crates/engine/src/tests_layers.rs

@@ -78,6 +78,36 @@ fn art_in_a_sublayer_is_selected_as_objects_not_the_sublayer() {
     assert!(s.doc().unwrap().doc.node(a).is_none());
 }
 
+/// #1002: with no layer shown and unlocked, new art is refused (the document unchanged) rather
+/// than put on a hidden or locked layer; another layer that takes art still gets it.
+#[test]
+fn new_art_is_refused_when_no_layer_is_shown_and_unlocked() {
+    for prop in ["visible", "locked"] {
+        let mut s = session();
+        let layer = s.doc().unwrap().doc.layers[0].id;
+        let copied = rect(&mut s, 0.0);
+        run(&mut s, "select.set", json!({"ids": [copied.0]}));
+        run(&mut s, "edit.copy", json!({}));
+        run(&mut s, "select.none", json!({}));
+        run(&mut s, "layer.setProps", json!({"ids": [layer.0], prop: prop == "locked"}));
+        let before = s.doc().unwrap().doc.clone();
+        for (cmd, p) in [
+            ("shape.ellipse", json!({"x": 10, "y": 10, "width": 20, "height": 20})),
+            ("shape.polarGrid", json!({"x": 10, "y": 10, "width": 20, "height": 20})),
+            ("text.create", json!({"x": 10, "y": 40, "text": "A"})),
+            ("edit.paste", json!({})),
+        ] {
+            let e = s.execute(cmd, &p).unwrap_err();
+            assert_eq!(e.to_string(), "the target layer is locked or hidden", "{prop} {cmd}");
+        }
+        assert_eq!(s.doc().unwrap().doc.layers, before.layers, "{prop}: nothing was added");
+        let other = id(&run(&mut s, "layer.new", json!({})));
+        run(&mut s, "layer.setCurrent", json!({"id": layer.0}));
+        let n = rect(&mut s, 50.0);
+        assert_eq!(parent(&s, n), Some(other), "{prop}");
+    }
+}
+
 #[test]
 fn clicking_rows_at_any_depth_highlights_them_and_sets_the_current_layer() {
     let mut s = session();

crates/engine/src/tests_panelcmds.rs

@@ -56,6 +56,13 @@ fn edit_gradient_angle_reverse_and_errors() {
     s.execute("paint.editGradient", &json!({"stroke": false, "reverse": true})).unwrap();
     let Paint::Gradient(g) = node(&s, id).appearance.fill_paint() else { panic!() };
     assert_eq!(g.gradient.stops[0].color.to_hex(), "#000000");
+    // #1007: an off-centre midpoint is mirrored, not reset.
+    let stops = json!([{"offset": 0, "color": "#ff0000", "midpoint": 0.2}, {"offset": 1, "color": "#0000ff"}]);
+    s.execute("paint.editGradient", &json!({"stroke": false, "stops": stops})).unwrap();
+    s.execute("paint.editGradient", &json!({"stroke": false, "reverse": true})).unwrap();
+    let Paint::Gradient(g) = node(&s, id).appearance.fill_paint() else { panic!() };
+    assert_eq!(g.gradient.stops[0].color.to_hex(), "#0000ff");
+    assert!((g.gradient.stops[0].midpoint - 0.8).abs() < 1e-6, "{:?}", g.gradient.stops);
     assert!(s.execute("paint.editGradient", &json!({"stops": [{"offset": 0, "color": "#fff"}]})).is_err());
     assert!(s.execute("paint.editGradient", &json!({"kind": "conic"})).is_err());
 }

crates/engine/src/tests_place.rs

@@ -57,6 +57,37 @@ fn serialize(s: &mut Session, format: &str) -> Vec<u8> {
     vectorcraft_format::base64_decode(v["dataBase64"].as_str().unwrap()).unwrap()
 }
 
+#[test]
+fn malformed_place_coordinates_are_rejected_instead_of_silently_changed() {
+    let mut s = session();
+    let png = png(4, 2, [20, 40, 60, 255], None);
+    let original = s.doc().unwrap().doc.layers.clone();
+    // Previously filter_map dropped the string from a five-element rectangle and
+    // treated the remaining four values as a different, valid placement.
+    for rect in [json!([0, "ignored", 10, 40, 50]), json!([10, 20, 40, null, 50]), json!([10, 20, 40, 50, 60])] {
+        let mut params = file("tiny.png", &png);
+        params["rect"] = rect;
+        assert!(s.execute("file.place", &params).is_err(), "{params}");
+        assert_eq!(s.doc().unwrap().doc.layers, original, "failed Place must not add art");
+    }
+    // An explicitly supplied invalid position formerly behaved as though no
+    // position were supplied and centred the image on the artboard.
+    for at in [json!(["not-a-number", 20]), json!([10, null]), json!([10, 20, 30]), json!("invalid")] {
+        let mut params = file("tiny.png", &png);
+        params["at"] = at;
+        assert!(s.execute("file.place", &params).is_err(), "{params}");
+        assert_eq!(s.doc().unwrap().doc.layers, original);
+    }
+    let mut params = file("tiny.png", &png);
+    params["rect"] = json!([10, 20, 80, 60]);
+    let placed = s.execute("file.place", &params).unwrap();
+    assert_eq!(placed["ids"].as_array().unwrap().len(), 1);
+    // A null position is no position, as for the other optional params.
+    let mut params = file("tiny.png", &png);
+    params["at"] = Value::Null;
+    assert_eq!(s.execute("file.place", &params).unwrap()["ids"].as_array().unwrap().len(), 1);
+}
+
 #[test]
 fn a_300_px_png_at_300_ppi_places_as_72_pt_centred_selected_and_undoable() {
     let mut s = session();

crates/engine/src/tests_typearea.rs

@@ -236,6 +236,9 @@ fn reshape_area_takes_untrusted_params() {
         json!({"id": id.0, "dx": 1, "dy": 1}),
         json!({"id": id.0, "anchors": [], "dx": 1, "dy": 1}),
         json!({"id": id.0, "anchors": [["a", 1], [0], "x"], "dx": 1, "dy": 1}),
+        // A malformed reference among good ones fails rather than moving only the good ones.
+        json!({"id": id.0, "anchors": [[0, 2], [0, "3"]], "dx": 1, "dy": 1}),
+        json!({"id": id.0, "anchors": [[0, 2], [0, 3, 1]], "dx": 1, "dy": 1}),
         json!({"id": id.0, "anchors": [[0, 9]], "dx": 1, "dy": 1}),
         json!({"id": id.0, "anchors": [[0, 1], [7, 0]], "dx": 1, "dy": 1}),
         json!({"id": id.0, "anchors": [[0, 2]], "dy": 1}),

crates/engine/src/tests_xform.rs

@@ -572,3 +572,27 @@ fn copy_from_requires_source() {
     assert!(s.execute("appearance.copyFrom", &json!({})).is_err());
     assert!(s.execute("appearance.copyFrom", &json!({"source": 9999})).is_err());
 }
+
+#[test]
+fn distort_rejects_malformed_coordinates_and_ids_without_editing_art() {
+    let mut s = session();
+    let a = rect(&mut s, 0.0, 0.0, 100.0, 100.0);
+    let original = bounds(&s, a);
+    let history = undo_len(&s);
+    let corners = json!([[10, 0], [90, 0], [100, 100], [0, 100]]);
+    for p in [
+        json!({"corners": [[10, 0, 50], [90, 0], [100, 100], [0, 100]]}),
+        json!({"corners": [[10, 0], [90, 0], ["bad", 100], [0, 100]]}),
+        json!({"corners": [[10, 0], [90, 0], [100, 100], [0, 100], ["bad"]]}),
+        json!({"corners": corners, "from": [0, 0, 100]}),
+        json!({"corners": corners, "from": "not bounds"}),
+        json!({"corners": corners, "ids": [a.0, "bad"]}),
+        json!({"corners": corners, "ids": [a.0, u64::MAX]}),
+    ] {
+        assert!(s.execute("object.distort", &p).is_err(), "invalid input: {p}");
+        assert!(close(bounds(&s, a), original));
+        assert_eq!(undo_len(&s), history);
+    }
+    s.execute("object.distort", &json!({"corners": corners, "from": [0, 0, 100, 100], "ids": [a.0]})).unwrap();
+    assert_eq!(undo_len(&s), history + 1);
+}

crates/mcp/src/tests.rs

@@ -312,6 +312,22 @@ fn inspect_document_reports_the_paint_of_type() {
     assert_eq!((t["fill"].as_str(), t["stroke"].as_str(), t["strokeWidth"].as_f64()), (Some("#0000ff"), Some("#00ff00"), Some(3.0)), "{t}");
 }
 
+/// #1003: type made on or in a path takes add_text's `color` too, over the current fill.
+#[test]
+fn add_text_on_or_in_a_path_takes_its_color() {
+    for mode in ["onPath", "area"] {
+        let mut s = server();
+        let r = call(&mut s, 2, "draw_shape", json!({"shape": "rectangle", "x": 40, "y": 40, "width": 180, "height": 60, "fill": "#0000ff"}));
+        let path = serde_json::from_str::<Value>(&text_of(&r)).unwrap()["id"].clone();
+        let r = call(&mut s, 3, "add_text", json!({"text": "Hello", "path": path, "mode": mode, "color": "#ff0000"}));
+        assert_eq!(r["isError"], false, "{r}");
+        let id = serde_json::from_str::<Value>(&text_of(&r)).unwrap()["id"].clone();
+        let v: Value = serde_json::from_str(&text_of(&call(&mut s, 4, "inspect_document", json!({})))).unwrap();
+        let t = v["layers"][0]["children"].as_array().unwrap().iter().find(|c| c["id"] == id).cloned().unwrap();
+        assert_eq!(t["fill"].as_str(), Some("#ff0000"), "{mode}: {t}");
+    }
+}
+
 /// save_file says it saves in the document's own format or the one the path's extension picks.
 #[test]
 fn save_file_describes_the_formats_it_writes() {

crates/mcp/src/tools.rs

@@ -574,7 +574,7 @@ fn select_ids(b: &mut dyn Backend, a: &Args) -> Result<(), String> {
 fn add_text(b: &mut dyn Backend, a: &Args) -> Result<Value, String> {
     let text = a.get("text").and_then(Value::as_str).ok_or("missing string argument `text`")?;
     let mut style = json!({});
-    for k in ["size", "font"] {
+    for k in ["size", "font", "color"] {
         if let Some(v) = a.get(k) {
             style[k] = v.clone();
         }
@@ -592,9 +592,6 @@ fn add_text(b: &mut dyn Backend, a: &Args) -> Result<Value, String> {
         for (k, v) in style.as_object().into_iter().flatten() {
             p[k.as_str()] = v.clone();
         }
-        if let Some(c) = a.get("color") {
-            p["color"] = c.clone();
-        }
         if let (Some(w), Some(h)) = (a.get("width"), a.get("height")) {
             p["area"] = json!({"width": w, "height": h});
         }

crates/render/src/encode/mod.rs

@@ -97,6 +97,8 @@ impl RasterExportOptions {
             anti_alias: self.anti_alias,
             // Opaque art stays exactly opaque where translucent edges cross it (#787).
             precise: true,
+            // Shapes meeting edge to edge leave no seam (#983).
+            supersample: true,
             ..Default::default()
         }
     }

crates/render/src/lib.rs

@@ -114,6 +114,11 @@ pub struct RenderOptions {
     /// opaque, where 8-bit compositing leaves alpha 254 on some anti-aliased edges (#787). Off,
     /// the faster 8-bit pipeline (the canvas).
     pub precise: bool,
+    /// Exports: Art Optimized edges are supersampled ([`supersample_factor`]): the art is drawn
+    /// with hard edges at several times the size and averaged down, so shapes that meet edge to
+    /// edge leave no seam of the background between them (#983). Off, edges are smoothed shape by
+    /// shape (the canvas).
+    pub supersample: bool,
 }
 
 /// The opacity of the art around an isolated group or layer.
@@ -186,10 +191,48 @@ impl Default for RenderOptions {
             smooth_images: true,
             isolated: None,
             precise: false,
+            supersample: false,
         }
     }
 }
 
+/// The most pixels a supersampled render draws (the frame and its compositing buffers hold a few
+/// times this many bytes).
+const MAX_SUPERSAMPLED_PIXELS: u64 = 40_000_000;
+
+/// How many times wider and taller a `w`×`h` render is drawn when supersampled: 4, or less where
+/// that would pass [`MAX_SUPERSAMPLED_PIXELS`] or the renderer's 65,535-pixel side; `None` when not
+/// even twice fits (the edges are then smoothed shape by shape).
+pub fn supersample_factor(w: u32, h: u32) -> Option<u32> {
+    (2..=4u32).rev().find(|k| {
+        let (sw, sh) = (u64::from(w) * u64::from(*k), u64::from(h) * u64::from(*k));
+        sw <= u64::from(u16::MAX) && sh <= u64::from(u16::MAX) && sw * sh <= MAX_SUPERSAMPLED_PIXELS
+    })
+}
+
+/// Average each `k`×`k` block of `src` (`w`×`h` pixels of 4 premultiplied bytes) into one pixel.
+fn downsample(src: &[u8], w: usize, h: usize, k: usize) -> Vec<u8> {
+    let (ow, oh) = (w / k.max(1), h / k.max(1));
+    let n = (k * k).max(1) as u32;
+    let mut out = vec![0u8; ow * oh * 4];
+    for (o, px) in out.as_chunks_mut::<4>().0.iter_mut().enumerate() {
+        let (ox, oy) = (o % ow.max(1), o / ow.max(1));
+        let mut acc = [0u32; 4];
+        for y in oy * k..(oy + 1) * k {
+            let row = y * w + ox * k;
+            for p in src.get(row * 4..(row + k) * 4).unwrap_or_default().as_chunks::<4>().0 {
+                for (a, v) in acc.iter_mut().zip(p) {
+                    *a += u32::from(*v);
+                }
+            }
+        }
+        for (d, a) in px.iter_mut().zip(acc) {
+            *d = ((a + n / 2) / n).min(255) as u8;
+        }
+    }
+    out
+}
+
 /// A rendered image (premultiplied RGBA8, row-major).
 pub struct Rendered {
     pub width: u32,
@@ -476,6 +519,16 @@ impl Renderer {
     /// screen colours (4 bytes a pixel, see [`Self::render_region_inks`]).
     fn render_as(&mut self, doc: &Document, width: u32, height: u32, view: Affine, opts: &RenderOptions, inks: bool) -> Rendered {
         let start = now();
+        if opts.supersample && opts.anti_alias == AntiAlias::Art && opts.mask_view.is_none() {
+            let (w, h) = (width.clamp(1, u16::MAX as u32), height.clamp(1, u16::MAX as u32));
+            if let Some(k) = supersample_factor(w, h) {
+                let hard = RenderOptions { anti_alias: AntiAlias::None, supersample: false, ..opts.clone() };
+                let big = self.render_as(doc, w * k, h * k, Affine::scale(f64::from(k)) * view, &hard, inks);
+                let pixels = downsample(&big.pixels, big.width as usize, big.height as usize, k as usize);
+                self.stats.micros = now().saturating_sub(start);
+                return Rendered { width: w, height: h, pixels };
+            }
+        }
         let prepared = proof::prepare(doc, opts);
         let doc: &Document = &prepared;
         let w = width.clamp(1, u16::MAX as u32) as u16;

crates/render/src/tests.rs

@@ -385,3 +385,41 @@ fn images_take_their_nearest_pixel_without_smoothing() {
     assert!(greys(true) >= 4, "smooth: a ramp from black to white");
     assert_eq!(greys(false), 0, "nearest: black, then white");
 }
+
+/// Art Optimized exports are supersampled (#983): two red shapes meeting along a diagonal leave no
+/// seam of the white background between them, where shape-by-shape smoothing shows one; the outer
+/// edges stay smooth.
+#[test]
+fn supersampled_art_leaves_no_seam_between_shapes_that_meet() {
+    let red = || Paint::solid(Color::rgb(1.0, 0.0, 0.0));
+    let mut d = Document::new(100.0, 100.0);
+    let layer = d.layers[0].id;
+    // Two triangles sharing the diagonal of the square (10, 10)–(90, 90).
+    for pts in [[(10.0, 10.0), (90.0, 10.0), (90.0, 90.0)], [(10.0, 10.0), (90.0, 90.0), (10.0, 90.0)]] {
+        let mut b = vectorcraft_geom::BezPath::new();
+        b.move_to(pts[0]);
+        b.line_to(pts[1]);
+        b.line_to(pts[2]);
+        b.close_path();
+        let id = d.alloc_id();
+        d.insert(Some(layer), 0, Node::path(id, vectorcraft_geom::PathData::from_bezpath(&b), Appearance::basic(red(), Paint::None, 0.0))).unwrap();
+    }
+    let draw = |supersample: bool| {
+        let opts = RenderOptions { background: Some([255, 255, 255, 255]), precise: true, supersample, ..Default::default() };
+        Renderer::new().render(&d, 100, 100, Affine::IDENTITY, &opts)
+    };
+    // The palest pixel on the shared diagonal, away from the corners.
+    let palest = |r: &Rendered| (20..80).map(|i| r.pixel(i, i)[1].max(r.pixel(i + 1, i)[1])).max().unwrap();
+    assert!(palest(&draw(false)) > 20, "shape-by-shape smoothing shows the seam");
+    assert_eq!(palest(&draw(true)), 0, "supersampled: no seam");
+    // The outer edge is still smoothed: a pixel half covered is between white and red.
+    let ss = draw(true);
+    let edge = ss.pixel(50, 9);
+    assert!(edge == [255, 255, 255, 255] || (edge[1] > 0 && edge[1] < 255) || ss.pixel(50, 10)[1] < 255, "{edge:?}");
+    // The factor fits the size and the renderer's limits.
+    assert_eq!(supersample_factor(100, 100), Some(4));
+    assert_eq!(supersample_factor(2000, 2000), Some(3));
+    assert_eq!(supersample_factor(3000, 3000), Some(2));
+    assert_eq!(supersample_factor(5000, 5000), None);
+    assert_eq!(supersample_factor(40_000, 10), None);
+}

crates/svg/src/import/spread.rs

@@ -2,7 +2,7 @@
 //! repeated (every other period mirrored, for reflect) as many times as the painted area needs,
 //! and the gradient stretched over those periods.
 
-use vectorcraft_color::{GradientGeom, GradientKind, GradientStop};
+use vectorcraft_color::{Gradient, GradientGeom, GradientKind, GradientStop};
 use vectorcraft_geom::{Point, Rect};
 
 /// Most periods a gradient is expanded to.
@@ -80,17 +80,9 @@ fn whole_period(stops: &[GradientStop]) -> Vec<GradientStop> {
 
 /// A period mirrored: the stops in reverse, each midpoint measured from the other side.
 fn mirror(period: &[GradientStop]) -> Vec<GradientStop> {
-    let rev: Vec<&GradientStop> = period.iter().rev().collect();
-    rev.iter()
-        .enumerate()
-        .map(|(i, s)| GradientStop {
-            offset: 1.0 - s.offset,
-            // The midpoint from this stop to the next one is the mirror of the one the next stop
-            // had towards this one.
-            midpoint: rev.get(i + 1).map_or(0.5, |next| 1.0 - next.midpoint),
-            ..(*s).clone()
-        })
-        .collect()
+    let mut g = Gradient { kind: GradientKind::Linear, stops: period.to_vec() };
+    g.reverse();
+    g.stops
 }
 
 #[cfg(test)]

crates/tools/src/cropimage.rs

@@ -232,9 +232,15 @@ impl Tool for CropImageTool {
         if key != "rect" {
             return;
         }
-        let n: Vec<f64> = value.as_array().map(|v| v.iter().filter_map(Value::as_f64).filter(|n| n.is_finite()).collect()).unwrap_or_default();
-        self.rect = match n.as_slice() {
-            [x, y, w, h] => Some((None, Rect::new(*x, *y, x + w, y + h))),
+        // Invalid components must discard the whole box, not silently shift the
+        // coordinates by dropping a non-numeric entry.
+        let numbers = value
+            .as_array()
+            .filter(|a| a.len() == 4)
+            .and_then(|a| a.iter().map(Value::as_f64).collect::<Option<Vec<_>>>())
+            .filter(|a| a.iter().all(|n| n.is_finite()));
+        self.rect = match numbers.as_deref() {
+            Some([x, y, w, h]) => Some((None, Rect::new(*x, *y, x + w, y + h))),
             _ => None,
         };
     }
@@ -336,6 +342,17 @@ mod tests {
         assert!(t.overlays(&cx).is_empty() && !t.claims_key(&cx, ToolKey::Enter));
     }
 
+    #[test]
+    fn crop_box_option_requires_exactly_four_finite_numeric_values() {
+        let mut tool = CropImageTool::default();
+        for invalid in [json!([10, "ignored", 20, 30, 40]), json!([10, 20, 30, null, 40]), json!([10, 20, 30, 40, 50]), json!("not a rectangle")] {
+            tool.set_option("rect", &invalid);
+            assert!(tool.options().get("rect").is_none(), "invalid box should reset crop: {invalid}");
+        }
+        tool.set_option("rect", &json!([10, 20, 30, 40]));
+        assert_eq!(tool.options()["rect"], json!([10.0, 20.0, 30.0, 40.0]));
+    }
+
     #[test]
     fn the_tool_is_made_by_its_id() {
         assert_eq!(crate::create(ID).id(), ID);

crates/ui-egui/src/control.rs

@@ -16,8 +16,8 @@
 //! - `ui.dialog.set {field, value}` / `ui.dialog.confirm` / `ui.dialog.cancel`
 //! - `ui.resize {width, height}`, `ui.focus`, `ui.screenshot {path?, data?}` (`data: true`: the PNG
 //!   comes back as `pngBase64` as well)
-//! - `ui.render {path?, scale?, data?}`: render the active artboard headlessly (PNG; without a path,
-//!   or with `data: true`, as `pngBase64`)
+//! - `ui.render {path?, scale?, artboard?, data?}`: render an artboard headlessly (`artboard`: its
+//!   0-based index, default the first; PNG; without a path, or with `data: true`, as `pngBase64`)
 //! - `app.open {path}` (any readable format) / `app.save {path?, svg?: {…SVG options}}` / `app.quit`
 //!   (`file.close`, `file.closeAll` and `app.quit` first open a `saveChanges` dialog for each
 //!   modified document: `ui.dialog.confirm` saves, set `discard: true` then confirm to discard)
@@ -321,7 +321,9 @@ pub fn handle(app: &mut VectorcraftApp, ctx: &egui::Context, req: &ControlReques
         "ui.render" => {
             let Some(st) = app.session.active() else { return err("no document") };
             let doc = st.doc.clone();
-            let Some(r) = doc.artboards.first().map(|a| a.rect) else { return err("no artboard") };
+            // The artboard asked for (0-based, as headless), else the first.
+            let index = p.get("artboard").and_then(Value::as_u64).map_or(Some(0), |i| usize::try_from(i).ok());
+            let Some(r) = index.and_then(|i| doc.artboards.get(i)).map(|a| a.rect) else { return err("no such artboard") };
             let scale = p.get("scale").and_then(Value::as_f64).unwrap_or(1.0);
             if let Err(e) = vectorcraft_render::raster_size(r, scale) {
                 return err(e);
@@ -390,3 +392,42 @@ pub fn save_screenshot(app: &mut VectorcraftApp, image: &egui::ColorImage, path:
         None => json!({"ok": false, "error": "no writer configured"}),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use serde_json::{Value, json};
+    use vectorcraft_engine::Session;
+
+    use super::ControlRequest;
+    use crate::{Services, VectorcraftApp};
+
+    /// #1004: `ui.render` (the MCP `screenshot` of a connected app) renders the artboard asked
+    /// for, at the scale asked for; the first without one.
+    #[test]
+    fn render_takes_the_artboard_asked_for() {
+        let (tx, rx) = std::sync::mpsc::channel();
+        let mut app = VectorcraftApp::new(Session::new(), Services::default()).with_control(rx);
+        let mut request = |method: &str, params: Value| {
+            let (req, reply) = ControlRequest::new(method, params);
+            tx.send(req).unwrap();
+            app.drain_control(&egui::Context::default());
+            reply.try_recv().unwrap()
+        };
+        let new = json!({"width": 64, "height": 64, "units": "Points", "artboards": 2});
+        request("engine.execute", json!({"command": "file.new", "params": new}));
+        let board = json!({"index": 1, "x": 100, "y": 0, "width": 96, "height": 48});
+        let r = request("engine.execute", json!({"command": "artboard.setProps", "params": board}));
+        assert_eq!(r["ok"], true, "{r}");
+        for (params, size) in [
+            (json!({}), [64, 64]),
+            (json!({"artboard": 0}), [64, 64]),
+            (json!({"artboard": 1}), [96, 48]),
+            (json!({"artboard": 1, "scale": 0.5}), [48, 24]),
+        ] {
+            let r = request("ui.render", params.clone());
+            let got = [&r["result"]["width"], &r["result"]["height"]].map(Value::as_u64);
+            assert_eq!(got, size.map(Some), "{params}: {r}");
+        }
+        assert!(request("ui.render", json!({"artboard": 2}))["error"].is_string());
+    }
+}

crates/ui-egui/src/dialogs/form.rs

@@ -248,7 +248,7 @@ pub(super) fn param_fields(
             match v {
                 Value::Number(n) => {
                     if let Some(x) = crate::widgets::plain_field(ui, ("fx-num", &k), n.as_f64().unwrap_or(0.0), "", 3, 140.0) {
-                        d.fields.insert(k, json!(x));
+                        d.fields.insert(k, typed_number(x));
                         changed = true;
                     }
                 }
@@ -291,6 +291,13 @@ pub(super) fn param_fields(
     changed
 }
 
+/// A number typed in a command's dialog as JSON: a whole number as an integer, as counts are read
+/// (`as_u64`: Object Mosaic's columns and rows, #1000), which `12.0` isn't; a fraction stays one.
+/// Commands that take any number read either.
+fn typed_number(x: f64) -> Value {
+    if x.fract() == 0.0 && x.abs() < 1e15 { json!(x as i64) } else { json!(x) }
+}
+
 /// Editor for a plug-in's parameters from its schema (plug-in filter and effect dialogs): numbers
 /// within their range, whole numbers, checkboxes and dropdowns, in declaration order. Returns
 /// true when a value changed. The labels (from the parameter keys) and choices are the plug-in's
@@ -552,3 +559,19 @@ pub(super) fn caption(ui: &mut egui::Ui, text: &str) {
     let t = Tokens::get(ui.ctx());
     ui.label(egui::RichText::new(tl!(text)).size(11.0).color(t.text_dim));
 }
+
+#[cfg(test)]
+mod typed_number_tests {
+    use super::*;
+
+    #[test]
+    fn whole_numbers_are_integers_and_fractions_stay_fractions() {
+        // Whatever the field held before: a count typed after a fraction is a count again.
+        assert_eq!(typed_number(24.0).as_u64(), Some(24));
+        assert_eq!(typed_number(-4.0), json!(-4));
+        assert_eq!(typed_number(0.0), json!(0));
+        assert_eq!(typed_number(2.5), json!(2.5));
+        // Numbers past exact integers stay floats.
+        assert!(typed_number(1e20).is_f64());
+    }
+}

crates/ui-egui/src/dialogs/tests.rs

@@ -434,6 +434,38 @@ fn a_dialog_opens_with_its_first_field_focused_so_typing_and_enter_apply() {
     assert_eq!(node.appearance.effects.last().map(|e| e.params["scaleH"].clone()), Some(json!(50.0)));
 }
 
+/// #1000: a count typed in Object › Create Object Mosaic… reaches the command (a whole number typed
+/// in a command's dialog is an integer), so the mosaic has that many columns, not the 10 × 10 grid.
+#[test]
+fn object_mosaic_makes_the_grid_typed_in_its_dialog() {
+    let mut app = app();
+    app.run("shape.rectangle", json!({"x": 10, "y": 10, "width": 60, "height": 40})).unwrap();
+    app.run("object.rasterize", json!({"ppi": 72})).unwrap();
+    let ctx = egui::Context::default();
+    theme::install_fonts(&ctx);
+    theme::apply(&ctx, Default::default());
+    let frame = |app: &mut VectorcraftApp, events: Vec<egui::Event>| {
+        let mut out = ctx.run_ui(egui::RawInput { events, ..Default::default() }, |ui| show(app, ui.ctx()));
+        out.textures_delta.clear();
+    };
+    let entry = crate::menus::menu_entries(&app).into_iter().find(|e| e.label == "Create Object Mosaic…").expect("menu item");
+    let (cmd, params) = crate::menus::click_target(&entry.label, entry.command.as_deref().unwrap(), &entry.params);
+    crate::menus::invoke(&mut app, &cmd, params);
+    // Its first field, Columns, is focused: type 3 over it and press Enter.
+    frame(&mut app, vec![]);
+    frame(&mut app, vec![egui::Event::Text("3".into())]);
+    let enter = egui::Event::Key { key: egui::Key::Enter, physical_key: None, pressed: true, repeat: false, modifiers: Default::default() };
+    frame(&mut app, vec![enter]);
+    assert!(app.ui.dialog.is_none());
+    let mut tiles = None;
+    app.session.doc().unwrap().doc.walk(|n| {
+        if n.name.as_deref() == Some("Object Mosaic") {
+            tiles = n.children().map(|c| c.len());
+        }
+    });
+    assert_eq!(tiles, Some(3 * 10));
+}
+
 /// #793: Artboard Options lists its fields as Name, Width, Height, not by key.
 #[test]
 fn artboard_options_lists_name_then_width_and_height() {

crates/ui-egui/src/i18n/de.tsv

@@ -3656,6 +3656,7 @@ theme	Appearance	Erscheinungsbild
 @msg	the image's pixels don't match its size	die Pixel des Bilds passen nicht zu seiner Größe
 @msg	the layer has no objects to clip by	die Ebene hat keine Objekte, an denen beschnitten werden könnte
 @msg	the layer or group is locked	die Ebene oder Gruppe ist gesperrt
+@msg	the target layer is locked or hidden	die Zielebene ist gesperrt oder ausgeblendet
 @msg	the layer to flatten into is hidden	die Ebene, auf die reduziert werden soll, ist ausgeblendet
 @msg	the object already has an opacity mask	das Objekt hat bereits eine Deckkraftmaske
 @msg	the object has no geometry	das Objekt hat keine Geometrie

crates/ui-egui/src/i18n/es.tsv

@@ -3759,6 +3759,7 @@ axis	Both	Ambos
 @msg	the image's pixels don't match its size	los píxeles de la imagen no coinciden con su tamaño
 @msg	the layer has no objects to clip by	la capa no tiene objetos con los que recortar
 @msg	the layer or group is locked	la capa o el grupo está bloqueado
+@msg	the target layer is locked or hidden	la capa de destino está bloqueada u oculta
 @msg	the layer to flatten into is hidden	la capa en la que acoplar está oculta
 @msg	the object already has an opacity mask	el objeto ya tiene una máscara de opacidad
 @msg	the object has no geometry	el objeto no tiene geometría

crates/ui-egui/src/i18n/fr.tsv

@@ -3756,6 +3756,7 @@ axis	Both	Les deux
 @msg	the image's pixels don't match its size	les pixels de l’image ne correspondent pas à sa taille
 @msg	the layer has no objects to clip by	le calque n’a aucun objet servant à l’écrêtage
 @msg	the layer or group is locked	le calque ou le groupe est verrouillé
+@msg	the target layer is locked or hidden	le calque cible est verrouillé ou masqué
 @msg	the layer to flatten into is hidden	le calque de destination de l’aplatissement est masqué
 @msg	the object already has an opacity mask	l’objet a déjà un masque d’opacité
 @msg	the object has no geometry	l’objet n’a pas de géométrie

crates/ui-egui/src/i18n/it.tsv

@@ -3759,6 +3759,7 @@ axis	Both	Entrambi
 @msg	the image's pixels don't match its size	i pixel dell'immagine non corrispondono alle sue dimensioni
 @msg	the layer has no objects to clip by	il livello non ha oggetti con cui ritagliare
 @msg	the layer or group is locked	il livello o il gruppo è bloccato
+@msg	the target layer is locked or hidden	il livello di destinazione è bloccato o nascosto
 @msg	the layer to flatten into is hidden	il livello in cui appiattire è nascosto
 @msg	the object already has an opacity mask	l'oggetto ha già una maschera di opacità
 @msg	the object has no geometry	l'oggetto non ha geometria

crates/ui-egui/src/i18n/ja.tsv

@@ -3497,6 +3497,7 @@ theme	Appearance	外観
 @msg	no selection bounds	選択範囲に境界がありません
 @msg	the layer has no objects to clip by	レイヤーにクリッピングマスクとして使えるオブジェクトがありません
 @msg	the layer or group is locked	レイヤーまたはグループがロックされています
+@msg	the target layer is locked or hidden	ターゲットレイヤーがロックされているか非表示です
 @msg	the layer to flatten into is hidden	統合先のレイヤーが非表示になっています
 @msg	there are no objects to release	レイヤーに分配するオブジェクトがありません
 @msg	no library `{id}`	ライブラリ `{id}` が見つかりません

crates/ui-egui/src/i18n/ru.tsv

@@ -3755,6 +3755,7 @@ axis	Both	Оба
 @msg	the image's pixels don't match its size	пиксели изображения не соответствуют его размеру
 @msg	the layer has no objects to clip by	в слое нет объектов для обрезки
 @msg	the layer or group is locked	слой или группа заблокированы
+@msg	the target layer is locked or hidden	целевой слой заблокирован или скрыт
 @msg	the layer to flatten into is hidden	слой для объединения скрыт
 @msg	the object already has an opacity mask	у объекта уже есть непрозрачная маска
 @msg	the object has no geometry	у объекта нет геометрии

crates/ui-egui/src/i18n/uk.tsv

@@ -3742,6 +3742,7 @@ axis	Both	Обидві
 @msg	the image's pixels don't match its size	пікселі зображення не відповідають його розміру
 @msg	the layer has no objects to clip by	у шарі немає об’єктів для обрізки
 @msg	the layer or group is locked	шар чи група заблоковані
+@msg	the target layer is locked or hidden	цільовий шар заблокований або прихований
 @msg	the layer to flatten into is hidden	шар для об’єднання прихований
 @msg	the object already has an opacity mask	об’єкт вже має маску непрозорості.
 @msg	the object has no geometry	об’єкт не має геометрії

crates/ui-egui/src/lib.rs

@@ -579,6 +579,16 @@ impl VectorcraftApp {
             return r;
         }
         let mut params = params;
+        // Paste in place, in front, in back (#693) and Select › All on Active Artboard (#1006): onto
+        // or on the active artboard, the view's.
+        if matches!(id, "edit.pasteInPlace" | "edit.pasteInFront" | "edit.pasteInBack" | "select.allOnArtboard")
+            && params.get("artboard").is_none()
+            && self.view().is_some()
+            && let Some(n) = self.session.active().map(|d| d.doc.artboards.len())
+            && let Some(p) = params.as_object_mut()
+        {
+            p.insert("artboard".into(), serde_json::json!(panels::artboards::selected(self, n)));
+        }
         if id.starts_with("edit.paste") {
             if let Err(e) = self.adopt_system_clipboard() {
                 self.ui.status = e.clone();
@@ -592,14 +602,6 @@ impl VectorcraftApp {
             {
                 p.insert("center".into(), serde_json::json!([c.x, c.y]));
             }
-            // In place, in front, in back: onto the active artboard (#693).
-            if matches!(id, "edit.pasteInPlace" | "edit.pasteInFront" | "edit.pasteInBack")
-                && params.get("artboard").is_none()
-                && let Some(i) = self.view().map(|v| v.artboard)
-                && let Some(p) = params.as_object_mut()
-            {
-                p.insert("artboard".into(), serde_json::json!(i));
-            }
             if let Some(r) = dialogs::swatch_conflict::ask(self, id, &params) {
                 return r;
             }

crates/ui-egui/src/panels/artboards.rs

@@ -235,6 +235,26 @@ mod tests {
         crate::menus::invoke(&mut app, "view.goToArtboard", json!({"index": "previous"}));
         assert_eq!(selected(&app, 2), 0, "and the panel follows the navigator");
     }
+
+    /// #1006: Select › All on Active Artboard selects the art of the artboard made active here,
+    /// and an explicit artboard still wins.
+    #[test]
+    fn all_on_active_artboard_takes_the_active_artboard() {
+        let mut app = VectorcraftApp::new(Session::new(), Default::default());
+        app.session.execute("file.new", &json!({"width": 100, "height": 100, "units": "Points", "artboards": 2})).unwrap();
+        let mut rect = |x| app.session.execute("shape.rectangle", &json!({"x": x, "y": 10, "width": 20, "height": 20})).unwrap()["id"].clone();
+        let (a, b) = (rect(10), rect(130));
+        let picked = |app: &mut VectorcraftApp, params| {
+            crate::menus::invoke(app, "select.allOnArtboard", params);
+            let ids: Vec<u64> = app.session.active().unwrap().selection.objects.iter().map(|n| n.0).collect();
+            json!(ids)
+        };
+        select(&mut app, 1);
+        assert_eq!(picked(&mut app, json!({})), json!([b]));
+        select(&mut app, 0);
+        assert_eq!(picked(&mut app, json!({})), json!([a]));
+        assert_eq!(picked(&mut app, json!({"artboard": 1})), json!([b]));
+    }
     /// Double-clicking a row's number goes to its artboard and its name renames it; a row's
     /// Options button edits that artboard with the Artboard tool, and the tool's artboard is the
     /// active one.

crates/ui-egui/src/panels/tests_strokeux.rs

@@ -139,3 +139,37 @@ fn weight_presets_display_cleanly_in_their_native_unit() {
     // Units no stroke is measured in keep the pt ladder, in points.
     assert_eq!(stroke::weight_presets(Unit::Meters), stroke::weight_presets(Unit::Points));
 }
+
+/// #991: the spinner left of the Stroke Weight field steps ten with Shift on both arrows and a
+/// tenth with Ctrl/Cmd, as ↑/↓ do in the focused field, while a plain click steps one point.
+#[test]
+fn stroke_weight_stepper_uses_ten_point_shift_steps() {
+    use super::tests_appearance::frame_raw;
+
+    let ctx = egui::Context::default();
+    crate::theme::install_fonts(&ctx);
+    let mut app = app_with_rect();
+    run(&mut app, "stroke.set", json!({"weight": 14}));
+    let t = texts(&ctx, &mut app, stroke::show);
+    // The 16 px spinner sits just left of the field's text.
+    let r = text_rect(&t, "14 pt");
+    let x = r.left() - 14.0;
+    let click_step = |app: &mut VectorcraftApp, y: f32, modifiers: egui::Modifiers| {
+        let pos = egui::pos2(x, y);
+        let button = |pressed| egui::Event::PointerButton { pos, button: egui::PointerButton::Primary, pressed, modifiers };
+        for event in [egui::Event::PointerMoved(pos), button(true), button(false)] {
+            let events = vec![egui::Event::ModifiersChanged(modifiers), event];
+            frame_raw(&ctx, app, egui::RawInput { events, ..Default::default() }, stroke::show);
+        }
+    };
+
+    click_step(&mut app, r.center().y - 5.0, egui::Modifiers::SHIFT);
+    assert_eq!(app.session.shown_stroke().unwrap().width, 24.0);
+    click_step(&mut app, r.center().y + 5.0, egui::Modifiers::NONE);
+    assert_eq!(app.session.shown_stroke().unwrap().width, 23.0);
+    click_step(&mut app, r.center().y + 5.0, egui::Modifiers::SHIFT);
+    assert_eq!(app.session.shown_stroke().unwrap().width, 13.0);
+    // Ctrl/Cmd steps a tenth, as ↑/↓ and the wheel do in the field.
+    click_step(&mut app, r.center().y + 5.0, egui::Modifiers::COMMAND);
+    assert!((app.session.shown_stroke().unwrap().width - 12.9).abs() < 1e-6);
+}

crates/ui-egui/src/widgets.rs

@@ -1170,8 +1170,8 @@ fn spin_generic(
             && let Some(p) = sresp.interact_pointer_pos()
             && let Some(v) = value
         {
-            let nv = if up.contains(p) { v + step } else { v - step };
-            out = Some(SpinPick::Value(nv.max(min)));
+            let modifiers = ui.input(|i| i.modifiers);
+            out = Some(SpinPick::Value(spinner_step(v, step, min, up.contains(p), modifiers)));
         }
         let fw = if presets.is_empty() { width - 15.0 } else { width - 34.0 };
         if let Some(v) = field(ui, fw) {
@@ -1198,6 +1198,14 @@ fn spin_generic(
     out
 }
 
+/// Spinner buttons follow the same modifier sizes as ↑/↓ in a focused number field:
+/// Shift ×10, Ctrl/Cmd ÷10, otherwise the caller's normal step.
+fn spinner_step(value: f64, step: f64, min: f64, up: bool, modifiers: egui::Modifiers) -> f64 {
+    let multiplier = STEPS.iter().find(|(m, _)| modifiers.matches_logically(*m)).map_or(1.0, |(_, factor)| *factor);
+    let delta = step * multiplier;
+    (value + if up { delta } else { -delta }).max(min)
+}
+
 /// Drag phase of a live slider/handle: previews while dragging, commits on release.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum Live {
@@ -1826,3 +1834,21 @@ pub fn text_presets(ui: &mut Ui, id: impl std::hash::Hash + std::fmt::Debug, val
     });
     out
 }
+
+#[cfg(test)]
+mod spinner_modifier_tests {
+    use super::*;
+
+    #[test]
+    fn shift_steps_stroke_weight_by_ten_points() {
+        assert_eq!(spinner_step(14.0, 1.0, 0.0, true, egui::Modifiers::SHIFT), 24.0);
+        assert_eq!(spinner_step(14.0, 1.0, 0.0, false, egui::Modifiers::SHIFT), 4.0);
+    }
+
+    #[test]
+    fn unmodified_and_command_steps_keep_existing_behavior() {
+        assert_eq!(spinner_step(14.0, 1.0, 0.0, true, egui::Modifiers::NONE), 15.0);
+        assert_eq!(spinner_step(14.0, 1.0, 0.0, false, egui::Modifiers::COMMAND), 13.9);
+        assert_eq!(spinner_step(0.0, 1.0, 0.0, false, egui::Modifiers::SHIFT), 0.0);
+    }
+}

docs/control-protocol.md

@@ -56,7 +56,7 @@ the two can still win that race.
 | `ui.set` | `{brightness?, panel?, rulers?, outline?, grid?, smartGuides?, boundingBox?, controlBar?}` | |
 | `ui.dialog.set` / `.confirm` / `.cancel` | `{field, value}` | fill and submit the open dialog |
 | `ui.screenshot` | `{path?, data?}` | capture the window (PNG), written to `path`; `data: true` sends it back as `pngBase64` too. Needs a presented frame: with the screen locked or the window minimized/covered it fails after ~8 s with an explanatory error |
-| `ui.render` | `{path?, scale?, data?}` | render the artboard headlessly (PNG): written to `path`, else (or with `data: true` as well) sent back as `pngBase64` |
+| `ui.render` | `{path?, scale?, artboard?, data?}` | render an artboard headlessly (PNG; `artboard`: its 0-based index, default the first): written to `path`, else (or with `data: true` as well) sent back as `pngBase64` |
 | `ui.resize` / `ui.focus` | | |
 | `app.open` / `app.save` / `app.export` / `app.quit` | `{path}` / `{path?}` / `{path?, format?, artboard?, range?, scale?, …}` | `app.open` reads every format `document.open` reads (see `document.formats`) and returns its result (`{index, title, format, warnings, …}`; `warnings` say what didn't come in as it was, such as an EPS shown as its preview image and why its PostScript couldn't be read), or null when a dialog asks first or a library loads. `app.export` encodes through the engine's `document.export` (same options; the document keeps its path) and writes `path` through the host; without `path` it returns `{dataBase64, format, bytes}`, as headless mode does. `app.quit`, `file.close` and `file.closeAll` first open a `saveChanges` dialog for each modified document (they return `{"pending": "saveChanges"}`): `ui.dialog.confirm` saves, `ui.dialog.set {field: "discard", value: true}` then confirm discards, `ui.dialog.cancel` cancels the whole close or quit |
 | `app.export` with `useArtboards` | `{path, useArtboards: true, range? \| artboards?, …}` | Export As: PNG, JPEG and WebP write one file per chosen artboard (default all; SVG does so for a `range`), `<path stem>-<artboard>.<ext>`, and return `{path, files: [path…]}`; a PDF keeps them as pages of `path`. `useArtboards: false` covers the bounds of the visible art. The menu's Export As… is `file.exportAs`: the `exportAs` dialog (`format`, `useArtboards`, `all`, `range`), then a save dialog and the format's options: `pngOptions` / `jpgOptions` / `webpOptions`, `svgOptions`, or `savePdf` for a PDF with Use Artboards |

docs/gaps.md

@@ -86,8 +86,7 @@ from G14 and the budget run of G15: **~170–270 h** one agent, ~50–80 h wall
 
 ## G11 Correctness bugs in core tools
 
-- **Missing:** Shape Builder misses planar regions and targets whole shapes (#937, #893); Asset Export
-  anti-aliasing ghost borders (#983); Transform effect dialog's invisible checkboxes and missing options (#885);
+- **Missing:** Shape Builder misses planar regions and targets whole shapes (#937, #893); Transform effect dialog's invisible checkboxes and missing options (#885);
   PDF text boxes moving on open (#722); SVG units reverting to points (#864); bezier drag preview freezing (#834).
 - **Impact:** wrong output in everyday work.
 - **Estimate:** 8–15 h.