diff --git a/crates/doc/src/selection.rs b/crates/doc/src/selection.rs
index 187c793b..50d79b9c 100644
--- a/crates/doc/src/selection.rs
+++ b/crates/doc/src/selection.rs
@@ -1,6 +1,6 @@
 //! Selection state (objects and, for direct selection, anchors and segments; ruler guides).
 
-use std::collections::{BTreeMap, BTreeSet};
+use std::collections::{BTreeMap, BTreeSet, HashSet};
 
 use serde::{Deserialize, Serialize};
 
@@ -165,9 +165,17 @@ impl Selection {
     /// around them (and so the key object when it is one): hidden or locked art can't stay
     /// selected.
     pub fn deselect_uneditable(&mut self, doc: &Document) {
-        let out: Vec<NodeId> = self.objects.iter().copied().filter(|o| !doc.is_editable(*o)).collect();
-        for o in out {
-            self.remove(o);
+        let uneditable: HashSet<NodeId> = self.objects.iter().copied().filter(|o| !doc.is_editable(*o)).collect();
+        if uneditable.is_empty() {
+            return;
+        }
+        self.target = None;
+        self.slices.clear();
+        self.objects.retain(|o| !uneditable.contains(o));
+        self.anchors.retain(|id, _| !uneditable.contains(id));
+        self.segments.retain(|id, _| !uneditable.contains(id));
+        if self.key.is_some_and(|k| uneditable.contains(&k)) {
+            self.key = None;
         }
     }
     /// Target `id` (see [`Selection::target`]): a layer gets its visible, unlocked art selected
@@ -208,134 +216,4 @@ impl Selection {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn basic_ops() {
-        let mut s = Selection::default();
-        s.add(NodeId(1));
-        s.add(NodeId(1));
-        s.toggle(NodeId(2));
-        assert_eq!(s.objects, vec![NodeId(1), NodeId(2)]);
-        s.toggle(NodeId(1));
-        assert_eq!(s.objects, vec![NodeId(2)]);
-        s.clear();
-        assert!(s.is_empty());
-    }
-
-    #[test]
-    fn guides_are_selected_on_their_own() {
-        let mut s = Selection::default();
-        s.add(NodeId(1));
-        s.set_guides([2, 0, 2]);
-        assert_eq!((s.objects.clone(), s.guides.clone()), (vec![], vec![2, 0]));
-        assert!(s.has_objects_or_guides() && s.is_empty());
-        // Shift-adding an object keeps them; a new selection doesn't.
-        s.add(NodeId(1));
-        assert_eq!(s.guides, vec![2, 0]);
-        s.set([NodeId(1)]);
-        assert!(s.guides.is_empty());
-        // Toggled, a guide joins (or leaves) the selected objects.
-        s.toggle_guide(0);
-        assert_eq!((s.objects.clone(), s.guides.clone()), (vec![NodeId(1)], vec![0]));
-        s.toggle_guide(0);
-        assert_eq!((s.objects.clone(), s.guides.clone()), (vec![NodeId(1)], vec![]));
-        // Pruning drops guides the document no longer has.
-        let mut d = Document::new(100.0, 100.0);
-        d.guides.push(crate::Guide::new(true, 10.0));
-        s.set_guides([0, 1]);
-        s.prune(&d);
-        assert_eq!(s.guides, vec![0]);
-    }
-
-    #[test]
-    fn guides_show_and_lock_with_their_layer() {
-        let mut d = Document::new(100.0, 100.0);
-        let layer = d.layers[0].id;
-        let g = crate::Guide { layer: Some(layer), ..crate::Guide::new(true, 10.0) };
-        assert!(d.guide_shown(&g) && d.guide_editable(&g));
-        d.node_mut(layer).unwrap().locked = true;
-        assert!(d.guide_shown(&g) && !d.guide_editable(&g), "locked: shown, not editable");
-        d.node_mut(layer).unwrap().visible = false;
-        assert!(!d.guide_shown(&g) && !d.guide_editable(&g), "hidden");
-        // On no layer, or a layer that's gone: always there.
-        assert!(d.guide_shown(&crate::Guide::new(false, 5.0)));
-        let gone = crate::Guide { layer: Some(NodeId(9999)), ..crate::Guide::new(true, 1.0) };
-        assert!(d.guide_shown(&gone) && d.guide_editable(&gone));
-        d.guides.push(g);
-        assert_eq!(d.guides_on(layer).count(), 1);
-        // Guides on no layer, or a gone one, are adopted by the top visible, unlocked layer.
-        d.node_mut(layer).unwrap().visible = true;
-        d.node_mut(layer).unwrap().locked = false;
-        d.guides.push(crate::Guide::new(false, 5.0));
-        d.guides.push(gone);
-        assert_eq!(d.adopt_guides(), 2);
-        assert!(d.guides.iter().all(|g| g.layer == Some(layer)));
-        assert_eq!(d.adopt_guides(), 0, "once");
-        // A guide saved before guides had layers reads as one on no layer.
-        let old: crate::Guide = serde_json::from_str(r#"{"vertical": true, "pos": 5.0}"#).unwrap();
-        assert_eq!(old.layer, None);
-        assert!(!serde_json::to_string(&crate::Guide::new(true, 5.0)).unwrap().contains("layer"), "nothing new written");
-    }
-
-    #[test]
-    fn selection_changes_clear_the_target() {
-        let mut s = Selection::default();
-        s.set([NodeId(2), NodeId(3)]);
-        s.target = Some(NodeId(1));
-        assert_eq!(s.subjects(), &[NodeId(1)]);
-        s.add(NodeId(4));
-        assert_eq!(s.target, None);
-        assert_eq!(s.subjects(), &[NodeId(2), NodeId(3), NodeId(4)]);
-        s.target = Some(NodeId(1));
-        s.remove(NodeId(2));
-        assert_eq!(s.target, None);
-        s.target = Some(NodeId(1));
-        s.set([NodeId(3)]);
-        assert_eq!(s.target, None);
-    }
-
-    #[test]
-    fn a_key_object_needs_two_or_more_selected_objects() {
-        let mut s = Selection::default();
-        s.set([NodeId(1), NodeId(2)]);
-        s.key = Some(NodeId(2));
-        s.remove(NodeId(1));
-        assert_eq!(s.key, Some(NodeId(2)), "another object left: remove keeps the key");
-        s.remove(NodeId(2));
-        assert_eq!(s.key, None, "the key object itself left");
-        // Pruning drops objects the document no longer has and clears the key once no other
-        // selected object lies outside it.
-        let mut d = Document::new(100.0, 100.0);
-        let layer = d.layers[0].id;
-        let mut ids = vec![];
-        for _ in 0..4 {
-            let id = d.alloc_id();
-            ids.push(d.insert(Some(layer), usize::MAX, crate::Node::group(id, vec![])).unwrap());
-        }
-        s.set(ids.iter().copied());
-        s.key = Some(ids[3]);
-        d.remove(ids[0]).unwrap();
-        s.prune(&d);
-        assert_eq!(s.key, Some(ids[3]), "three objects left: the key stays");
-        s.toggle(ids[1]);
-        s.prune(&d);
-        assert_eq!(s.key, Some(ids[3]), "two objects left: the key stays");
-        s.toggle(ids[2]);
-        s.prune(&d);
-        assert_eq!((s.objects.clone(), s.key), (vec![ids[3]], None), "one object left");
-        // A group key selected with only its own member is cleared too; another selected object
-        // outside the group keeps it.
-        let member = d.alloc_id();
-        d.insert(Some(ids[3]), usize::MAX, crate::Node::group(member, vec![])).unwrap();
-        s.set([member, ids[3]]);
-        s.key = Some(ids[3]);
-        s.prune(&d);
-        assert_eq!(s.key, None, "a group and its own member");
-        s.set([member, ids[3], ids[2]]);
-        s.key = Some(ids[3]);
-        s.prune(&d);
-        assert_eq!(s.key, Some(ids[3]), "another object outside the group");
-    }
-}
+mod tests;
diff --git a/crates/doc/src/selection/tests.rs b/crates/doc/src/selection/tests.rs
new file mode 100644
index 00000000..5665f114
--- /dev/null
+++ b/crates/doc/src/selection/tests.rs
@@ -0,0 +1,219 @@
+use std::sync::Arc;
+
+use super::*;
+use crate::Node;
+
+#[test]
+fn basic_ops() {
+    let mut s = Selection::default();
+    s.add(NodeId(1));
+    s.add(NodeId(1));
+    s.toggle(NodeId(2));
+    assert_eq!(s.objects, vec![NodeId(1), NodeId(2)]);
+    s.toggle(NodeId(1));
+    assert_eq!(s.objects, vec![NodeId(2)]);
+    s.clear();
+    assert!(s.is_empty());
+}
+
+#[test]
+fn guides_are_selected_on_their_own() {
+    let mut s = Selection::default();
+    s.add(NodeId(1));
+    s.set_guides([2, 0, 2]);
+    assert_eq!((s.objects.clone(), s.guides.clone()), (vec![], vec![2, 0]));
+    assert!(s.has_objects_or_guides() && s.is_empty());
+    // Shift-adding an object keeps them; a new selection doesn't.
+    s.add(NodeId(1));
+    assert_eq!(s.guides, vec![2, 0]);
+    s.set([NodeId(1)]);
+    assert!(s.guides.is_empty());
+    // Toggled, a guide joins (or leaves) the selected objects.
+    s.toggle_guide(0);
+    assert_eq!((s.objects.clone(), s.guides.clone()), (vec![NodeId(1)], vec![0]));
+    s.toggle_guide(0);
+    assert_eq!((s.objects.clone(), s.guides.clone()), (vec![NodeId(1)], vec![]));
+    // Pruning drops guides the document no longer has.
+    let mut d = Document::new(100.0, 100.0);
+    d.guides.push(crate::Guide::new(true, 10.0));
+    s.set_guides([0, 1]);
+    s.prune(&d);
+    assert_eq!(s.guides, vec![0]);
+}
+
+#[test]
+fn guides_show_and_lock_with_their_layer() {
+    let mut d = Document::new(100.0, 100.0);
+    let layer = d.layers[0].id;
+    let g = crate::Guide { layer: Some(layer), ..crate::Guide::new(true, 10.0) };
+    assert!(d.guide_shown(&g) && d.guide_editable(&g));
+    d.node_mut(layer).unwrap().locked = true;
+    assert!(d.guide_shown(&g) && !d.guide_editable(&g), "locked: shown, not editable");
+    d.node_mut(layer).unwrap().visible = false;
+    assert!(!d.guide_shown(&g) && !d.guide_editable(&g), "hidden");
+    // On no layer, or a layer that's gone: always there.
+    assert!(d.guide_shown(&crate::Guide::new(false, 5.0)));
+    let gone = crate::Guide { layer: Some(NodeId(9999)), ..crate::Guide::new(true, 1.0) };
+    assert!(d.guide_shown(&gone) && d.guide_editable(&gone));
+    d.guides.push(g);
+    assert_eq!(d.guides_on(layer).count(), 1);
+    // Guides on no layer, or a gone one, are adopted by the top visible, unlocked layer.
+    d.node_mut(layer).unwrap().visible = true;
+    d.node_mut(layer).unwrap().locked = false;
+    d.guides.push(crate::Guide::new(false, 5.0));
+    d.guides.push(gone);
+    assert_eq!(d.adopt_guides(), 2);
+    assert!(d.guides.iter().all(|g| g.layer == Some(layer)));
+    assert_eq!(d.adopt_guides(), 0, "once");
+    // A guide saved before guides had layers reads as one on no layer.
+    let old: crate::Guide = serde_json::from_str(r#"{"vertical": true, "pos": 5.0}"#).unwrap();
+    assert_eq!(old.layer, None);
+    assert!(!serde_json::to_string(&crate::Guide::new(true, 5.0)).unwrap().contains("layer"), "nothing new written");
+}
+
+#[test]
+fn selection_changes_clear_the_target() {
+    let mut s = Selection::default();
+    s.set([NodeId(2), NodeId(3)]);
+    s.target = Some(NodeId(1));
+    assert_eq!(s.subjects(), &[NodeId(1)]);
+    s.add(NodeId(4));
+    assert_eq!(s.target, None);
+    assert_eq!(s.subjects(), &[NodeId(2), NodeId(3), NodeId(4)]);
+    s.target = Some(NodeId(1));
+    s.remove(NodeId(2));
+    assert_eq!(s.target, None);
+    s.target = Some(NodeId(1));
+    s.set([NodeId(3)]);
+    assert_eq!(s.target, None);
+}
+
+#[test]
+fn a_key_object_needs_two_or_more_selected_objects() {
+    let mut s = Selection::default();
+    s.set([NodeId(1), NodeId(2)]);
+    s.key = Some(NodeId(2));
+    s.remove(NodeId(1));
+    assert_eq!(s.key, Some(NodeId(2)), "another object left: remove keeps the key");
+    s.remove(NodeId(2));
+    assert_eq!(s.key, None, "the key object itself left");
+    // Pruning drops objects the document no longer has and clears the key once no other
+    // selected object lies outside it.
+    let mut d = Document::new(100.0, 100.0);
+    let layer = d.layers[0].id;
+    let mut ids = vec![];
+    for _ in 0..4 {
+        let id = d.alloc_id();
+        ids.push(d.insert(Some(layer), usize::MAX, crate::Node::group(id, vec![])).unwrap());
+    }
+    s.set(ids.iter().copied());
+    s.key = Some(ids[3]);
+    d.remove(ids[0]).unwrap();
+    s.prune(&d);
+    assert_eq!(s.key, Some(ids[3]), "three objects left: the key stays");
+    s.toggle(ids[1]);
+    s.prune(&d);
+    assert_eq!(s.key, Some(ids[3]), "two objects left: the key stays");
+    s.toggle(ids[2]);
+    s.prune(&d);
+    assert_eq!((s.objects.clone(), s.key), (vec![ids[3]], None), "one object left");
+    // A group key selected with only its own member is cleared too; another selected object
+    // outside the group keeps it.
+    let member = d.alloc_id();
+    d.insert(Some(ids[3]), usize::MAX, crate::Node::group(member, vec![])).unwrap();
+    s.set([member, ids[3]]);
+    s.key = Some(ids[3]);
+    s.prune(&d);
+    assert_eq!(s.key, None, "a group and its own member");
+    s.set([member, ids[3], ids[2]]);
+    s.key = Some(ids[3]);
+    s.prune(&d);
+    assert_eq!(s.key, Some(ids[3]), "another object outside the group");
+}
+
+fn below(r: &mut u64, n: u64) -> u64 {
+    *r ^= *r << 13;
+    *r ^= *r >> 7;
+    *r ^= *r << 17;
+    *r % n.max(1)
+}
+
+fn random_group(d: &mut Document, r: &mut u64, depth: u64, ids: &mut Vec<NodeId>) -> Arc<Node> {
+    let id = d.alloc_id();
+    ids.push(id);
+    let count = if depth == 0 { 0 } else { 1 + below(r, 4) };
+    let children = (0..count)
+        .map(|_| {
+            let depth = below(r, depth);
+            random_group(d, r, depth, ids)
+        })
+        .collect();
+    let mut group = Node::group(id, children);
+    group.locked = below(r, 6) == 0;
+    group.visible = below(r, 6) != 0;
+    Arc::new(group)
+}
+
+fn random_document(r: &mut u64) -> (Document, Vec<NodeId>) {
+    let mut d = Document::new(100.0, 100.0);
+    let mut ids = vec![];
+    for _ in 0..3 {
+        let mut layer = Node::layer(d.alloc_id(), "L", crate::LayerColor::Preset(0));
+        let children = (0..1 + below(r, 4)).map(|_| random_group(&mut d, r, 3, &mut ids)).collect();
+        if let Some(c) = layer.children_mut() {
+            *c = children;
+        }
+        layer.locked = below(r, 6) == 0;
+        layer.visible = below(r, 6) != 0;
+        d.layers.push(Arc::new(layer));
+    }
+    (d, ids)
+}
+
+fn random_selection(r: &mut u64, ids: &[NodeId]) -> Selection {
+    let mut s = Selection::default();
+    let missing = (below(r, 2) == 0).then_some(NodeId(u64::MAX));
+    s.set(ids.iter().copied().filter(|_| below(r, 2) == 0).chain(missing));
+    let k = below(r, s.objects.len() as u64) as usize;
+    s.objects.rotate_left(k);
+    for &o in &s.objects {
+        match below(r, 3) {
+            0 => {
+                s.anchors.insert(o, BTreeSet::from([(0, 0)]));
+            }
+            1 => {
+                s.anchors.insert(o, BTreeSet::from([(0, 1)]));
+                s.segments.insert(o, BTreeSet::from([(0, 0)]));
+            }
+            _ => {}
+        }
+    }
+    s.key = s.objects.get(below(r, s.objects.len() as u64) as usize).copied();
+    s.target = ids.get(below(r, ids.len() as u64) as usize).copied().filter(|_| below(r, 2) == 0);
+    s.slices = ids.iter().copied().take(below(r, 3) as usize).collect();
+    s.guides = vec![1, 0];
+    s
+}
+
+#[test]
+fn deselect_uneditable_matches_removing_one_at_a_time() {
+    let (mut unchanged, mut partial) = (0, 0);
+    for seed in 1..400u64 {
+        let mut r = seed.wrapping_mul(0x9e37_79b9_7f4a_7c15) | 1;
+        let (d, mut ids) = random_document(&mut r);
+        if seed % 4 == 0 {
+            ids.retain(|id| d.is_editable(*id));
+        }
+        let s = random_selection(&mut r, &ids);
+        let mut expected = s.clone();
+        for o in s.objects.iter().copied().filter(|o| !d.is_editable(*o)) {
+            expected.remove(o);
+        }
+        let mut actual = s.clone();
+        actual.deselect_uneditable(&d);
+        assert_eq!(actual, expected, "seed {seed}");
+        unchanged += usize::from(actual == s);
+        partial += usize::from(!actual.objects.is_empty() && actual.objects.len() < s.objects.len());
+    }
+    assert!(unchanged > 10 && partial > 100, "{unchanged} {partial}");
+}