fix(compose): text recomposes when the baseline grid, a wrap layer's visibility or section numbering changes (#718)

ROADMAP.md

@@ -129,6 +129,7 @@ list) · [roadmap.md](docs/roadmap.md) (milestones, plan) · [parity-checklist.m
 
 Newest first.
 
+- **2026-10-13** · Text recomposes when the document baseline grid changes, when a layer holding a text-wrap object is shown or hidden, or when a section's start number, numbering style, prefix or marker changes; the composition cache keyed only on the section count and item identities and kept the old layout. No readiness percentage change.
 - **2026-10-12** · macOS Dock Quit uses the same unsaved-document prompts as window and menu Quit. Repeated requests keep the current answers; Cancel retains every tab and unsaved recovery checkpoint, and completed Save/Don't Save answers exit through the ordinary event loop. No readiness percentage change.
 - **2026-10-12** · Orderly native exit writes the latest recovery state after finalizing current quit approvals; incomplete or stale plans keep their documents, and Undo to the saved state clears stale recovery. Unavailable or failed recovery is reported. Cancelable macOS Dock Quit remains open (#544). No readiness percentage change.
 - **2026-10-12** · Recovered documents keep a checkpoint until saved, closed or reverted, including a second crash before autosave. Restarted document IDs and explicit recovery folders preserve other snapshots; failed republishing retains the original. No readiness percentage change.

crates/compose/src/cache.rs

@@ -47,7 +47,18 @@ fn doc_signature(doc: &Document) -> u64 {
     }
     (Arc::as_ptr(&doc.styles) as usize).hash(&mut h);
     format!("{:?}", doc.text_variables).hash(&mut h);
+    sections_hash(doc).hash(&mut h);
+    h.finish()
+}
+
+/// Everything page names and section markers are made from.
+fn sections_hash(doc: &Document) -> u64 {
+    use std::hash::{Hash, Hasher};
+    let mut h = std::collections::hash_map::DefaultHasher::new();
     doc.sections.len().hash(&mut h);
+    for s in &doc.sections {
+        (s.start, s.start_number, s.style as u8, &s.prefix, &s.marker, s.include_prefix).hash(&mut h);
+    }
     h.finish()
 }
 
@@ -253,8 +264,17 @@ impl Cache {
 
 fn signature(doc: &Document, story: &Arc<Story>) -> (Vec<usize>, Vec<Arc<Item>>) {
     // The document's font scope: another document's fonts of the same name set it differently.
-    let mut sig =
-        vec![Arc::as_ptr(story) as usize, story.rev as usize, Arc::as_ptr(&doc.styles) as usize, doc.sections.len(), doc.font_scope as usize];
+    // Sections name the pages under the frames (page-number and section markers).
+    let g = &doc.settings.baseline_grid;
+    let mut sig = vec![
+        Arc::as_ptr(story) as usize,
+        story.rev as usize,
+        Arc::as_ptr(&doc.styles) as usize,
+        sections_hash(doc) as usize,
+        doc.font_scope as usize,
+        g.start.to_bits() as usize,
+        g.increment.to_bits() as usize,
+    ];
     let mut keep = Vec::new();
     let mut spreads = Vec::new();
     for f in &story.frames {
@@ -273,6 +293,8 @@ fn signature(doc: &Document, story: &Arc<Story>) -> (Vec<usize>, Vec<Arc<Item>>)
                 for it in &sp.items {
                     if it.wrap.mode != WrapMode::None {
                         sig.push(Arc::as_ptr(it) as usize);
+                        // Wrap objects on hidden layers don't wrap text.
+                        sig.push(usize::from(doc.layer(it.layer).is_some_and(|l| l.visible)));
                         keep.push(it.clone());
                     }
                 }

crates/compose/src/tests.rs

@@ -2929,3 +2929,47 @@ fn empty_paragraphs_get_no_bullet_or_number() {
         assert_eq!(list_labels(&cs, LABEL_CHARS), ["1.", "", "2.", ""], "list `{name}`");
     }
 }
+
+#[test]
+fn cache_recomposes_when_the_baseline_grid_changes() {
+    let para = ParaAttrs { grid_align: Some(GridAlign::AllLines), ..Default::default() };
+    let (mut d, sid, _) = doc_with(LOREM, Rect::new(0.0, 0.0, 200.0, 600.0), para);
+    let cache = Cache::new();
+    let a = cache.get(&d, sid, None);
+    d.settings.baseline_grid.increment = 30.0;
+    let b = cache.get(&d, sid, None);
+    assert!(!Arc::ptr_eq(&a, &b));
+    let (la, lb) = (&a.frames[0].lines[1], &b.frames[0].lines[1]);
+    assert!((la.baseline - lb.baseline).abs() > 1.0, "{} {}", la.baseline, lb.baseline);
+}
+
+#[test]
+fn cache_recomposes_when_a_wrap_layer_is_hidden() {
+    let (mut d, sid, _) = doc_with(&[LOREM; 2].join(" "), Rect::new(0.0, 0.0, 300.0, 800.0), ParaAttrs::default());
+    let lid = d.default_layer();
+    let id = ItemId(d.alloc());
+    let mut it =
+        designcraft_doc::Item::new(id, lid, designcraft_doc::Shape::Rectangle, designcraft_geom::shapes::rectangle(Rect::new(0.0, 0.0, 120.0, 60.0)));
+    it.wrap.mode = WrapMode::BoundingBox;
+    d.insert_item(SpreadRef::Doc(0), it, None).unwrap();
+    let cache = Cache::new();
+    let a = cache.get(&d, sid, None);
+    assert!(a.frames[0].lines[0].x0 >= 120.0 - 1e-6);
+    d.layer_mut(lid).unwrap().visible = false;
+    let b = cache.get(&d, sid, None);
+    assert!(!Arc::ptr_eq(&a, &b));
+    assert!(b.frames[0].lines[0].x0 < 1.0, "{}", b.frames[0].lines[0].x0);
+}
+
+#[test]
+fn cache_recomposes_page_numbers_when_a_section_is_renumbered() {
+    let text = story::PAGE_NUMBER.to_string();
+    let (mut d, sid, _) = doc_with(&text, Rect::new(0.0, 0.0, 300.0, 100.0), ParaAttrs::default());
+    let cache = Cache::new();
+    let a = cache.get(&d, sid, None);
+    assert_eq!(a.frames[0].lines[0].glyphs.len(), 1);
+    d.sections[0].start_number = Some(1000);
+    let b = cache.get(&d, sid, None);
+    assert!(!Arc::ptr_eq(&a, &b));
+    assert_eq!(b.frames[0].lines[0].glyphs.len(), 4);
+}