fix(doc): consecutive right pages after a section restart get separate spreads

ROADMAP.md

@@ -347,6 +347,7 @@ list) · [roadmap.md](docs/roadmap.md) (milestones, plan) · [parity-checklist.m
 
 Newest first.
 
+- **2026-10-15** · In a facing-pages document, two odd-numbered pages in a row after a section restart (page 2 starting at 1) each get their own spread and stay right pages, instead of sharing a spread with an odd page on the left. No readiness percentage change.
 - **2026-10-14** · The Type tool draws a new text frame over a locked empty frame, as InDesign does, instead of turning the locked frame into a text frame. No readiness percentage change.
 - **2026-10-14** · 100% black shows as pure black on screen by default, as InDesign's Appearance of Black does out of the box (Display All Blacks as Rich Black); Preferences › Appearance of Black › Display All Blacks Accurately still shows it as the dark grey it prints, and a saved choice is kept. No readiness percentage change.
 - **2026-10-14** · Pathfinder keeps the frontmost object, as InDesign does: a photo placed over shapes and intersected with them shows through the shapes (it was dropped, and the shapes kept their black fill); Add, Exclude Overlap and Minus Back take the front object's fill too, Subtract still keeps the back one. No readiness percentage change.

crates/doc/src/build.rs

@@ -346,7 +346,10 @@ impl Document {
                 let odd = parity.get(i).copied().unwrap_or(i % 2 == 0);
                 p.side = if odd != rtl { PageSide::Right } else { PageSide::Left };
                 let starts = if rtl { PageSide::Right } else { PageSide::Left };
-                if p.side == starts && !cur.is_empty() {
+                // A right page closes its spread, so two right pages in a row (a section restart
+                // at an even position) never share one.
+                let after_ending = cur.last().is_some_and(|(q, _)| q.side != starts);
+                if (p.side == starts || after_ending) && !cur.is_empty() {
                     let id = SpreadId(self.alloc());
                     flush(&mut cur, &mut spreads, id);
                 }

crates/doc/src/tests.rs

@@ -262,6 +262,29 @@ fn page_names_follow_sections() {
     assert_eq!(d.page_name(5), "4");
 }
 
+/// A section restarting at 1 on page 2 leaves two odd (right) pages in a row; each gets its own
+/// spread instead of sharing one with the odd page on the left.
+#[test]
+fn consecutive_right_pages_get_separate_spreads() {
+    let mut d = Document::new(&NewDocument { pages: 4, ..Default::default() });
+    d.sections.push(Section {
+        start: 1,
+        start_number: Some(1),
+        style: NumberStyle::Arabic,
+        prefix: String::new(),
+        marker: String::new(),
+        include_prefix: false,
+    });
+    d.repaginate();
+    let sides: Vec<Vec<PageSide>> = d.spreads.iter().map(|s| s.pages.iter().map(|p| p.side).collect()).collect();
+    assert_eq!(sides, vec![vec![PageSide::Right], vec![PageSide::Right], vec![PageSide::Left, PageSide::Right]]);
+    let flat: Vec<PageSide> = sides.into_iter().flatten().collect();
+    for (i, side) in flat.iter().enumerate() {
+        assert_eq!(*side == PageSide::Right, d.page_number(i) % 2 == 1, "page {i}");
+    }
+    d.check().unwrap();
+}
+
 #[test]
 fn document_serde_roundtrip() {
     let mut d = doc();