Merge PR #302

crates/compose/src/tests.rs

@@ -1622,6 +1622,27 @@ fn warichu_stacks_the_run_inside_the_line_and_closes_up() {
     assert!((l.end_x - (z.x + z.adv)).abs() < 1e-3, "the line-end caret follows the close-up");
 }
 
+#[test]
+fn warichu_line_spacing_from_a_document_stays_finite() {
+    for spacing in [1e308, -1e308, f64::INFINITY, f64::NAN] {
+        let mut d = Document::new(&designcraft_doc::build::NewDocument::default());
+        let lid = d.default_layer();
+        let (_, sid) = d.add_text_frame(SpreadRef::Doc(0), Rect::new(36.0, 36.0, 500.0, 200.0), lid, "ABCDEFGHZ", ParaFormat::default()).unwrap();
+        d.story_mut(sid).unwrap().format_chars(0..8, |f| {
+            f.over.warichu = Some(true);
+            f.over.warichu_lines = Some(16);
+            f.over.warichu_line_spacing = Some(spacing);
+        });
+        let cs = compose_story(&d, sid, &ComposeOptions::default());
+        let l = &cs.frames[0].lines[0];
+        assert!(
+            l.glyphs.iter().all(|g| g.x.is_finite() && g.y.is_finite() && g.y.abs() < 1e4),
+            "{spacing}: {:?}",
+            l.glyphs.iter().map(|g| g.y).collect::<Vec<_>>()
+        );
+    }
+}
+
 #[test]
 fn warichu_break_minimum_keeps_a_short_run_on_one_line() {
     let mut d = Document::new(&designcraft_doc::build::NewDocument::default());

crates/compose/src/warichu.rs

@@ -84,7 +84,8 @@ fn line_count(len: usize, want: usize, before: usize, after: usize) -> usize {
     let before = before.max(1);
     let after = after.max(1);
     while n >= 2 {
-        if before + after + n - 2 <= len {
+        // The minimums come from documents and commands: on 32-bit targets their sum can overflow.
+        if before.saturating_add(after).saturating_add(n - 2) <= len {
             return n;
         }
         n -= 1;
@@ -220,7 +221,9 @@ fn layout(styles: &[RunStyle], line: &mut [PlacedGlyph], members: &[usize]) -> f
     let small = st.size * scale;
     // 0 is the default (one small em). Any other value, including a negative one, is added to
     // that em and then clamped so the rows cannot swap order.
-    let gap = if st.warichu_line_spacing == 0.0 { small } else { (small + st.warichu_line_spacing).max(0.0) };
+    // Bounded, so a hostile value can't move a row to an infinite or huge coordinate.
+    let spacing = if st.warichu_line_spacing.is_finite() { st.warichu_line_spacing.clamp(-16.0 * st.size, 16.0 * st.size) } else { 0.0 };
+    let gap = if spacing == 0.0 { small } else { (small + spacing).max(0.0) };
     let mut off = 0_usize;
     for (li, &c) in counts.iter().enumerate() {
         let w = widths[li];
@@ -264,3 +267,15 @@ fn layout(styles: &[RunStyle], line: &mut [PlacedGlyph], members: &[usize]) -> f
     }
     delta
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn huge_break_minimums_keep_one_line() {
+        assert_eq!(line_count(10, 2, usize::MAX, 1), 1);
+        assert_eq!(line_count(10, 3, 1, usize::MAX), 1);
+        assert_eq!(line_count(10, 2, 3, 3), 2);
+    }
+}