Compose: spaces at the end of a paragraph take no room on the line

The paragraph composer counted a trailing space (or several) before the
paragraph end or a forced line break in the line's width, so "2 VOOR " in a
frame exactly as wide as "2 VOOR" broke before "VOOR" and the frame went
overset. InDesign lets those spaces hang past the edge. They now add no
width; the line's visible range already left them out.

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

crates/compose/src/breaker.rs

@@ -303,8 +303,17 @@ fn items(glyphs: &[Glyph], hyph_after: &[bool], emergency_after: &[bool], sp: &S
     let n = glyphs.len();
     let mut hy_cache = Vec::new();
     let mut last_space = NONE;
+    // Spaces before the paragraph end or a forced break hang: they take no room on the line (as
+    // in InDesign, where "2 VOOR " fits a frame as wide as "2 VOOR").
+    let mut hangs = vec![false; n];
+    for i in (0..n).rev() {
+        hangs[i] = glyphs[i].is_space() && glyphs.get(i + 1).is_none_or(|nx| hangs[i + 1] || is_forced(nx.ch));
+    }
     for (i, g) in glyphs.iter().enumerate() {
         let prev_hang = if i > 0 { right_hang(&glyphs[i - 1], sp) } else { 0.0 };
+        if hangs[i] {
+            continue;
+        }
         if is_forced(g.ch) {
             it.push(Item::glue(0.0, INF, 0.0));
             ig.push(i);

crates/compose/src/tests.rs

@@ -2929,3 +2929,18 @@ fn empty_paragraphs_get_no_bullet_or_number() {
         assert_eq!(list_labels(&cs, LABEL_CHARS), ["1.", "", "2.", ""], "list `{name}`");
     }
 }
+
+#[test]
+fn spaces_at_the_end_of_a_paragraph_take_no_room() {
+    // A frame as wide as "2 VOOR" also holds "2 VOOR " on one line: the trailing space hangs.
+    let (d, sid, _) = doc_with("2 VOOR", Rect::new(0.0, 0.0, 500.0, 100.0), ParaAttrs::default());
+    let cs = compose_story(&d, sid, &ComposeOptions::default());
+    let l = all_lines(&cs)[0];
+    let width = l.end_x - l.x0;
+    for text in ["2 VOOR ", "2 VOOR  ", "2 VOOR \u{2028}more"] {
+        let (d, sid, _) = doc_with(text, Rect::new(0.0, 0.0, width + 0.02, 100.0), ParaAttrs::default());
+        let cs = compose_story(&d, sid, &ComposeOptions::default());
+        let first = all_lines(&cs)[0];
+        assert_eq!(&text[first.range.clone()].trim_end(), &"2 VOOR", "{text:?}");
+    }
+}