Merge pull request #3762 from Silvertree2010/fix/3590-audit-dxf-import-hatch-source-ha

Stop DXF hatch source-handle loop at first missing handle

crates/cad/src/import/entity.rs

@@ -536,7 +536,9 @@ fn boundary(c: &mut Cursor<'_, '_>) -> Option<BezPath> {
     // The boundary objects it was made from.
     if let Some(n) = c.count(97) {
         for _ in 0..n {
-            c.opt(330);
+            if c.opt(330).is_none() {
+                break;
+            }
         }
     }
     Some(bp)

crates/cad/src/import/tests.rs

@@ -380,6 +380,27 @@ fn solid_hatches_fill_and_pattern_hatches_outline() {
     assert!(square.appearance.fill().is_some_and(|f| !f.paint.is_none()));
 }
 
+#[test]
+fn hatch_declaring_many_absent_source_handles_parses_quickly() {
+    let base = hatch("1");
+    let at = |code: i32, from: usize| from + base[from..].iter().position(|p| p.0 == code).unwrap();
+    let first = at(92, 0);
+    let end = at(97, first) + 1;
+    let mut boundary = base[first..end].to_vec();
+    *boundary.last_mut().unwrap() = (97, "10000000");
+    let n = 300;
+    let mut e: Vec<(i32, &'static str)> = base[..first].to_vec();
+    e[at(91, 0)] = (91, "300");
+    for _ in 0..n {
+        e.extend_from_slice(&boundary);
+    }
+    e.extend_from_slice(&base[end..]);
+    let start = std::time::Instant::now();
+    let r = open(&entities(&e), &points());
+    assert!(start.elapsed() < std::time::Duration::from_millis(400), "took {:?}", start.elapsed());
+    assert_eq!(r.document.layers[0].children().unwrap().len(), 1, "{:?}", r.warnings);
+}
+
 /// A solid hatch: a loop of a line and a spline edge (`fit` its fit data, if any), followed by
 /// `source` (the loop's source-object count and handles), and a square hole.
 fn spline_edged_hatch(fit: &[(i32, &'static str)], source: &[(i32, &'static str)]) -> Vec<(i32, &'static str)> {