From 958566468abb925cd45bfd6a9fcdf6346a9e07b1 Mon Sep 17 00:00:00 2001
From: dotCooCoo <RobertLeeLW@gmail.com>
Date: Sat, 31 Oct 2026 00:29:28 -0700
Subject: [PATCH] DXF export: dashed polylines continue their linetype around
 vertices

A polyline with a linetype now sets group 70 bit 128, so the dash pattern runs on through its vertices instead of restarting at each corner. This applies to LWPOLYLINE and the R12 POLYLINE.
---
 crates/cad/src/scene.rs |  3 ++-
 crates/cad/src/tests.rs | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/crates/cad/src/scene.rs b/crates/cad/src/scene.rs
index a292d5a7f..34e69d6ed 100644
--- a/crates/cad/src/scene.rs
+++ b/crates/cad/src/scene.rs
@@ -872,7 +872,8 @@ impl<'a> Scene<'a> {
         let pts: Vec<Point> = pts.iter().map(|p| self.pt(*p)).collect();
         let layer = self.layer.clone();
         let h = self.handle();
-        let flags = i64::from(closed);
+        // Bit 128: a linetype runs on through the vertices instead of restarting at each one.
+        let flags = i64::from(closed) | if style.linetype.is_some() { 128 } else { 0 };
         if self.o.version.lwpolyline() {
             self.e.entity("LWPOLYLINE", h, fixed::MODEL_RECORD, &layer, style, "AcDbPolyline");
             self.e.int(90, pts.len() as i64);
diff --git a/crates/cad/src/tests.rs b/crates/cad/src/tests.rs
index aff8489c4..f02047492 100644
--- a/crates/cad/src/tests.rs
+++ b/crates/cad/src/tests.rs
@@ -696,6 +696,30 @@ fn dashes_that_start_part_way_into_their_pattern_are_outlined() {
     assert_eq!(get(&entities(&editable)[0], 6), Some("DASHED1"));
 }
 
+#[test]
+fn dashed_polylines_continue_their_pattern_around_corners() {
+    let rect = |dash: Option<Dash>| {
+        doc_with(|d| {
+            let mut n = path(d, shapes::rectangle(Rect::new(10.0, 10.0, 110.0, 60.0)), Paint::None, Paint::solid(Color::BLACK), 1.0);
+            if let Some(st) = n.appearance.stroke_mut() {
+                st.dash = dash.clone();
+            }
+            vec![n]
+        })
+    };
+    let flags = |out: &DxfOutput| entities(out).first().and_then(|e| get(e, 70).map(str::to_string));
+    // Group 70 bit 128 makes the linetype run on through the vertices instead of restarting
+    // at each one; a solid polyline keeps only its closed bit.
+    let dashed = rect(Some(Dash { pattern: vec![6.0, 3.0], offset: 0.0, align_corners: false }));
+    for o in [opts(&dashed), DxfOptions { alter_paths: true, ..opts(&dashed) }, DxfOptions { preserve: Preserve::Editability, ..opts(&dashed) }] {
+        assert_eq!(flags(&export(&dashed, &o).unwrap()).as_deref(), Some("129"));
+    }
+    let r12 = export(&dashed, &DxfOptions { version: DxfVersion::R12, ..opts(&dashed) }).unwrap();
+    assert_eq!((kinds(&r12).first().map(String::as_str), flags(&r12).as_deref()), (Some("POLYLINE"), Some("129")));
+    let solid = rect(None);
+    assert_eq!(flags(&export(&solid, &opts(&solid)).unwrap()).as_deref(), Some("1"));
+}
+
 fn text_doc(text: &str, size: f64) -> Document {
     doc_with(|d| {
         let style = CharStyle { size, fill: Paint::solid(Color::rgb(0.0, 0.5, 0.0)), ..CharStyle::default() };