fix: use get_element_bbox() in connectors rather than bbox()

Author: codedstructure

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Fixed: inconsistent polyline connectors with endpoints into transformed
+  groups.
+
 ## [0.26.0 - 2026-01-03]
 
 - Fixed: location references now respect transforms which may have moved

src/elements/connector.rs

@@ -329,11 +329,11 @@ impl Connector {
                 // inside Connector rather than evaluating it early)
                 let midpoint =
                     if let (Some(start_el), Some(end_el)) = (&self.start_el, &self.end_el) {
-                        let start_bb = start_el
-                            .bbox()?
+                        let start_bb = ctx
+                            .get_element_bbox(start_el)?
                             .ok_or_else(|| Error::MissingBBox(start_el.to_string()))?;
-                        let end_bb = end_el
-                            .bbox()?
+                        let end_bb = ctx
+                            .get_element_bbox(end_el)?
                             .ok_or_else(|| Error::MissingBBox(end_el.to_string()))?;
                         let overlap_top = start_bb
                             .scalarspec(ScalarSpec::Miny)
@@ -420,12 +420,12 @@ impl Connector {
                 let mut start_el_bb = BoundingBox::new(x1, y1, x1, y1);
                 let mut end_el_bb = BoundingBox::new(x2, y2, x2, y2);
                 if let Some(el) = &self.start_el {
-                    if let Ok(Some(el_bb)) = el.bbox() {
+                    if let Ok(Some(el_bb)) = ctx.get_element_bbox(el) {
                         start_el_bb = el_bb;
                     }
                 }
                 if let Some(el) = &self.end_el {
-                    if let Ok(Some(el_bb)) = el.bbox() {
+                    if let Ok(Some(el_bb)) = ctx.get_element_bbox(el) {
                         end_el_bb = el_bb;
                     }
                 }
@@ -439,7 +439,7 @@ impl Connector {
                     abs_offset_set,
                 )?;
 
-                // TODO: remove repeated points.
+                // TODO: remove repeated and collinear points.
                 if points.len() == 2 {
                     SvgElement::new(
                         "line",

tests/integration_tests/connector.rs

@@ -314,3 +314,15 @@ fn test_elbow_connector() {
     assert_contains!(output, expected1);
     assert_contains!(output, expected2);
 }
+
+#[test]
+fn test_connector_into_relpos_group() {
+    let input = r##"
+<g id="a"><rect id="a1" wh="10"/></g>
+<g id="b" xy="#a|h 20" dy="5"><rect id="b1" wh="10" /></g>
+<polyline start="#a1@r" end="#b1@l"/>
+"##;
+    let expected_line = r#"<polyline points="10 5, 20 5, 20 10, 30 10"/>"#;
+    let output = transform_str_default(input).unwrap();
+    assert_contains!(output, expected_line);
+}