Don't collapse an intersection with a crossing. #246

(It never happens in a test, so no known diff)

osm2streets/src/transform/collapse_intersections.rs

@@ -9,19 +9,26 @@ use crate::{IntersectionID, IntersectionKind, Placement, Road, StreetNetwork};
 /// Collapse degenerate intersections:
 /// - between two cycleways
 /// - when the lane specs, name, and layer match
+/// - when there's no crossing
 pub fn collapse(streets: &mut StreetNetwork) {
  let mut merge: Vec<IntersectionID> = Vec::new();
- for id in streets.intersections.keys() {
- let roads = streets.roads_per_intersection(*id);
+ for intersection in streets.intersections.values() {
+ if intersection.crossing.is_some() {
+ continue;
+ }
+ let roads = streets.roads_per_intersection(intersection.id);
  if roads.len() != 2 {
  continue;
  }
  match should_collapse(roads[0], roads[1]) {
  Ok(()) => {
- merge.push(*id);
+ merge.push(intersection.id);
  }
  Err(err) => {
- warn!("Not collapsing degenerate intersection {}: {}", id, err);
+ warn!(
+ "Not collapsing degenerate intersection {}: {}",
+ intersection.id, err
+ );
  }
  }
  }