cant delete roads involving turn restrictions

map_editor/src/main.rs

@@ -400,5 +400,5 @@ impl GUI for UI {
 }
 
 fn main() {
-    ezgui::run("Synthetic map editor", 1024.0, 768.0, |ctx| UI::new(ctx));
+    ezgui::run("Synthetic map editor", 1800.0, 800.0, |ctx| UI::new(ctx));
 }

map_editor/src/model.rs

@@ -455,8 +455,15 @@ impl Model {
 
     pub fn delete_r(&mut self, id: StableRoadID) {
         assert!(self.showing_pts != Some(id));
-        self.road_deleted(id);
-        self.map.delete_road(id, &mut self.fixes);
+        if self.map.can_delete_road(id) {
+            self.road_deleted(id);
+            self.map.delete_road(id, &mut self.fixes);
+        } else {
+            println!(
+                "Can't delete {}, it must have turn restriction from/to it",
+                id
+            );
+        }
     }
 
     pub fn get_road_spec(&self, id: StableRoadID) -> String {

map_model/src/raw.rs

@@ -225,7 +225,24 @@ impl RawMap {
 
 // Mutations
 impl RawMap {
+    pub fn can_delete_road(&self, r: StableRoadID) -> bool {
+        if !self.get_turn_restrictions(r).is_empty() {
+            return false;
+        }
+        // Brute force search the other direction
+        let osm_id = self.roads[&r].orig_id.osm_way_id;
+        for restrictions in self.turn_restrictions.values() {
+            for (_, to) in restrictions {
+                if *to == osm_id {
+                    return false;
+                }
+            }
+        }
+        true
+    }
+
     pub fn delete_road(&mut self, r: StableRoadID, fixes: &mut MapFixes) {
+        assert!(self.can_delete_road(r));
         let road = self.roads.remove(&r).unwrap();
         if !road.synthetic() {
             fixes.delete_roads.push(road.orig_id);