Now update the retry logic to always retry with all ways, but filter rings with duplicate coordinates:


Edit

                                if (rings.empty()) {
                                    // Retry with all ways only when outer-only produced
                                    // 0 rings AND the relation has non-outer ways available.
                                    // Only retry when there are NO outer ways (the boundary IS
                                    // the inner ways). When outer ways exist but don't close,
                                    // including inner ways creates merged outer+hole geometry.
                                    bool has_outer_geom = false;
                                    for (const auto& [wid, role] : rel.members) {
                                        if (role == "outer" || role.empty()) {
                                            if (data.way_geometries.count(wid)) {
                                                has_outer_geom = true;
                                                break;
                                            }
                                        }
                                    }
                                    if (!has_outer_geom) {
                                        rings = assemble_outer_rings(rel.members, data.way_geometries, true);
                                    }
                                }

                                if (rings.empty()) {
                                    // Retry with all ways (inner + outer) when outer-only
                                    // fails. Osmium ignores roles during assembly. Inner ways
                                    // sometimes form the actual boundary or bridge gaps.
                                    // Filter out rings with duplicate coordinates — these are
                                    // figure-8 shapes from merging holes with outer boundary.
                                    auto retry_rings = assemble_outer_rings(rel.members, data.way_geometries, true);
                                    auto ck = [](double lat, double lng) -> int64_t {
                                        int32_t ilat = static_cast<int32_t>(lat * 1e7 + (lat >= 0 ? 0.5 : -0.5));
                                        int32_t ilng = static_cast<int32_t>(lng * 1e7 + (lng >= 0 ? 0.5 : -0.5));
                                        return (static_cast<int64_t>(ilat) << 32) | static_cast<uint32_t>(ilng);
                                    };
                                    for (auto& ring : retry_rings) {
                                        if (!ring_has_duplicate_coords(ring, ck)) {
                                            rings.push_back(std::move(ring));
                                        }
                                    }
                                }


<tool_use_error>String to replace not found in file.
String:                                 if (rings.empty()) {
                                    // Retry with all ways only when outer-only produced
                                    // 0 rings AND the relation has non-outer ways available.
                                    // Only retry when there are NO outer ways (the boundary IS
                                    // the inner ways). When outer ways exist but don't close,
                                    // including inner ways creates merged outer+hole geometry.
                                    bool has_outer_geom = false;
                                    for (const auto& [wid, role] : rel.members) {
                                        if (role == "outer" || role.empty()) {
                                            if (data.way_geometries.count(wid)) {
                                                has_outer_geom = true;
                                                break;
                                            }
                                        }
                                    }
                                    if (!has_outer_geom) {
                                        rings = assemble_outer_rings(rel.members, data.way_geometries, true);
                                    }
                                }</tool_use_error>

Error: String to replace not found in file.
String:                                 if (rings.empty()) {
                                    // Retry with all ways only when outer-only produced
                                    // 0 rings AND the relation has non-outer ways available.
                                    // Only retry when there are NO outer ways (the boundary IS
                                    // the inner ways). When outer ways exist but don't close,
                                    // including inner ways creates merged outer+hole geometry.
                                    bool has_outer_geom = false;
                                    for (const auto& [wid, role] : rel.members) {
                                        if (role == "outer" || role.empty()) {
                                            if (data.way_geometries.count(wid)) {
                                                has_outer_geom = true;
                                                break;
                                            }
                                        }
                                    }
                                    if (!has_outer_geom) {
                                        rings = assemble_outer_rings(rel.members, data.way_geometries, true);
                                    }
                                }


2534-                                if (has_missing) {
2535-                                    assembled_count.fetch_add(1);
2536-                                    continue;
2537-                                }
2538-
2539-                                auto rings = assemble_outer_rings(rel.members, data.way_geometries);
2540-                                // If outer-only assembly failed, retry with all ways.
2541-                                // Osmium ignores roles during assembly — inner ways
2542-                                // sometimes form the actual boundary or bridge gaps.
2543-                                if (rings.empty()) {
2544:                                    // Retry with all ways only when outer-only produced
2545-                                    // 0 rings AND the relation has non-outer ways available.
2546-                                    // Only retry when there are NO outer ways (the boundary IS
2547-                                    // the inner-role ways). When outer ways exist but don't close,
2548-                                    // including inner ways creates merged outer+hole geometry.
2549-                                    bool has_outer_geom = false;
2550-                                    for (const auto& [wid, role] : rel.members) {
2551-                                        if (role == "outer" || role.empty()) {
2552-                                            if (data.way_geometries.count(wid)) {
2553-                                                has_outer_geom = true;
2554-                                                break;


  2539→                                auto rings = assemble_outer_rings(rel.members, data.way_geometries);
  2540→                                // If outer-only assembly failed, retry with all ways.
  2541→                                // Osmium ignores roles during assembly — inner ways
  2542→                                // sometimes form the actual boundary or bridge gaps.
  2543→                                if (rings.empty()) {
  2544→                                    // Retry with all ways only when outer-only produced
  2545→                                    // 0 rings AND the relation has non-outer ways available.
  2546→                                    // Only retry when there are NO outer ways (the boundary IS
  2547→                                    // the inner-role ways). When outer ways exist but don't close,
  2548→                                    // including inner ways creates merged outer+hole geometry.
  2549→                                    bool has_outer_geom = false;
  2550→                                    for (const auto& [wid, role] : rel.members) {
  2551→                                        if (role == "outer" || role.empty()) {
  2552→                                            if (data.way_geometries.count(wid)) {
  2553→                                                has_outer_geom = true;
  2554→                                                break;
  2555→                                            }
  2556→                                        }
  2557→                                    }
  2558→                                    if (!has_outer_geom) {
  2559→                                        rings = assemble_outer_rings(rel.members, data.way_geometries, true);
  2560→                                    }
  2561→                                }
  2562→
  2563→                                // Diagnostic: log relations with 0 rings produced

                                auto rings = assemble_outer_rings(rel.members, data.way_geometries);
                                // If outer-only assembly failed, retry with all ways.
                                // Osmium ignores roles during assembly — inner ways
                                // sometimes form the actual boundary or bridge gaps.
                                if (rings.empty()) {
                                    // Retry with all ways only when outer-only produced
                                    // 0 rings AND the relation has non-outer ways available.
                                    // Only retry when there are NO outer ways (the boundary IS
                                    // the inner-role ways). When outer ways exist but don't close,
                                    // including inner ways creates merged outer+hole geometry.
                                    bool has_outer_geom = false;
                                    for (const auto& [wid, role] : rel.members) {
                                        if (role == "outer" || role.empty()) {
                                            if (data.way_geometries.count(wid)) {
                                                has_outer_geom = true;
                                                break;
                                            }
                                        }
                                    }
                                    if (!has_outer_geom) {
                                        rings = assemble_outer_rings(rel.members, data.way_geometries, true);
                                    }
                                }

                                // Diagnostic: log relations with 0 rings produced


                                auto rings = assemble_outer_rings(rel.members, data.way_geometries);
                                // If outer-only assembly failed, retry with all ways.
                                // Osmium ignores roles during assembly — inner ways
                                // sometimes form the actual boundary or bridge gaps.
                                if (rings.empty()) {
                                    // Retry with all ways only when outer-only produced
                                    // 0 rings AND the relation has non-outer ways available.
                                    // Only retry when there are NO outer ways (the boundary IS
                                    // the inner-role ways). When outer ways exist but don't close,
                                    // including inner ways creates merged outer+hole geometry.
                                    bool has_outer_geom = false;
                                    for (const auto& [wid, role] : rel.members) {
                                        if (role == "outer" || role.empty()) {
                                            if (data.way_geometries.count(wid)) {
                                                has_outer_geom = true;
                                                break;
                                            }
                                        }
                                    }
                                    if (!has_outer_geom) {
                                        rings = assemble_outer_rings(rel.members, data.way_geometries, true);
                                    }
                                }

                                auto rings = assemble_outer_rings(rel.members, data.way_geometries);
                                // If outer-only assembly failed, retry with all ways.
                                // Osmium ignores roles during assembly (check_roles=false) —
                                // inner ways sometimes form the boundary or bridge gaps.
                                // Filter retry results: discard rings with duplicate coords
                                // (figure-8 shapes from merging holes with outer boundary).
                                if (rings.empty()) {
                                    auto retry = assemble_outer_rings(rel.members, data.way_geometries, true);
                                    auto ck = [](double lat, double lng) -> int64_t {
                                        int32_t ilat = static_cast<int32_t>(lat * 1e7 + (lat >= 0 ? 0.5 : -0.5));
                                        int32_t ilng = static_cast<int32_t>(lng * 1e7 + (lng >= 0 ? 0.5 : -0.5));
                                        return (static_cast<int64_t>(ilat) << 32) | static_cast<uint32_t>(ilng);
                                    };
                                    for (auto& ring : retry) {
                                        if (!ring_has_duplicate_coords(ring, ck)) {
                                            rings.push_back(std::move(ring));
                                        }
                                    }
                                }