+ return 0;
+
+ pending_block = 0;
+
+ // See how many blocks we already have
+ unsigned nsens = 0;
+ for(list<BlockRef>::const_iterator i=rsv_blocks.begin(); i!=rsv_blocks.end(); ++i)
+ if(i->block->get_sensor_id())
+ ++nsens;
+
+ bool got_more = false;
+ BlockRef *good = last;
+ unsigned good_sens = nsens;
+ while(good_sens<3)
+ {
+ // Traverse to the next block
+ unsigned exit = last->block->traverse(last->entry);
+ Block *link = last->block->get_link(exit);
+ if(!link)
+ break;
+
+ int entry = link->get_endpoint_by_link(*last->block);
+ if(entry<0)
+ throw LogicError("Block links are inconsistent!");
+ if(!link->reserve(this))
+ {
+ // If we found another train and it's not headed straight for us, we can keep the blocks we got
+ int other_entry = link->get_train()->get_entry_to_block(*link);
+ if(other_entry<0)
+ throw LogicError("Block reservation inconsistency");
+ if(static_cast<unsigned>(entry)!=link->traverse(other_entry))
+ {
+ good = last;
+ good_sens = nsens;
+ }
+ pending_block = link;
+ break;
+ }
+
+ if(link->get_turnout_id())
+ {
+ const Block::Endpoint &ep = link->get_endpoints()[entry];
+ const Endpoint &track_ep = ep.track->get_type().get_endpoints()[ep.track_ep];
+
+ // Keep the blocks reserved so far, as either us or the other train can diverge
+ good = last;
+ good_sens = nsens;
+
+ Turnout &turnout = trfc_mgr.get_control().get_turnout(link->get_turnout_id());
+
+ // Figure out what path we'd like to take on the turnout
+ int path = -1;
+ if(route)
+ path = route->get_turnout(link->get_turnout_id());
+ if(path<0)
+ path = turnout.get_path();
+ if(!((track_ep.paths>>path)&1))
+ {
+ for(unsigned i=0; track_ep.paths>>i; ++i)
+ if((track_ep.paths>>i)&1)
+ path = i;
+ }
+
+ if(path!=turnout.get_path())
+ {
+ // The turnout is set to wrong path - switch and wait for it
+ link->reserve(0);
+ pending_block = link;
+ turnout.set_path(path);
+ break;
+ }
+ }
+
+ rsv_blocks.push_back(BlockRef(link, entry));
+ last = &rsv_blocks.back();
+ if(last->block->get_sensor_id())
+ {
+ ++nsens;
+ got_more = true;
+ }
+ }
+
+ // Unreserve blocks that were not good
+ while(!rsv_blocks.empty() && last!=good)
+ {
+ last->block->reserve(0);
+ rsv_blocks.erase(--rsv_blocks.end());
+ if(!rsv_blocks.empty())
+ last = &rsv_blocks.back();
+ }