Fix disembarking without losing MP through adjacent transport

common/map.cpp

@@ -759,19 +759,9 @@ int tile_move_cost_ptrs(const struct civ_map *nmap, const struct unit *punit,
 
   } else if (!is_native_tile_to_class(pclass, t2)
              || !is_native_tile_to_class(pclass, t1)) {
-    if (tile_city(t1) == nullptr) {
-      /* Loading to/disembarking from transport. */
-
-      // UTYF_IGTER units get move benefit.
-      return (utype_has_flag(punittype, UTYF_IGTER) ? MOVE_COST_IGTER
-                                                    : SINGLE_MOVE);
-    } else {
-      /* Entering/leaving port. */
-
-      // UTYF_IGTER units get move benefit.
-      return (utype_has_flag(punittype, UTYF_IGTER) ? MOVE_COST_IGTER
-                                                    : SINGLE_MOVE);
-    }
+    // UTYF_IGTER units get move benefit.
+    return (utype_has_flag(punittype, UTYF_IGTER) ? MOVE_COST_IGTER
+                                                  : SINGLE_MOVE);
   }
 
   cost = tile_terrain(t2)->movement_cost * SINGLE_MOVE;

common/path.h

@@ -3,7 +3,7 @@
 
 #pragma once
 
-#include <unit.h>
+#include "unit.h"
 
 #include <vector>
 

common/path_finder.cpp

@@ -397,26 +397,27 @@ void path_finder::path_finder_private::attempt_unload(detail::vertex &source)
     // Nearby tiles
     adjc_iterate(&(wld.map), probe.tile, target)
     {
-      if (is_action_enabled_unit_on_tile(ACTION_TRANSPORT_DISEMBARK1, &probe,
-                                         target, nullptr)) {
-        auto next = source.child_for_action(ACTION_TRANSPORT_DISEMBARK1,
-                                            probe, target);
-        next.moved = true;
-        next.loaded = nullptr;
-        // See unithand.cpp:do_disembark
-        next.moves_left -= map_move_cost_unit(&(wld.map), &probe, target);
-        maybe_insert_vertex(next);
-      }
       // Thanks sveinung
-      if (is_action_enabled_unit_on_tile(ACTION_TRANSPORT_DISEMBARK2, &probe,
-                                         target, nullptr)) {
-        auto next = source.child_for_action(ACTION_TRANSPORT_DISEMBARK2,
-                                            probe, target);
-        next.moved = true;
-        next.loaded = nullptr;
-        // See unithand.cpp:do_disembark
-        next.moves_left -= map_move_cost_unit(&(wld.map), &probe, target);
-        maybe_insert_vertex(next);
+      for (auto action :
+           {ACTION_TRANSPORT_DISEMBARK1, ACTION_TRANSPORT_DISEMBARK2}) {
+        if (is_action_enabled_unit_on_tile(action, &probe, target,
+                                           nullptr)) {
+          auto next = source.child_for_action(action, probe, target);
+          next.moved = true;
+          // See unithand.cpp:do_disembark
+          next.moves_left -= map_move_cost_unit(&(wld.map), &probe, target);
+
+          if (can_unit_survive_at_tile(&(wld.map), &probe, target)) {
+            next.loaded = nullptr;
+          } else {
+            // Unit need to load in a transport to survive
+            // FIXME Should consider some action enabler here... Server side
+            // code doesn't do it.
+            next.loaded = transporter_for_unit_at(&probe, target);
+          }
+
+          maybe_insert_vertex(next);
+        }
       }
     }
     adjc_iterate_end;

server/unithand.cpp

@@ -645,7 +645,7 @@ static bool do_disembark(struct player *act_player, struct unit *act_unit,
   fc_assert_ret_val(tgt_tile, false);
   fc_assert_ret_val(paction, false);
 
-  unit_move(act_unit, tgt_tile, move_cost, nullptr, false, false);
+  unit_move(act_unit, tgt_tile, move_cost, nullptr, true, false);
 
   return true;
 }

server/unittools.cpp

@@ -2522,7 +2522,7 @@ void kill_unit(struct unit *pkiller, struct unit *punit, bool vet)
             /* FIXME: Shouldn't unit_move_handling() be used here? This is
              * the unit escaping by moving itself. It should therefore
              * respect movement rules. */
-            unit_move(vunit, dsttile, move_cost, nullptr, false, false);
+            unit_move(vunit, dsttile, move_cost, nullptr, true, false);
             num_escaped[player_index(vplayer)]++;
             escaped = true;
             unitcount--;