From 0cab5fcc1f99e6ca3dadf3c220a20e36b2a8c7c6 Mon Sep 17 00:00:00 2001 From: Ihnatus Date: Mon, 7 Jul 2025 23:31:13 +0300 Subject: [PATCH] Correct airlift action possibility check Don't airlift on non-allied unit tile. Consider airlift to ally cities not blocked by counters if it is nowhere. See RM#1564 Signed-off-by: Ihnatus --- common/movement.c | 44 +++++++++++++++++++++++++ common/movement.h | 4 +++ common/unit.c | 81 +++++++++++++++++++++++++++------------------- server/unittools.c | 2 +- 4 files changed, 96 insertions(+), 35 deletions(-) diff --git a/common/movement.c b/common/movement.c index 034cc98dc7..a64ac325a8 100644 --- a/common/movement.c +++ b/common/movement.c @@ -310,6 +310,50 @@ bool can_exist_at_tile(const struct civ_map *nmap, return is_native_tile(utype, ptile); } +/************************************************************************//** + Return if a unit of utype could possibly "exist" at the city tile of pcity + given the information known to pov_player. pcity is presumed to exist. + nmap is supposed to be client map. + This means it can physically be present on the tile (without the use of a + transporter). See can_exist_at_tile() for the omniscient check. +****************************************************************************/ +bool could_exist_in_city(const struct civ_map *nmap, + const struct player *pov_player, + const struct unit_type *utype, + const struct city *pcity) +{ + struct unit_class *uclass; + struct tile *ctile; + + fc_assert_ret_val(nullptr != pcity && nullptr != utype, FALSE); + + ctile = city_tile(pcity); + uclass = utype_class(utype); + + if (uclass_has_flag(uclass, UCF_BUILD_ANYWHERE)) { + /* If the city stands, it can exist there */ + return TRUE; + } + adjc_iterate(nmap, ctile, ptile) { + if (!tile_is_seen(ptile, pov_player) + || is_native_tile_to_class(uclass, ptile)) { + /* Could be native. This ignores a rare case when we don't see + * only the city center and any native terrain is NoCities */ + return TRUE; + } + } adjc_iterate_end; + + if (1 == game.info.citymindist + && is_city_channel_tile(nmap, uclass, ctile, nullptr)) { + /* FIXME: false negative results for city channels might appear */ + /* Channeled. */ + return TRUE; + } + + /* It definitely can't exist there */ + return FALSE; +} + /************************************************************************//** Return TRUE iff the unit can "exist" at this location. This means it can physically be present on the tile (without the use of a transporter). See diff --git a/common/movement.h b/common/movement.h index 611b679383..351e2ae298 100644 --- a/common/movement.h +++ b/common/movement.h @@ -98,6 +98,10 @@ bool is_native_near_tile(const struct civ_map *nmap, bool can_exist_at_tile(const struct civ_map *nmap, const struct unit_type *utype, const struct tile *ptile); +bool could_exist_in_city(const struct civ_map *nmap, + const struct player *pov_player, + const struct unit_type *utype, + const struct city *pcity); bool can_unit_exist_at_tile(const struct civ_map *nmap, const struct unit *punit, const struct tile *ptile); bool can_unit_survive_at_tile(const struct civ_map *nmap, diff --git a/common/unit.c b/common/unit.c index 8b5084be0d..dd40303530 100644 --- a/common/unit.c +++ b/common/unit.c @@ -85,11 +85,13 @@ enum unit_airlift_result { const struct city *psrc_city = tile_city(unit_tile(punit)); const struct player *punit_owner; + const struct tile *dst_tile = nullptr; + const struct unit_type *putype = unit_type_get(punit); + bool flagless = utype_has_flag(putype, UTYF_FLAGLESS); enum unit_airlift_result ok_result = AR_OK; if (0 == punit->moves_left - && !utype_may_act_move_frags(unit_type_get(punit), - ACTION_AIRLIFT, 0)) { + && !utype_may_act_move_frags(putype, ACTION_AIRLIFT, 0)) { /* No moves left. */ return AR_NO_MOVES; } @@ -103,7 +105,7 @@ enum unit_airlift_result return AR_OCCUPIED; } - if (NULL == psrc_city) { + if (nullptr == psrc_city) { /* No city there. */ return AR_NOT_IN_CITY; } @@ -113,13 +115,15 @@ enum unit_airlift_result return AR_BAD_DST_CITY; } - if (pdest_city - && (NULL == restriction - || (tile_get_known(city_tile(pdest_city), restriction) - == TILE_KNOWN_SEEN)) - && !can_unit_exist_at_tile(nmap, punit, city_tile(pdest_city))) { - /* Can't exist at the destination tile. */ - return AR_BAD_DST_CITY; + if (nullptr != pdest_city) { + dst_tile = city_tile(pdest_city); + + if (nullptr != restriction + ? !can_exist_at_tile(nmap, putype, dst_tile) + : !could_exist_in_city(nmap, restriction, putype, pdest_city)) { + /* Can't exist at the destination tile. */ + return AR_BAD_DST_CITY; + } } punit_owner = unit_owner(punit); @@ -134,35 +138,44 @@ enum unit_airlift_result return AR_BAD_SRC_CITY; } - if (pdest_city - && punit_owner != city_owner(pdest_city) - && !(game.info.airlifting_style & AIRLIFTING_ALLIED_DEST - && pplayers_allied(punit_owner, city_owner(pdest_city)))) { - /* Not allowed to airlift to this destination. */ - return AR_BAD_DST_CITY; + /* Check diplomatic possibility of the destination */ + if (nullptr != pdest_city) { + if (punit_owner != city_owner(pdest_city)) { + if (!(game.info.airlifting_style & AIRLIFTING_ALLIED_DEST + && pplayers_allied(punit_owner, city_owner(pdest_city))) + || flagless || is_non_allied_unit_tile(dst_tile, punit_owner, FALSE)) { + /* Not allowed to airlift to this destination. */ + return AR_BAD_DST_CITY; + } + } else if (flagless + && is_non_allied_unit_tile(dst_tile, punit_owner, TRUE)) { + /* Foreign units block airlifting to this destination */ + return AR_BAD_DST_CITY; + } } - if (NULL == restriction || city_owner(psrc_city) == restriction) { - /* We know for sure whether or not src can airlift this turn. */ - if (0 >= psrc_city->airlift - && (!(game.info.airlifting_style & AIRLIFTING_UNLIMITED_SRC) - || !game.info.airlift_from_always_enabled)) { - /* The source cannot airlift for this turn (maybe already airlifted - * or no airport). - * See also do_airline() in server/unittools.h. */ - return AR_SRC_NO_FLIGHTS; - } /* else, there is capacity; continue to other checks */ - } else { - /* We don't have access to the 'airlift' field. Assume it's OK; can - * only find out for sure by trying it. */ - ok_result = AR_OK_SRC_UNKNOWN; + /* Check airlift capacities */ + if (!game.info.airlift_from_always_enabled) { + if (nullptr == restriction || city_owner(psrc_city) == restriction) { + /* We know for sure whether or not src can airlift this turn. */ + if (0 >= psrc_city->airlift + && !(game.info.airlifting_style & AIRLIFTING_UNLIMITED_SRC)) { + /* The source cannot airlift for this turn (maybe already airlifted + * or no airport). + * See also do_airline() in server/unittools.h. */ + return AR_SRC_NO_FLIGHTS; + } /* else, there is capacity; continue to other checks */ + } else { + /* We don't have access to the 'airlift' field. Assume it's OK; can + * only find out for sure by trying it. */ + ok_result = AR_OK_SRC_UNKNOWN; + } } - if (pdest_city) { - if (NULL == restriction || city_owner(pdest_city) == restriction) { + if (nullptr != pdest_city && !game.info.airlift_to_always_enabled) { + if (nullptr == restriction || city_owner(pdest_city) == restriction) { if (0 >= pdest_city->airlift - && (!(game.info.airlifting_style & AIRLIFTING_UNLIMITED_DEST) - || !game.info.airlift_to_always_enabled)) { + && !(game.info.airlifting_style & AIRLIFTING_UNLIMITED_DEST)) { /* The destination cannot support airlifted units for this turn * (maybe already airlifted or no airport). * See also do_airline() in server/unittools.h. */ diff --git a/server/unittools.c b/server/unittools.c index 8e0cf8d8e3..b7f279d890 100644 --- a/server/unittools.c +++ b/server/unittools.c @@ -4072,7 +4072,7 @@ static struct unit_move_data_list *construct_move_data_list(struct unit *punit, /**********************************************************************//** Moves a unit. No checks whatsoever! This is meant as a practical function for other functions, like do_airline(), which do the checking - themselves. + either by themselves or by their callers If you move a unit you should always use this function, as it also sets the transport status of the unit correctly. Note that the source tile (the -- 2.45.2