Refactor and fix takeover.c

Factor new takeover_unit() out of takeover_ship(), takeover_plane(),
takeover_land().  This fixes the following bugs in assault, attack,
board, lboard, paradrop and pboard:

* When the "land unit loaded on land unit" relation had a cycle,
  takeover_land() went into an infinite recursion.  Such cycles exist
  only in a corrupt game state.

* Nukes armed on planes weren't taken over along with their plane.
  Broken in commit 2e40a4bb, v4.3.3.

* Taking over land units with negative mobility increased mobility to
  zero.  Ditto planes embarked on ships or land units.

* Taking over planes embarked on ships or land units didn't clear
  their wing.

* Taking over planes and land units updated their MOB_ACCESS timestamp
  (pln_access, lnd_access), except for planes not embarked on
  anything.  This had no effect.

diff --git a/src/lib/subs/takeover.c b/src/lib/subs/takeover.c
index 2c23a077bfee8caf1ae2caee31b83365bdf1a0dc..6037e4bfe979a54474292096d3046efb6446968d 100644 (file)
--- a/src/lib/subs/takeover.c
+++ b/src/lib/subs/takeover.c
@@ -35,6 +35,7 @@
 #include <config.h>
 
 #include "file.h"
+#include "empobj.h"
 #include "game.h"
 #include "land.h"
 #include "lost.h"
@@ -48,6 +49,8 @@
 #include "ship.h"
 #include "xy.h"
 
+static void takeover_unit(struct empobj *, natid);
+
 void
 takeover(struct sctstr *sp, natid newown)
 {
@@ -200,96 +203,70 @@ takeover_plane(struct plnstr *pp, natid newown)
           prplane(pp),
           cname(newown), xyas(pp->pln_x, pp->pln_y, pp->pln_own));
     }
-    if (opt_MARKET)
-       trdswitchown(EF_PLANE, pp, newown);
-    if (pp->pln_mobil > 0)
-       pp->pln_mobil = 0;
-    pp->pln_own = newown;
-    pp->pln_mission = 0;
-    pp->pln_wing = 0;
-    putplane(pp->pln_uid, pp);
+    takeover_unit((struct empobj *)pp, newown);
 }
 
 void
 takeover_ship(struct shpstr *sp, natid newown)
 {
-    struct plnstr *pp;
-    struct lndstr *lp;
-    struct nstr_item ni;
-    struct plnstr p;
-    struct lndstr llp;
-
-    if (opt_MARKET)
-       trdswitchown(EF_SHIP, sp, newown);
-    sp->shp_own = newown;
-    sp->shp_mission = 0;
-    sp->shp_fleet = 0;
-    sp->shp_rflags = 0;
-    memset(sp->shp_rpath, 0, sizeof(sp->shp_rpath));
-    pp = &p;
-    lp = &llp;
-    /* Take over planes */
-    snxtitem_cargo(&ni, EF_PLANE, EF_SHIP, sp->shp_uid);
-    while (nxtitem(&ni, pp)) {
-       if (pp->pln_effic > PLANE_MINEFF)
-           pp->pln_effic = PLANE_MINEFF;
-       pp->pln_mobil = 0;
-       if (opt_MOB_ACCESS)
-           game_tick_to_now(&pp->pln_access);
-       if (opt_MARKET)
-           trdswitchown(EF_PLANE, pp, newown);
-       pp->pln_mission = 0;
-       pp->pln_own = newown;
-       putplane(pp->pln_uid, pp);
-    }
-    /* Take over land units */
-    snxtitem_cargo(&ni, EF_LAND, EF_SHIP, sp->shp_uid);
-    while (nxtitem(&ni, lp))
-       takeover_land(lp, newown);
-    putship(sp->shp_uid, sp);
+    takeover_unit((struct empobj *)sp, newown);
 }
 
 void
 takeover_land(struct lndstr *landp, natid newown)
 {
+    takeover_unit((struct empobj *)landp, newown);
+}
+
+static void
+takeover_unit(struct empobj *unit, natid newown)
+{
+    struct shpstr *sp;
     struct plnstr *pp;
     struct lndstr *lp;
+    int type;
     struct nstr_item ni;
-    struct plnstr p;
-    struct lndstr llp;
+    union empobj_storage cargo;
 
-    if (landp->lnd_effic < LAND_MINEFF) {
-       putland(landp->lnd_uid, landp);
-       return;
-    }
-    landp->lnd_army = 0;
-    landp->lnd_mobil = 0;
-    if (opt_MOB_ACCESS)
-       game_tick_to_now(&landp->lnd_access);
-    landp->lnd_harden = 0;
+    unit->own = newown;
     if (opt_MARKET)
-       trdswitchown(EF_LAND, landp, newown);
-    landp->lnd_mission = 0;
-    landp->lnd_own = newown;
-    pp = &p;
-    lp = &llp;
-    /* Take over planes */
-    snxtitem_cargo(&ni, EF_PLANE, EF_LAND, landp->lnd_uid);
-    while (nxtitem(&ni, pp)) {
-       if (pp->pln_effic > PLANE_MINEFF)
-           pp->pln_effic = PLANE_MINEFF;
-       pp->pln_mobil = 0;
-       if (opt_MOB_ACCESS)
-           game_tick_to_now(&pp->pln_access);
-       if (opt_MARKET)
-           trdswitchown(EF_PLANE, pp, newown);
-       pp->pln_mission = 0;
-       pp->pln_own = newown;
-       putplane(pp->pln_uid, pp);
+       trdswitchown(unit->ef_type, unit, newown);
+    unit->group = 0;
+    unit->mission = 0;
+
+    switch (unit->ef_type) {
+    case EF_SHIP:
+       sp = (struct shpstr *)unit;
+       sp->shp_rflags = 0;
+       memset(sp->shp_rpath, 0, sizeof(sp->shp_rpath));
+       break;
+    case EF_PLANE:
+       pp = (struct plnstr *)unit;
+       if (pp->pln_mobil > 0)
+           pp->pln_mobil = 0;
+       break;
+    case EF_LAND:
+       lp = (struct lndstr *)unit;
+       if (lp->lnd_mobil > 0)
+           lp->lnd_mobil = 0;
+       lp->lnd_harden = 0;
+       break;
+    case EF_NUKE:
+       break;
+    default:
+       CANT_REACH();
+    }
+
+    put_empobj(unit->ef_type, unit->uid, unit);
+
+    for (type = EF_PLANE; type <= EF_NUKE; type++) {
+       snxtitem_cargo(&ni, type, unit->ef_type, unit->uid);
+       while (nxtitem(&ni, &cargo)) {
+           if (cargo.gen.own == newown)
+               continue;
+           if (type == EF_PLANE)
+               cargo.plane.pln_effic = PLANE_MINEFF;
+           takeover_unit(&cargo.gen, newown);
+       }
     }
-    /* Take over land units */
-    snxtitem_cargo(&ni, EF_LAND, EF_LAND, landp->lnd_uid);
-    while (nxtitem(&ni, lp))
-       takeover_land(lp, newown);
-    putland(landp->lnd_uid, landp);
 }