Fix dangling chain bug.

If a punished player picks up the iron ball, gets engulfed and
saves, then the saved game will have missed saving the dangling
chain since it was not on the floor or in the inventory.  Upon
restoring the saved game, the game will be in a bad state since
the ball will be worn but the chain will be missing.

include/hack.h

@@ -436,6 +436,7 @@ enum bodypart_types {
 #define POTION_OCCUPANT_CHANCE(n) (13 + 2 * (n))
 #define WAND_BACKFIRE_CHANCE 100
 #define BALL_IN_MON (u.uswallow && uball && uball->where == OBJ_FREE)
+#define CHAIN_IN_MON (u.uswallow && uchain && uchain->where == OBJ_FREE)
 #define NODIAG(monnum) ((monnum) == PM_GRID_BUG)
 
 /* Flags to control menus */

src/restore.c

@@ -540,7 +540,8 @@ unsigned int *stuckid, *steedid;
     struct sysflag newgamesysflags;
 #endif
     struct context_info newgamecontext; /* all 0, but has some pointers */
-    struct obj *otmp, *tmp_bc;
+    struct obj *otmp;
+    struct obj *bc_obj;
     char timebuf[15];
     unsigned long uid;
     boolean defer_perm_invent;
@@ -643,17 +644,15 @@ unsigned int *stuckid, *steedid;
     restore_timers(fd, RANGE_GLOBAL, FALSE, 0L);
     restore_light_sources(fd);
     invent = restobjchn(fd, FALSE, FALSE);
-    /* tmp_bc only gets set here if the ball & chain were orphaned
+
-       because you were swallowed; otherwise they will be on the floor
+    /* restore dangling (not on floor or in inventory) ball and/or chain */
-       or in your inventory */
+    bc_obj = restobjchn(fd, FALSE, FALSE);
-    tmp_bc = restobjchn(fd, FALSE, FALSE);
+    while(bc_obj) {
-    if (tmp_bc) {
+        struct obj * nobj = bc_obj->nobj;
-        for (otmp = tmp_bc; otmp; otmp = otmp->nobj) {
+        if (bc_obj->owornmask)
-            if (otmp->owornmask)
+            setworn(bc_obj, bc_obj->owornmask);
-                setworn(otmp, otmp->owornmask);
+        bc_obj->nobj = (struct obj *)0;
-        }
+        bc_obj = nobj;
-        if (!uball || !uchain)
-            impossible("restgamestate: lost ball & chain");
     }
 
     migrating_objs = restobjchn(fd, FALSE, FALSE);
@@ -671,6 +670,10 @@ unsigned int *stuckid, *steedid;
     for (otmp = invent; otmp; otmp = otmp->nobj)
         if (otmp->owornmask)
             setworn(otmp, otmp->owornmask);
+
+    if ((uball && !uchain) || (uchain && !uball))
+        impossible("restgamestate: lost ball & chain");
+
     /* reset weapon so that player will get a reminder about "bashing"
        during next fight when bare-handed or wielding an unconventional
        item; for pick-axe, we aren't able to distinguish between having

src/save.c

@@ -280,6 +280,7 @@ savegamestate(fd, mode)
 register int fd, mode;
 {
     unsigned long uid;
+    struct obj * bc_objs = (struct obj *)0;
 
 #ifdef MFLOPPY
     count_only = (mode & COUNT_SAVE);
@@ -307,14 +308,18 @@ register int fd, mode;
     save_light_sources(fd, mode, RANGE_GLOBAL);
 
     saveobjchn(fd, invent, mode);
-    if (BALL_IN_MON) {
+
-        /* prevent loss of ball & chain when swallowed */
+    /* save ball and chain if they are currently dangling free (i.e. not on
-        uball->nobj = uchain;
+       floor or in inventory) */
-        uchain->nobj = (struct obj *) 0;
+    if (CHAIN_IN_MON) {
-        saveobjchn(fd, uball, mode);
+        uchain->nobj = bc_objs;
-    } else {
+        bc_objs = uchain;
-        saveobjchn(fd, (struct obj *) 0, mode);
     }
+    if (BALL_IN_MON) {
+        uball->nobj = bc_objs;
+        bc_objs = uball;
+    }
+    saveobjchn(fd, bc_objs, mode);
 
     saveobjchn(fd, migrating_objs, mode);
     savemonchn(fd, migrating_mons, mode);