boulders vs vault walls

Noticed when testing the "wall_angle: unknown" fix, if there is a
boulder rather than a door in the breach in a vault's walls at the
spot where the guard arrives, the guard would walk onto it, tell the
hero to drop any gold and follow, then move back.  The boulder would
remain in the hero's way and couldn't be pushed because the guard was
in the boulder's way.  Have the guard smash any such boulder(s) into
rocks when arriving (with no explanation for how that is accomplished,
just a message about seeing or hearing boulder(s) shatter).  Later
when repairing the walls, delete any rocks or boulders at all vault
wall locations (even when no gap-to-wall repair is needed).

src/vault.c

@@ -293,6 +293,7 @@ void
 invault(void)
 {
     struct monst *guard;
+    struct obj *otmp;
     boolean gsensed;
     int trycount, vaultroom = (int) vault_occupied(u.urooms);
 
@@ -381,6 +382,25 @@ invault(void)
         EGD(guard)->warncnt = 0;
 
         reset_faint(); /* if fainted - wake up */
+        /* if there are any boulders in the guard's way, destroy them;
+           perhaps the guard knows a touch equivalent of force bolt;
+           otherwise the hero wouldn't be able to push one to follow the
+           guard out of the vault because that guard would be in its way */
+        if ((otmp = sobj_at(BOULDER, guard->mx, guard->my)) != 0) {
+            void (*func)(const char *, ...) PRINTF_F(1, 2);
+            const char *bname = simpleonames(otmp);
+            int bcnt = 0;
+
+            do {
+                ++bcnt;
+                fracture_rock(otmp);
+                otmp = sobj_at(BOULDER, guard->mx, guard->my);
+            } while (otmp);
+            /* You_hear() will handle Deaf/!Deaf */
+            func = !Blind ? You_see : You_hear;
+            (*func)("%s shatter.",
+                    (bcnt == 1) ? an(bname) : makeplural(bname));
+        }
         gsensed = !canspotmon(guard);
         if (!gsensed)
             pline("Suddenly one of the Vault's %s enters!",
@@ -388,6 +408,7 @@ invault(void)
         else
             pline("Someone else has entered the Vault.");
         newsym(guard->mx, guard->my);
+
         if (u.uswallow) {
             /* can't interrogate hero, don't interrogate engulfer */
             if (!Deaf)
@@ -569,7 +590,7 @@ wallify_vault(struct monst *grd)
     xchar lox = g.rooms[vlt].lx - 1, hix = g.rooms[vlt].hx + 1,
           loy = g.rooms[vlt].ly - 1, hiy = g.rooms[vlt].hy + 1;
     struct monst *mon;
-    struct obj *gold;
+    struct obj *gold, *rocks;
     struct trap *trap;
     boolean fixed = FALSE;
     boolean movedgold = FALSE;
@@ -580,18 +601,32 @@ wallify_vault(struct monst *grd)
             if (x != lox && x != hix && y != loy && y != hiy)
                 continue;
 
-            if (!IS_WALL(levl[x][y].typ) && !in_fcorridor(grd, x, y)) {
+            if ((!IS_WALL(levl[x][y].typ) || g_at(x, y)
+                 || sobj_at(ROCK, x, y) || sobj_at(BOULDER, x, y))
+                && !in_fcorridor(grd, x, y)) {
                 if ((mon = m_at(x, y)) != 0 && mon != grd) {
                     if (mon->mtame)
                         yelp(mon);
                     (void) rloc(mon, FALSE);
                 }
+                /* move gold at wall locations into the vault */
                 if ((gold = g_at(x, y)) != 0) {
                     move_gold(gold, EGD(grd)->vroom);
                     movedgold = TRUE;
                 }
+                /* destroy rocks and boulders (subsume them into the walls);
+                   other objects present stay intact and become embedded */
+                while ((rocks = sobj_at(ROCK, x, y)) != 0) {
+                    obj_extract_self(rocks);
+                    obfree(rocks, (struct obj *) 0);
+                }
+                while ((rocks = sobj_at(BOULDER, x, y)) != 0) {
+                    obj_extract_self(rocks);
+                    obfree(rocks, (struct obj *) 0);
+                }
                 if ((trap = t_at(x, y)) != 0)
                     deltrap(trap);
+
                 if (x == lox)
                     typ = (y == loy) ? TLCORNER
                           : (y == hiy) ? BLCORNER

src/zap.c

@@ -4466,14 +4466,7 @@ melt_ice(xchar x, xchar y, const char *msg)
     if (lev->typ == DRAWBRIDGE_UP || lev->typ == DRAWBRIDGE_DOWN) {
         lev->drawbridgemask &= ~DB_ICE; /* revert to DB_MOAT */
     } else { /* lev->typ == ICE */
-#ifdef STUPID
-        if (lev->icedpool == ICED_POOL)
-            lev->typ = POOL;
-        else
-            lev->typ = MOAT;
-#else
         lev->typ = (lev->icedpool == ICED_POOL ? POOL : MOAT);
-#endif
         lev->icedpool = 0;
     }
     spot_stop_timers(x, y, MELT_ICE_AWAY); /* no more ice to melt away */
@@ -4877,7 +4870,7 @@ zap_over_floor(xchar x, xchar y, int type, boolean *shopdamage,
     return rangemod;
 }
 
-/* fractured by pick-axe or wand of striking */
+/* fractured by pick-axe or wand of striking or by vault guard */
 void
 fracture_rock(struct obj *obj) /* no texts here! */
 {