fix #H6104 - no potion handling in thitu()

thitu() is mostly used for arrows and darts "thrown" by traps, but
scatter() uses it on items launched by a land mine explosion.  Traps
had no need for potion handling, but scattering does.  Changing thitu()
to call potionhit() required that more information be passed to the
latter in case killer reason was needed, and thitu()'s callers needed
to be updated since it now might use up its missile (only when that's
a potion, so scatter() is only caller which actually needed to care).

Quite a bit of work--especially the testing--for something which will
never be noticed in actual play.  In hindsight, it would have been
much simpler just to make scatter destroy all potions rather than
allow the 1% chance of remaining intact (via obj_resists()), or else
leave any intact ones at the explosion spot instead of launching them.

doc/fixes36.1

@@ -446,6 +446,8 @@ fix buffer overflow in wizard mode for '#' command when 'extmenu' option is on
 fix mention_walls reporting secret doors as solid walls
 corpses and other flammable items not subject to direct burning or fire-based
 	erosion which were thrown or dropped into lava remained intact
+if a potion on the floor survived a land mine explosion and got propelled at
+	the hero, it didn't behave like a potion if it hit
 
 
 Fixes to Post-3.6.0 Problems that Were Exposed Via git Repository

include/extern.h

@@ -1533,7 +1533,7 @@ E void FDECL(Delay, (int));
 
 /* ### mthrowu.c ### */
 
-E int FDECL(thitu, (int, int, struct obj *, const char *));
+E int FDECL(thitu, (int, int, struct obj **, const char *));
 E int FDECL(ohitmon, (struct monst *, struct obj *, int, BOOLEAN_P));
 E void FDECL(thrwmu, (struct monst *));
 E int FDECL(spitmu, (struct monst *, struct attack *));
@@ -1883,7 +1883,7 @@ E int FDECL(dopotion, (struct obj *));
 E int FDECL(peffects, (struct obj *));
 E void FDECL(healup, (int, int, BOOLEAN_P, BOOLEAN_P));
 E void FDECL(strange_feeling, (struct obj *, const char *));
-E void FDECL(potionhit, (struct monst *, struct obj *, BOOLEAN_P));
+E void FDECL(potionhit, (struct monst *, struct obj *, int));
 E void FDECL(potionbreathe, (struct obj *));
 E int NDECL(dodip);
 E void FDECL(mongrantswish, (struct monst **));

include/obj.h

@@ -40,7 +40,7 @@ struct obj {
     unsigned owt;
     long quan; /* number of items */
 
-    schar spe; /* quality of weapon, armor or ring (+ or -);
+    schar spe; /* quality of weapon, weptool, armor or ring (+ or -);
                   number of charges for wand or charged tool ( >= -1 );
                   marks your eggs, tin variety and spinach tins;
                   Schroedinger's Box (1) or royal coffers for a court (2);
@@ -373,6 +373,12 @@ struct obj {
 #define ER_DAMAGED 2   /* object was damaged in some way */
 #define ER_DESTROYED 3 /* object was destroyed */
 
+/* propeller method for potionhit() */
+#define POTHIT_HERO_BASH   0 /* wielded by hero */
+#define POTHIT_HERO_THROW  1 /* thrown by hero */
+#define POTHIT_MONST_THROW 2 /* thrown by a monster */
+#define POTHIT_OTHER_THROW 3 /* propelled by some other means [scatter()] */
+
 /*
  *  Notes for adding new oextra structures:
  *

src/apply.c

@@ -2786,9 +2786,8 @@ struct obj *obj;
                         int hitu, hitvalu;
 
                         hitvalu = 8 + otmp->spe;
-                        hitu = thitu(hitvalu,
+                        hitu = thitu(hitvalu, dmgval(otmp, &youmonst),
-                                     dmgval(otmp, &youmonst),
+                                     &otmp, (char *)0);
-                                     otmp, (char *)0);
                         if (hitu) {
                             pline_The("%s hits you as you try to snatch it!",
                                       the(onambuf));

src/dothrow.c

@@ -884,7 +884,7 @@ boolean hitsroof;
     /* object now hits you */
 
     if (obj->oclass == POTION_CLASS) {
-        potionhit(&youmonst, obj, TRUE);
+        potionhit(&youmonst, obj, POTHIT_HERO_THROW);
     } else if (breaktest(obj)) {
         int otyp = obj->otyp;
         int blindinc;
@@ -1086,7 +1086,7 @@ boolean
                    && rn2(6)) {
             /* alternative to prayer or wand of opening/spell of knock
                for dealing with cursed saddle:  throw holy water > */
-            potionhit(u.usteed, obj, TRUE);
+            potionhit(u.usteed, obj, POTHIT_HERO_THROW);
         } else {
             hitfloor(obj);
         }
@@ -1614,7 +1614,7 @@ register struct obj *obj; /* thrownobj or kickedobj or uwep */
 
     } else if (obj->oclass == POTION_CLASS
                && (guaranteed_hit || ACURR(A_DEX) > rnd(25))) {
-        potionhit(mon, obj, TRUE);
+        potionhit(mon, obj, POTHIT_HERO_THROW);
         return 1;
 
     } else if (befriend_with_obj(mon->data, obj)

src/explode.c

@@ -570,7 +570,7 @@ struct obj *obj; /* only scatter this obj        */
     struct scatter_chain *schain = (struct scatter_chain *) 0;
     long total = 0L;
 
-    while ((otmp = individual_object ? obj : level.objects[sx][sy]) != 0) {
+    while ((otmp = (individual_object ? obj : level.objects[sx][sy])) != 0) {
         if (otmp->quan > 1L) {
             qtmp = otmp->quan - 1L;
             if (qtmp > LARGEST_INT)
@@ -584,8 +584,8 @@ struct obj *obj; /* only scatter this obj        */
         used_up = FALSE;
 
         /* 9 in 10 chance of fracturing boulders or statues */
-        if ((scflags & MAY_FRACTURE)
+        if ((scflags & MAY_FRACTURE) != 0
-            && ((otmp->otyp == BOULDER) || (otmp->otyp == STATUE))
+            && (otmp->otyp == BOULDER || otmp->otyp == STATUE)
             && rn2(10)) {
             if (otmp->otyp == BOULDER) {
                 if (cansee(sx, sy))
@@ -614,7 +614,7 @@ struct obj *obj; /* only scatter this obj        */
             used_up = TRUE;
 
             /* 1 in 10 chance of destruction of obj; glass, egg destruction */
-        } else if ((scflags & MAY_DESTROY)
+        } else if ((scflags & MAY_DESTROY) != 0
                    && (!rn2(10) || (objects[otmp->otyp].oc_material == GLASS
                                     || otmp->otyp == EGG))) {
             if (breaks(otmp, (xchar) sx, (xchar) sy))
@@ -622,8 +622,7 @@ struct obj *obj; /* only scatter this obj        */
         }
 
         if (!used_up) {
-            stmp = (struct scatter_chain *)
+            stmp = (struct scatter_chain *) alloc(sizeof *stmp);
-                                         alloc(sizeof (struct scatter_chain));
             stmp->next = (struct scatter_chain *) 0;
             stmp->obj = otmp;
             stmp->ox = sx;
@@ -679,7 +678,9 @@ struct obj *obj; /* only scatter this obj        */
                         if (bigmonst(youmonst.data))
                             hitvalu++;
                         hitu = thitu(hitvalu, dmgval(stmp->obj, &youmonst),
-                                     stmp->obj, (char *) 0);
+                                     &stmp->obj, (char *) 0);
+                        if (!stmp->obj)
+                            stmp->stopped = TRUE;
                         if (hitu) {
                             stmp->range -= 3;
                             stop_occupation();

src/mthrowu.c

@@ -29,11 +29,12 @@ extern boolean notonhead; /* for long worms */
 
 /* hero is hit by something other than a monster */
 int
-thitu(tlev, dam, obj, name)
+thitu(tlev, dam, objp, name)
 int tlev, dam;
-struct obj *obj;
+struct obj **objp;
-const char *name; /* if null, then format `obj' */
+const char *name; /* if null, then format `*objp' */
 {
+    struct obj *obj = objp ? *objp : 0;
     const char *onm, *knm;
     boolean is_acid;
     int kprefix = KILLED_BY_AN;
@@ -42,8 +43,8 @@ const char *name; /* if null, then format `obj' */
     if (!name) {
         if (!obj)
             panic("thitu: name & obj both null?");
-        name =
+        name = strcpy(onmbuf,
-            strcpy(onmbuf, (obj->quan > 1L) ? doname(obj) : mshot_xname(obj));
+                      (obj->quan > 1L) ? doname(obj) : mshot_xname(obj));
         knm = strcpy(knmbuf, killer_xname(obj));
         kprefix = KILLED_BY; /* killer_name supplies "an" if warranted */
     } else {
@@ -70,14 +71,20 @@ const char *name; /* if null, then format `obj' */
         else
             You("are hit by %s%s", onm, exclam(dam));
 
-        if (obj && objects[obj->otyp].oc_material == SILVER && Hate_silver) {
-            /* extra damage already applied by dmgval() */
-            pline_The("silver sears your flesh!");
-            exercise(A_CON, FALSE);
-        }
         if (is_acid && Acid_resistance) {
             pline("It doesn't seem to hurt you.");
+        } else if (obj && obj->oclass == POTION_CLASS) {
+            /* an explosion which scatters objects might hit hero with one
+               (potions deliberately thrown at hero are handled by m_throw) */
+            potionhit(&youmonst, obj, POTHIT_OTHER_THROW);
+            *objp = obj = 0; /* potionhit() uses up the potion */
         } else {
+            if (obj && objects[obj->otyp].oc_material == SILVER
+                && Hate_silver) {
+                /* extra damage already applied by dmgval() */
+                pline_The("silver sears your flesh!");
+                exercise(A_CON, FALSE);
+            }
             if (is_acid)
                 pline("It burns!");
             losehp(dam, knm, kprefix); /* acid damage */
@@ -110,9 +117,9 @@ int x, y;
     else
         create = 1;
 
-    if (create
+    if (create && !((mtmp = m_at(x, y)) != 0 && mtmp->mtrapped
-        && !((mtmp = m_at(x, y)) && (mtmp->mtrapped) && (t = t_at(x, y))
+                    && (t = t_at(x, y)) != 0
-             && ((t->ttyp == PIT) || (t->ttyp == SPIKED_PIT)))) {
+                    && (t->ttyp == PIT || t->ttyp == SPIKED_PIT))) {
         int objgone = 0;
 
         if (down_gate(x, y) != -1)
@@ -329,7 +336,9 @@ boolean verbose;    /* give message(s) even when you can't see what happened */
         mtmp->msleeping = 0;
         if (vis)
             otmp->dknown = 1;
-        potionhit(mtmp, otmp, FALSE);
+        /* probably thrown by a monster rather than 'other', but the
+           distinction only matters when hitting the hero */
+        potionhit(mtmp, otmp, POTHIT_OTHER_THROW);
         return 1;
     } else {
         damage = dmgval(otmp, mtmp);
@@ -549,7 +558,7 @@ struct obj *obj;         /* missile (or stack providing it) */
             if (singleobj->oclass == POTION_CLASS) {
                 if (!Blind)
                     singleobj->dknown = 1;
-                potionhit(&youmonst, singleobj, FALSE);
+                potionhit(&youmonst, singleobj, POTHIT_MONST_THROW);
                 break;
             }
             oldumort = u.umortality;
@@ -565,7 +574,7 @@ struct obj *obj;         /* missile (or stack providing it) */
             /* fall through */
             case CREAM_PIE:
             case BLINDING_VENOM:
-                hitu = thitu(8, 0, singleobj, (char *) 0);
+                hitu = thitu(8, 0, &singleobj, (char *) 0);
                 break;
             default:
                 dam = dmgval(singleobj, &youmonst);
@@ -585,7 +594,7 @@ struct obj *obj;         /* missile (or stack providing it) */
                 hitv += 8 + singleobj->spe;
                 if (dam < 1)
                     dam = 1;
-                hitu = thitu(hitv, dam, singleobj, (char *) 0);
+                hitu = thitu(hitv, dam, &singleobj, (char *) 0);
             }
             if (hitu && singleobj->opoisoned && is_poisonable(singleobj)) {
                 char onmbuf[BUFSZ], knmbuf[BUFSZ];
@@ -888,7 +897,7 @@ struct monst *mtmp;
         if (dam < 1)
             dam = 1;
 
-        (void) thitu(hitv, dam, otmp, (char *) 0);
+        (void) thitu(hitv, dam, &otmp, (char *) 0);
         stop_occupation();
         return;
     }

src/potion.c

@@ -1243,24 +1243,28 @@ const char *objphrase; /* "Your widget glows" or "Steed's saddle glows" */
     return res;
 }
 
+/* potion obj hits monster mon, which might be youmounst; obj always use up */
 void
-potionhit(mon, obj, your_fault)
+potionhit(mon, obj, how)
-register struct monst *mon;
+struct monst *mon;
-register struct obj *obj;
+struct obj *obj;
-boolean your_fault;
+int how;
 {
     const char *botlnam = bottlename();
     boolean isyou = (mon == &youmonst);
     int distance, tx, ty;
     struct obj *saddle = (struct obj *) 0;
-    boolean hit_saddle = FALSE;
+    boolean hit_saddle = FALSE, your_fault = (how <= POTHIT_HERO_THROW);
 
     if (isyou) {
         tx = u.ux, ty = u.uy;
         distance = 0;
         pline_The("%s crashes on your %s and breaks into shards.", botlnam,
                   body_part(HEAD));
-        losehp(Maybe_Half_Phys(rnd(2)), "thrown potion", KILLED_BY_AN);
+        losehp(Maybe_Half_Phys(rnd(2)),
+               (how == POTHIT_OTHER_THROW) ? "propelled potion" /* scatter */
+                                           : "thrown potion",
+               KILLED_BY_AN);
     } else {
         tx = mon->mx, ty = mon->my;
         /* sometimes it hits the saddle */
@@ -1314,6 +1318,7 @@ boolean your_fault;
         case POT_ACID:
             if (!Acid_resistance) {
                 int dmg;
+
                 pline("This burns%s!",
                       obj->blessed ? " a little"
                                    : obj->cursed ? " a lot" : "");

src/trap.c

@@ -844,7 +844,7 @@ register struct trap *trap;
 unsigned trflags;
 {
     register int ttype = trap->ttyp;
-    register struct obj *otmp;
+    struct obj *otmp;
     boolean already_seen = trap->tseen,
             forcetrap = (trflags & FORCETRAP) != 0,
             webmsgok = (trflags & NOWEBMSG) == 0,
@@ -915,8 +915,9 @@ unsigned trflags;
         otmp->opoisoned = 0;
         if (u.usteed && !rn2(2) && steedintrap(trap, otmp)) { /* nothing */
             ;
-        } else if (thitu(8, dmgval(otmp, &youmonst), otmp, "arrow")) {
+        } else if (thitu(8, dmgval(otmp, &youmonst), &otmp, "arrow")) {
-            obfree(otmp, (struct obj *) 0);
+            if (otmp)
+                obfree(otmp, (struct obj *) 0);
         } else {
             place_object(otmp, u.ux, u.uy);
             if (!Blind)
@@ -944,13 +945,15 @@ unsigned trflags;
         oldumort = u.umortality;
         if (u.usteed && !rn2(2) && steedintrap(trap, otmp)) { /* nothing */
             ;
-        } else if (thitu(7, dmgval(otmp, &youmonst), otmp, "little dart")) {
+        } else if (thitu(7, dmgval(otmp, &youmonst), &otmp, "little dart")) {
-            if (otmp->opoisoned)
+            if (otmp) {
-                poisoned("dart", A_CON, "little dart",
+                if (otmp->opoisoned)
-                         /* if damage triggered life-saving,
+                    poisoned("dart", A_CON, "little dart",
-                            poison is limited to attrib loss */
+                             /* if damage triggered life-saving,
-                         (u.umortality > oldumort) ? 0 : 10, TRUE);
+                                poison is limited to attrib loss */
-            obfree(otmp, (struct obj *) 0);
+                             (u.umortality > oldumort) ? 0 : 10, TRUE);
+                obfree(otmp, (struct obj *) 0);
+            }
         } else {
             place_object(otmp, u.ux, u.uy);
             if (!Blind)
@@ -1802,7 +1805,7 @@ int style;
             if (multi)
                 nomul(0);
             if (thitu(9 + singleobj->spe, dmgval(singleobj, &youmonst),
-                      singleobj, (char *) 0))
+                      &singleobj, (char *) 0))
                 stop_occupation();
         }
         if (style == ROLL) {

src/uhitm.c

@@ -731,7 +731,8 @@ int thrown; /* HMON_xxx (0 => hand-to-hand, other => ranged) */
             else
                 setuwep((struct obj *) 0);
             freeinv(obj);
-            potionhit(mon, obj, TRUE);
+            potionhit(mon, obj,
+                      hand_to_hand ? POTHIT_HERO_BASH : POTHIT_HERO_THROW);
             if (mon->mhp <= 0)
                 return FALSE; /* killed */
             hittxt = TRUE;

src/zap.c

@@ -3429,7 +3429,7 @@ int dx, dy;
         if (bhitpos.x == u.ux && bhitpos.y == u.uy) { /* ct == 9 */
             if (Fumbling || rn2(20) >= ACURR(A_DEX)) {
                 /* we hit ourselves */
-                (void) thitu(10 + obj->spe, dmgval(obj, &youmonst), obj,
+                (void) thitu(10 + obj->spe, dmgval(obj, &youmonst), &obj,
                              "boomerang");
                 endmultishot(TRUE);
                 break;