Fix: lit magic lamps were extinguished by water on dry land.

A magic lamp's flame is meant to be impervious to water and
engulfing, but snuff_lit() granted the exemption by location -
is_damp_terrain() at the lamp's spot, or the hero being swallowed -
rather than by cause. Any water event on dry land therefore snuffed
the lamp: the water-bucket door trap (player-reported, hero and
monster carriers), a rust trap's gush hitting a wielded lamp, water
blasts wetting weapons, and a lamp dropped or thrown into water (in
transit the object is OBJ_FREE, so get_obj_location() reports (0,0),
which reads as dry land). The heuristic also leaked the other way:
stowing a lit magic lamp into a container while swallowed left it
burning inside the container, and magical darkness could not douse a
magic lamp while the hero stood on damp terrain.

Replace the heuristic with a caller-supplied cause flag: snuff_lit()
gains a forced parameter, and a lit magic lamp only goes out when it
is TRUE. Water and engulf callers pass FALSE, so an engulfed
monster's magic lamp now also stays lit, matching the hero's.

* include/extern.h: add the boolean parameter to the prototype.

* src/apply.c: snuff_lit() checks forced instead of terrain/uswallow.

* src/trap.c: water_damage() and both rust-trap gush loops pass
  FALSE; drop the loops' magic-lamp exclusions, now redundant since
  the call is a silent no-op for magic lamps.

* src/pickup.c: container insertion passes TRUE (put-in must always
  snuff).

* src/read.c: darkness passes TRUE (magic douses regardless of
  terrain).

* src/mhitu.c, src/mhitm.c, src/uhitm.c: engulf sites pass FALSE.

Author: k21971

doc/evilhack-changelog.md

@@ -5558,4 +5558,5 @@ The following changes to date are:
 - Monster lookup now reports many more species attributes
 - Object lookup now reports rarity, materials, and more
 - Artifact lookup: fix missing aasimar, add prices and special details
+- Fix: lit magic lamps were extinguished by water on dry land
 

include/extern.h

@@ -48,7 +48,7 @@ E void FDECL(check_leash, (XCHAR_P, XCHAR_P));
 E boolean FDECL(um_dist, (XCHAR_P, XCHAR_P, XCHAR_P));
 E boolean FDECL(snuff_candle, (struct obj *));
 E boolean FDECL(check_mon_jump, (struct monst *, int, int));
-E boolean FDECL(snuff_lit, (struct obj *));
+E boolean FDECL(snuff_lit, (struct obj *, BOOLEAN_P));
 E boolean FDECL(catch_lit, (struct obj *));
 E void FDECL(use_unicorn_horn, (struct obj *));
 E void FDECL(use_figurine, (struct obj **));

src/apply.c

@@ -1477,30 +1477,29 @@ struct obj *otmp;
 
 /* called when lit lamp is hit by water or put into a container or
    you've been swallowed by a monster; obj might be in transit while
-   being thrown or dropped so don't assume that its location is valid */
+   being thrown or dropped so don't assume that its location is valid.
+   A magic lamp's flame is impervious to water and engulfing; callers
+   that must snuff one anyway (stowing it in a container, dousing it
+   via magic) pass forced as TRUE */
 boolean
-snuff_lit(obj)
+snuff_lit(obj, forced)
 struct obj *obj;
+boolean forced; /* TRUE: snuff even a magic lamp */
 {
     xchar x, y;
 
     if (obj->lamplit) {
         if (obj->otyp == OIL_LAMP || obj->otyp == LANTERN
             || obj->otyp == POT_OIL || obj->otyp == MAGIC_LAMP) {
-            (void) get_obj_location(obj, &x, &y, 0);
-
-            if (obj->otyp == MAGIC_LAMP
-                && (is_damp_terrain(x, y) || u.uswallow)) {
+            if (obj->otyp == MAGIC_LAMP && !forced)
                 return FALSE;
-            } else {
-                /* Print message only if player can perceive it */
-                if (obj->where == OBJ_MINVENT ? cansee(x, y) : !Blind) {
-                    pline("%s %s out!", Yname2(obj), otense(obj, "go"));
-                }
-                /* Always extinguish, regardless of visibility */
-                end_burn(obj, TRUE);
-                return TRUE;
-            }
+            (void) get_obj_location(obj, &x, &y, 0);
+            /* Print message only if player can perceive it */
+            if (obj->where == OBJ_MINVENT ? cansee(x, y) : !Blind)
+                pline("%s %s out!", Yname2(obj), otense(obj, "go"));
+            /* Always extinguish, regardless of visibility */
+            end_burn(obj, TRUE);
+            return TRUE;
         }
         if (snuff_candle(obj))
             return TRUE;

src/mhitm.c

@@ -1180,7 +1180,7 @@ struct attack *mattk;
         pline("%s %s.", buf, mon_nam(mdef));
     }
     for (obj = mdef->minvent; obj; obj = obj->nobj)
-        (void) snuff_lit(obj);
+        (void) snuff_lit(obj, FALSE);
 
     if (is_vampshifter(mdef)
         && newcham(mdef, &mons[mdef->cham], FALSE, FALSE)) {

src/mhitu.c

@@ -3207,7 +3207,7 @@ struct attack *mattk;
         swallowed(1);
         for (otmp2 = invent; otmp2; otmp2 = nextobj) {
             nextobj = otmp2->nobj;
-            (void) snuff_lit(otmp2);
+            (void) snuff_lit(otmp2, FALSE);
         }
     }
 

src/pickup.c

@@ -2664,7 +2664,7 @@ struct obj *obj;
     freeinv(obj);
 
     if (obj_is_burning(obj)) /* this used to be part of freeinv() */
-        (void) snuff_lit(obj);
+        (void) snuff_lit(obj, TRUE);
 
     if (floor_container && costly_spot(u.ux, u.uy)) {
         /* defer gold until after put-in message */
@@ -3785,7 +3785,7 @@ boolean creation;
             (void) stop_timer(FIG_TRANSFORM, (genericptr_t) obj);
 
         if (obj_is_burning(obj))
-            (void) snuff_lit(obj);
+            (void) snuff_lit(obj, TRUE);
 
         if (bag->otyp == ICE_BOX && !age_is_relative(obj)) {
             obj->age = monstermoves - obj->age;

src/read.c

@@ -2654,7 +2654,7 @@ xchar x, y;      /* coordinates for centering do_clear_area() */
                         continue;
                     } else {
                         if (!artifact_light(otmp))
-                            (void) snuff_lit(otmp);
+                            (void) snuff_lit(otmp, TRUE);
                         else if (!mon)
                             /* wielded Sunsword or worn shield of light/gold dragon
                             scales; maybe lower its BUC state if not already
@@ -2708,7 +2708,7 @@ xchar x, y;      /* coordinates for centering do_clear_area() */
 
                 if (otmp->lamplit && !mon) {
                     if (!artifact_light(otmp) && lamp) {
-                        (void) snuff_lit(otmp);
+                        (void) snuff_lit(otmp, TRUE);
                     } else {
                         /* wielded Sunsword or worn shield of light/gold dragon
                            scales; maybe raise its BUC state if not already

src/trap.c

@@ -1451,9 +1451,8 @@ unsigned trflags;
             for (otmp = invent; otmp; otmp = nextobj) {
                 nextobj = otmp->nobj;
                 if (otmp->lamplit && otmp != uwep
-                    && otmp->otyp != MAGIC_LAMP
                     && (otmp != uswapwep || !u.twoweap))
-                    (void) snuff_lit(otmp);
+                    (void) snuff_lit(otmp, FALSE);
             }
             if (uarmc)
                 (void) water_damage(uarmc, cloak_simple_name(uarmc),
@@ -2883,9 +2882,9 @@ struct monst *mtmp;
                     pline("%s %s!", A_gush_of_water_hits, mon_nam(mtmp));
                 for (otmp = mtmp->minvent; otmp; otmp = nextobj) {
                     nextobj = otmp->nobj;
-                    if (otmp->lamplit && otmp->otyp != MAGIC_LAMP
+                    if (otmp->lamplit
                         && (otmp->owornmask & (W_WEP | W_SWAPWEP)) == 0)
-                        (void) snuff_lit(otmp);
+                        (void) snuff_lit(otmp, FALSE);
                 }
                 if ((target = which_armor(mtmp, W_ARMC)) != 0)
                     (void) water_damage(target, cloak_simple_name(target),
@@ -4473,7 +4472,7 @@ xchar x, y;
     if (!obj)
         return ER_NOTHING;
 
-    if (snuff_lit(obj))
+    if (snuff_lit(obj, FALSE))
         return ER_DAMAGED;
 
     if (!ostr)

src/uhitm.c

@@ -4064,7 +4064,7 @@ struct attack *mattk;
 
     if (u.uhunger < 1500 && !u.uswallow) {
         for (otmp = mdef->minvent; otmp; otmp = otmp->nobj)
-            (void) snuff_lit(otmp);
+            (void) snuff_lit(otmp, FALSE);
 
         /* force vampire in bat, cloud, or wolf form to revert back to
            vampire form now instead of dealing with that when it dies */