fix #Q404 - monster wielding cursed corpse

From a bug report, applying a bullwhip
towards a monster to try to steal its weapon would report that a cursed
cockatrice corpse was welded to the monster's hands even though corpses
wielded by the player never become welded.  Code for monsters deciding
what to wield knew that corpses don't weld; everywhere else seems to
assume that they only wield weldable weapons.  Add a routine to check
whether a wielded item is welded, similar to what's done for the hero.  I
fixed a couple of other spots besides use_whip() but didn't hunt all over.

doc/fixes34.4

@@ -315,6 +315,7 @@ shapechangers who take on mimic or hider form will mimic or hide when feasible
 avoid War message if tinning a Rider corpse fails
 prevent long messages from triggering access violation or segmentation fault
 	due to buffer overflow in pline()
+cursed corpse wielded by a monster isn't welded to its hand or paw
 
 
 Platform- and/or Interface-Specific Fixes

include/extern.h

@@ -2510,6 +2510,7 @@ E int FDECL(chwepon, (struct obj *,int));
 E int FDECL(welded, (struct obj *));
 E void FDECL(weldmsg, (struct obj *));
 E void FDECL(setmnotwielded, (struct monst *,struct obj *));
+E boolean FDECL(mwelded, (struct obj *));
 
 /* ### windows.c ### */
 

src/apply.c

@@ -2397,7 +2397,7 @@ struct obj *obj;
 		mon_hand = 0;	/* lint suppression */
 
 	    You("wrap your bullwhip around %s.", yname(otmp));
-	    if (gotit && otmp->cursed) {
+	    if (gotit && mwelded(otmp)) {
 		pline("%s welded to %s %s%c",
 		      (otmp->quan == 1L) ? "It is" : "They are",
 		      mhis(mtmp), mon_hand,

src/muse.c

@@ -2210,19 +2210,21 @@ mcould_eat_tin(mon)
 struct monst *mon;
 {
 	struct obj *obj, *mwep;
+	boolean welded_wep;
 
 	/* monkeys who manage to steal tins can't open and eat them
 	   even if they happen to also have the appropriate tool */
 	if (is_animal(mon->data)) return FALSE;
 
 	mwep = MON_WEP(mon);
+	welded_wep = mwep && mwelded(mwep);
 	/* this is different from the player; tin opener or dagger doesn't
 	   have to be wielded, and knife can be used instead of dagger
 	   (even so, non-nymphs don't pick up tins, so only nymphs might
 	   end up being able to benefit from them) */
 	for (obj = mon->minvent; obj; obj = obj->nobj) {
 	    /* if stuck with a cursed weapon, don't check rest of inventory */
-	    if (mwep && mwep->cursed && obj != mwep) continue;
+	    if (welded_wep && obj != mwep) continue;
 
 	    if (obj->otyp == TIN_OPENER ||
 		(obj->oclass == WEAPON_CLASS &&

src/weapon.c

@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)weapon.c	3.5	2006/12/14	*/
+/*	SCCS Id: @(#)weapon.c	3.5	2007/02/09	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -458,7 +458,7 @@ register struct monst *mtmp;
 		case P_CROSSBOW:
 		  propellor = (oselect(mtmp, CROSSBOW));
 		}
-		if ((otmp = MON_WEP(mtmp)) && otmp->cursed && otmp != propellor
+		if ((otmp = MON_WEP(mtmp)) && mwelded(otmp) && otmp != propellor
 				&& mtmp->weapon_check == NO_WEAPON_WANTED)
 			propellor = 0;
 	    }
@@ -474,7 +474,7 @@ register struct monst *mtmp;
 		if (rwep[i] != LOADSTONE) {
 			/* Don't throw a cursed weapon-in-hand or an artifact */
 			if ((otmp = oselect(mtmp, rwep[i])) && !otmp->oartifact
-			    && (!otmp->cursed || otmp != MON_WEP(mtmp)))
+			    && !(otmp == MON_WEP(mtmp) && mwelded(otmp)))
 				return(otmp);
 		} else for(otmp=mtmp->minvent; otmp; otmp=otmp->nobj) {
 		    if (otmp->otyp == LOADSTONE && !otmp->cursed)
@@ -592,7 +592,7 @@ boolean polyspot;
 	 * polymorphed into little monster.  But it's not quite clear how to
 	 * handle this anyway....
 	 */
-	if (!(mw_tmp->cursed && mon->weapon_check == NO_WEAPON_WANTED))
+	if (!(mwelded(mw_tmp) && mon->weapon_check == NO_WEAPON_WANTED))
 	    mon->weapon_check = NEED_WEAPON;
 	return;
 }
@@ -653,7 +653,7 @@ register struct monst *mon;
 		 * can know it's cursed and needn't even bother trying.
 		 * Still....
 		 */
-		if (mw_tmp && mw_tmp->cursed && mw_tmp->otyp != CORPSE) {
+		if (mw_tmp && mwelded(mw_tmp)) {
 		    if (canseemon(mon)) {
 			char welded_buf[BUFSZ];
 			const char *mon_hand = mbodypart(mon, HAND);
@@ -684,7 +684,7 @@ register struct monst *mon;
 		mon->weapon_check = NEED_WEAPON;
 		if (canseemon(mon)) {
 		    pline("%s wields %s!", Monnam(mon), doname(obj));
-		    if (obj->cursed && obj->otyp != CORPSE) {
+		    if (mwelded(mw_tmp)) {
 			pline("%s %s to %s %s!",
 			    Tobjnam(obj, "weld"),
 			    is_plural(obj) ? "themselves" : "itself",

src/wield.c

@@ -855,4 +855,14 @@ register struct obj *obj;
 	obj->owornmask = savewornmask;
 }
 
+/* test whether monster's wielded weapon is stuck to hand/paw/whatever */
+boolean
+mwelded(obj)
+struct obj *obj;
+{
+    /* caller is responsible for making sure this is a monster's item */
+    if (obj && (obj->owornmask & W_WEP) && will_weld(obj)) return TRUE;
+    return FALSE;
+}
+
 /*wield.c*/