hats vs horns

Some recent newsgroup discussion claiming that a pet ki-rin was
wearing a helmet (I think poster was hallucinating) caused me to look
at some of the hat handling code.  There were a couple of noticeable
problems and one latent one in code added for 3.4.1.  Polymorphing
into a minotaur pushes hard helmets off hero's head, but nothing
prevented you from putting one right back on.  Helmet wearing monsters
who polymorphed into minotaurs weren't affected at all.  And message
handling always assumed multiple horns even though we have some singled
horned monsters, but since all those have no hands they can't wear any
armor and that potential pluralization issue wasn't noticeable.

include/extern.h

@@ -1154,6 +1154,7 @@ E boolean FDECL(can_track, (struct permonst *));
 E boolean FDECL(breakarm, (struct permonst *));
 E boolean FDECL(sliparm, (struct permonst *));
 E boolean FDECL(sticks, (struct permonst *));
+E int FDECL(num_horns, (struct permonst *));
 /* E boolean FDECL(canseemon, (struct monst *)); */
 E struct attack *FDECL(dmgtype_fromattack, (struct permonst *,int,int));
 E boolean FDECL(dmgtype, (struct permonst *,int));

include/mondata.h

@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)mondata.h	3.4	2001/02/14	*/
+/*	SCCS Id: @(#)mondata.h	3.4	2003/01/08	*/
 /* Copyright (c) 1989 Mike Threepoint				  */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -45,7 +45,7 @@
 #define nolimbs(ptr)		(((ptr)->mflags1 & M1_NOLIMBS) == M1_NOLIMBS)
 #define notake(ptr)		(((ptr)->mflags1 & M1_NOTAKE) != 0L)
 #define has_head(ptr)		(((ptr)->mflags1 & M1_NOHEAD) == 0L)
-#define has_horns(ptr)		((ptr) == &mons[PM_MINOTAUR])
+#define has_horns(ptr)		(num_horns(ptr) > 0)
 #define is_whirly(ptr)		((ptr)->mlet == S_VORTEX || \
 				 (ptr) == &mons[PM_AIR_ELEMENTAL])
 #define is_silent(ptr)		((ptr)->msound == MS_SILENT)

src/do_wear.c

@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)do_wear.c	3.4	2002/11/29	*/
+/*	SCCS Id: @(#)do_wear.c	3.4	2003/01/08	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -1202,6 +1202,12 @@ boolean noisy;
 	if (uarmh) {
 	    if (noisy) already_wearing(an(c_helmet));
 	    err++;
+	} else if (Upolyd && has_horns(youmonst.data) && !is_flimsy(otmp)) {
+	    /* (flimsy exception matches polyself handling) */
+	    if (noisy)
+		pline_The("%s won't fit over your horn%s.",
+			  c_helmet, plur(num_horns(youmonst.data)));
+	    err++;
 	} else
 	    *mask = W_ARMH;
     } else if (is_shield(otmp)) {

src/mondata.c

@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)mondata.c	3.4	2002/12/09	*/
+/*	SCCS Id: @(#)mondata.c	3.4	2003/01/08	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -301,6 +301,26 @@ sticks(ptr)	/* creature sticks other creatures it hits */
 		attacktype(ptr,AT_HUGS)));
 }
 
+/* number of horns this type of monster has on its head */
+int
+num_horns(ptr)
+struct permonst *ptr;
+{
+    switch (monsndx(ptr)) {
+    case PM_HORNED_DEVIL:	/* ? "more than one" */
+    case PM_MINOTAUR:
+	return 2;
+    case PM_WHITE_UNICORN:
+    case PM_GRAY_UNICORN:
+    case PM_BLACK_UNICORN:
+    case PM_KI_RIN:
+	return 1;
+    default:
+	break;
+    }
+    return 0;
+}
+
 struct attack *
 dmgtype_fromattack(ptr, dtyp, atyp)
 struct permonst *ptr;
@@ -365,7 +385,7 @@ monsndx(ptr)		/* return an index into the mons array */
 		/* ought to switch this to use `fmt_ptr' */
 	    panic("monsndx - could not index monster (%lx)",
 		  (unsigned long)ptr);
-	    return FALSE;		/* will not get here */
+	    return NON_PM;		/* will not get here */
 	}
 
 	return(i);

src/polyself.c

@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)polyself.c	3.4	2002/07/11	*/
+/*	SCCS Id: @(#)polyself.c	3.4	2003/01/08	*/
 /*	Copyright (C) 1987, 1988, 1989 by Ken Arromdee */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -617,18 +617,20 @@ break_armor()
 #endif
     }
     if (has_horns(youmonst.data)) {
-    	if ((otmp = uarmh) != 0) {
-		if (is_flimsy(otmp) && !donning(otmp)) {
-			char yourbuf[BUFSZ];
-			/* Future possiblities: This could damage/destroy helmet*/
-			Your("horns pierce through %s %s.", shk_your(yourbuf, otmp),
-				xname(otmp));
-		} else {
-	    		if (donning(otmp)) cancel_don();
-			Your("helmet falls to the %s!", surface(u.ux, u.uy));
-			(void) Helmet_off();
-			dropx(otmp);
-		}
+	if ((otmp = uarmh) != 0) {
+	    if (is_flimsy(otmp) && !donning(otmp)) {
+		char hornbuf[BUFSZ], yourbuf[BUFSZ];
+
+		/* Future possiblities: This could damage/destroy helmet */
+		Sprintf(hornbuf, "horn%s", plur(num_horns(youmonst.data)));
+		Your("%s %s through %s %s.", vtense(hornbuf, "pierce"),
+		     shk_your(yourbuf, otmp), xname(otmp));
+	    } else {
+		if (donning(otmp)) cancel_don();
+		Your("helmet falls to the %s!", surface(u.ux, u.uy));
+		(void) Helmet_off();
+		dropx(otmp);
+	    }
 	}
     }
     if (nohands(youmonst.data) || verysmall(youmonst.data)) {

src/worn.c

@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)worn.c	3.4	2002/11/07	*/
+/*	SCCS Id: @(#)worn.c	3.4	2003/01/08	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -436,6 +436,8 @@ boolean racialexception;
 		    break;
 		case W_ARMH:
 		    if (!is_helmet(obj)) continue;
+		    /* (flimsy exception matches polyself handling) */
+		    if (has_horns(mon->data) && !is_flimsy(obj)) continue;
 		    break;
 		case W_ARMS:
 		    if (!is_shield(obj)) continue;
@@ -596,6 +598,7 @@ boolean polyspot;
 	register struct obj *otmp;
 	struct permonst *mdat = mon->data;
 	boolean vis = cansee(mon->mx, mon->my);
+	boolean handless_or_tiny = (nohands(mdat) || verysmall(mdat));
 	const char *pronoun = mhim(mon),
 			*ppronoun = mhis(mon);
 
@@ -675,7 +678,7 @@ boolean polyspot;
 	    }
 #endif
 	}
-	if (nohands(mdat) || verysmall(mdat)) {
+	if (handless_or_tiny) {
 	    /* [caller needs to handle weapon checks] */
 	    if ((otmp = which_armor(mon, W_ARMG)) != 0) {
 		if (vis)
@@ -693,7 +696,11 @@ boolean polyspot;
 		if (polyspot) bypass_obj(otmp);
 		m_lose_armor(mon, otmp);
 	    }
-	    if ((otmp = which_armor(mon, W_ARMH)) != 0) {
+	}
+	if (handless_or_tiny || has_horns(mdat)) {
+	    if ((otmp = which_armor(mon, W_ARMH)) != 0 &&
+		    /* flimsy test for horns matches polyself handling */
+		    (handless_or_tiny || !is_flimsy(otmp))) {
 		if (vis)
 		    pline("%s helmet falls to the %s!",
 			  s_suffix(Monnam(mon)), surface(mon->mx, mon->my));
@@ -703,8 +710,7 @@ boolean polyspot;
 		m_lose_armor(mon, otmp);
 	    }
 	}
-	if (nohands(mdat) || verysmall(mdat) || slithy(mdat) ||
-	    mdat->mlet == S_CENTAUR) {
+	if (handless_or_tiny || slithy(mdat) || mdat->mlet == S_CENTAUR) {
 	    if ((otmp = which_armor(mon, W_ARMF)) != 0) {
 		if (vis) {
 		    if (is_whirly(mon->data))