From b44a547153bb358570d2b124150bc6840dae0bdd Mon Sep 17 00:00:00 2001
From: PatR <rankin@nethack.org>
Date: Mon, 3 Feb 2025 23:20:07 -0800
Subject: [PATCH] fix resistance breakage

The Mitre of Holiness commit broke resistance handling.  This seems
to work correctly.
---
 include/monst.h | 16 ++++++++--------
 src/mondata.c   | 29 ++++++++++++++---------------
 2 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/include/monst.h b/include/monst.h
index b3f8956fd..9315d31f0 100644
--- a/include/monst.h
+++ b/include/monst.h
@@ -268,14 +268,14 @@ struct monst {
 #endif
 #define mon_resistancebits(mon) \
     ((mon)->data->mresists | (mon)->mextrinsics | (mon)->mintrinsics)
-#define resists_fire(mon)   Resists_Elem(mon, MR_FIRE)
-#define resists_cold(mon)   Resists_Elem(mon, MR_COLD)
-#define resists_sleep(mon)  Resists_Elem(mon, MR_SLEEP)
-#define resists_disint(mon) Resists_Elem(mon, MR_DISINT)
-#define resists_elec(mon)   Resists_Elem(mon, MR_ELEC)
-#define resists_poison(mon) Resists_Elem(mon, MR_POISON)
-#define resists_acid(mon)   Resists_Elem(mon, MR_ACID)
-#define resists_ston(mon)   Resists_Elem(mon, MR_STONE)
+#define resists_fire(mon)   Resists_Elem(mon, FIRE_RES)
+#define resists_cold(mon)   Resists_Elem(mon, COLD_RES)
+#define resists_sleep(mon)  Resists_Elem(mon, SLEEP_RES)
+#define resists_disint(mon) Resists_Elem(mon, DISINT_RES)
+#define resists_elec(mon)   Resists_Elem(mon, SHOCK_RES)
+#define resists_poison(mon) Resists_Elem(mon, POISON_RES)
+#define resists_acid(mon)   Resists_Elem(mon, ACID_RES)
+#define resists_ston(mon)   Resists_Elem(mon, STONE_RES)
 
 #define is_lminion(mon) \
     (is_minion((mon)->data) && mon_aligntyp(mon) == A_LAWFUL)
diff --git a/src/mondata.c b/src/mondata.c
index bb032bdfd..ef8f6fbc5 100644
--- a/src/mondata.c
+++ b/src/mondata.c
@@ -126,24 +126,24 @@ defended(struct monst *mon, int adtyp)
 /* returns True if monster resists particular elemental damage; mostly used
    in order to check effects of carried artifacts */
 boolean
-Resists_Elem(struct monst *mon, int restyp)
+Resists_Elem(struct monst *mon, int proptyp)
 {
     struct obj *o;
     long slotmask;
     boolean is_you = (mon == &gy.youmonst);
-    int u_resist, dmgtyp = 0, proptyp = 0;
+    int u_resist = 0, dmgtyp = 0, restyp = 0;
 
-    switch (restyp) {
-    case MR_FIRE:
-    case MR_COLD:
-    case MR_SLEEP:
-    case MR_DISINT:
-    case MR_ELEC:
-    case MR_POISON:
-    case MR_ACID:
-    case MR_STONE:
-        dmgtyp = restyp;
-        proptyp = dmgtyp - 1; /* valid for dmgtyp|restyp 2..9 */
+    switch (proptyp) {
+    case FIRE_RES:
+    case COLD_RES:
+    case SLEEP_RES:
+    case DISINT_RES:
+    case SHOCK_RES:
+    case POISON_RES:
+    case ACID_RES:
+    case STONE_RES:
+        dmgtyp = restyp = proptyp + 1; /* valid for dmgtyp|restyp 2..9 */
+        u_resist = u.uprops[proptyp].intrinsic || u.uprops[proptyp].extrinsic;
         break;
 
     /* accept these, but we expect callers to use their routines directly */
@@ -155,10 +155,9 @@ Resists_Elem(struct monst *mon, int restyp)
         return resists_blnd(mon);
 
     default:
-        impossible("Resists_Elem(%d), unexpected resistance type", restyp);
+        impossible("Resists_Elem(%d), unexpected property type", proptyp);
         return FALSE;
     }
-    u_resist = u.uprops[restyp].intrinsic || u.uprops[restyp].extrinsic;
 
     if (is_you ? u_resist : ((mon_resistancebits(mon) & restyp) != 0))
         return TRUE;