Fix: passive AD_MAGM damage when attacking the Oracle (player or another monster).

This is a long-standing bug, especially concerning pets or other
monsters attacking the Oracle. The order of events were wrong - the
attacking pet/monster would take passive AD_MAGM (magic missile) first,
and then the actual attack would occur. This was because 'mhit' was not
defined for that type of passive attack. Oops. It was really that
simple. While there, I noticed that monsters that fall under
resists_mgc() were not accounted for, so that'd been included.

While working on this, I noticed that the same conditions for the player
attacking the Oracle could use some attention also.

Author: k21971

doc/evilhack-changelog.md

@@ -3537,4 +3537,6 @@ The following changes to date are:
 - Tweak power cost for wizards casting force bolt spell
 - Adjust feedback when hitting a water-based monster or one that is
   underwater with burning hands spell
+- Fix: passive AD_MAGM damage when attacking the Oracle (player or
+  another monster)
 

src/mhitm.c

@@ -3294,22 +3294,33 @@ struct obj *mwep;
         break;
     /* Grudge patch. */
     case AD_MAGM:
-      /* wrath of gods for attacking Oracle */
-        if (resists_magm(magr) || defended(magr, AD_MAGM)) {
-            tmp = (tmp + 1) / 2;
-            if (canseemon(magr)) {
-                shieldeff(magr->mx, magr->my);
-                pline(magr->data == &mons[PM_WOODCHUCK] ? "ZOT!" :
-                      "%s is hit by magic missiles appearing from thin air!",
-                      Monnam(magr));
-                pline("Some missiles bounce off!");
+        /* wrath of gods for attacking Oracle */
+        if (mhit) {
+            if (resists_mgc(magr->data)) {
+                tmp = 0;
+                if (canseemon(magr)) {
+                    shieldeff(magr->mx, magr->my);
+                    pline("%s is hit by magic missiles appearing from thin air!",
+                          Monnam(magr));
+                    pline_The("missiles bounce off!");
+                }
+            } else if (resists_magm(magr) || defended(magr, AD_MAGM)) {
+                tmp = (tmp + 1) / 2;
+                if (canseemon(magr)) {
+                    shieldeff(magr->mx, magr->my);
+                    pline(magr->data == &mons[PM_WOODCHUCK] ? "ZOT!" :
+                          "%s is hit by magic missiles appearing from thin air!",
+                          Monnam(magr));
+                    pline("Some missiles bounce off!");
+                }
+                goto assess_dmg;
+            } else {
+                if (canseemon(magr))
+                    pline(magr->data == &mons[PM_WOODCHUCK] ? "ZOT!" :
+                          "%s is hit by magic missiles appearing from thin air!",
+                          Monnam(magr));
+                goto assess_dmg;
             }
-        } else {
-            if (canseemon(magr))
-                pline(magr->data == &mons[PM_WOODCHUCK] ? "ZOT!" :
-                      "%s is hit by magic missiles appearing from thin air!",
-                      Monnam(magr));
-            goto assess_dmg;
         }
         break;
     case AD_ENCH: /* KMH -- remove enchantment (disenchanter) */

src/uhitm.c

@@ -2685,6 +2685,11 @@ struct attack *mattk;
         other += 10;
     if (Confusion || Stunned) /* hard to do much anything if impaired */
         other += 20;
+    if (mdef->data == &mons[PM_ORACLE]) {
+        /* stealing from the Oracle will never succeed,
+           although the attempt is allowed [see AD_MAGM in passive()] */
+        other += 50;
+    }
 
     /* failure routine */
     if (!Upolyd
@@ -4676,19 +4681,25 @@ boolean wep_was_destroyed;
         break;
     case AD_MAGM:
         /* wrath of gods for attacking Oracle */
-        if (Antimagic) {
+        if (!uwep && thievery && mon->mpeaceful) {
+            pline_The("gods notice your deception!");
+            /* The Oracle notices too... */
+            setmangry(mon, FALSE);
+        }
+        You("are hit by magic missiles appearing from thin air!");
+
+        if (resists_mgc(youmonst.data)) { /* no damage */
+            shieldeff(u.ux, u.uy);
+            pline_The("missiles bounce off!");
+            monstseesu(M_SEEN_MAGR);
+            tmp = 0;
+        } else if (Antimagic) { /* half damage */
             shieldeff(u.ux, u.uy);
-            You("are hit by magic missiles appearing from thin air!");
             pline("Some missiles bounce off!");
             monstseesu(M_SEEN_MAGR);
             tmp = (tmp + 1) / 2;
             mdamageu(mon, tmp);
-        } else {
-            if (!uwep && thievery && mon->mpeaceful)
-                pline_The("gods notice your deception!");
-            /* The Oracle notices too... */
-            setmangry(mon, FALSE);
-            You("are hit by magic missiles appearing from thin air!");
+        } else { /* full damage */
             mdamageu(mon, tmp);
         }
         break;