fix #H5853 - carrots don't cure blind pets

Report was for a blinded horse which ate a carrot but remained blind.
This fixes that, and also lets blinded carnivorous pets eat carrots.
Gelatinous cubes now handle carrots too, but since they lack eyses
there won't be any noticeable effect for them.

include/extern.h

@@ -1,4 +1,4 @@
-/* NetHack 3.6	extern.h	$NHDT-Date: 1501725402 2017/08/03 01:56:42 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.598 $ */
+/* NetHack 3.6	extern.h	$NHDT-Date: 1502753404 2017/08/14 23:30:04 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.600 $ */
 /* Copyright (c) Steve Creps, 1988.				  */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -1563,6 +1563,7 @@ E int FDECL(rnd_misc_item, (struct monst *));
 E boolean FDECL(searches_for_item, (struct monst *, struct obj *));
 E boolean FDECL(mon_reflects, (struct monst *, const char *));
 E boolean FDECL(ureflects, (const char *, const char *));
+E void FDECL(mcureblindness, (struct monst *, BOOLEAN_P));
 E boolean FDECL(munstone, (struct monst *, BOOLEAN_P));
 E boolean FDECL(munslime, (struct monst *, BOOLEAN_P));
 

src/dog.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	dog.c	$NHDT-Date: 1446808440 2015/11/06 11:14:00 $  $NHDT-Branch: master $:$NHDT-Revision: 1.52 $ */
+/* NetHack 3.6	dog.c	$NHDT-Date: 1502753406 2017/08/14 23:30:06 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.60 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -736,7 +736,8 @@ struct monst *mon;
 register struct obj *obj;
 {
     struct permonst *mptr = mon->data, *fptr = 0;
-    boolean carni = carnivorous(mptr), herbi = herbivorous(mptr), starving;
+    boolean carni = carnivorous(mptr), herbi = herbivorous(mptr),
+            starving, mblind;
 
     if (is_quest_artifact(obj) || obj_resists(obj, 0, 95))
         return obj->cursed ? TABU : APPORT;
@@ -755,8 +756,10 @@ register struct obj *obj;
             return obj->cursed ? UNDEF : APPORT;
 
         /* a starving pet will eat almost anything */
-        starving =
+        starving = (mon->mtame && !mon->isminion
-            (mon->mtame && !mon->isminion && EDOG(mon)->mhpmax_penalty);
+                    && EDOG(mon)->mhpmax_penalty);
+        /* even carnivores will eat carrots if they're temporarily blind */
+        mblind = (!mon->mcansee && haseyes(mon->data));
 
         /* ghouls prefer old corpses and unhatchable eggs, yum!
            they'll eat fresh non-veggy corpses and hatchable eggs
@@ -813,8 +816,9 @@ register struct obj *obj;
         case TIN:
             return metallivorous(mptr) ? ACCFOOD : MANFOOD;
         case APPLE:
-        case CARROT:
             return herbi ? DOGFOOD : starving ? ACCFOOD : MANFOOD;
+        case CARROT:
+            return (herbi || mblind) ? DOGFOOD : starving ? ACCFOOD : MANFOOD;
         case BANANA:
             return (mptr->mlet == S_YETI && herbi)
                       ? DOGFOOD /* for monkey and ape (tameable), sasquatch */

src/dogmove.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	dogmove.c	$NHDT-Date: 1463704424 2016/05/20 00:33:44 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.60 $ */
+/* NetHack 3.6	dogmove.c	$NHDT-Date: 1502753407 2017/08/14 23:30:07 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.63 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -209,7 +209,7 @@ int x, y; /* dog's starting location, might be different from current */
 boolean devour;
 {
     register struct edog *edog = EDOG(mtmp);
-    boolean poly, grow, heal, slimer, deadmimic;
+    boolean poly, grow, heal, eyes, slimer, deadmimic;
     int nutrit;
     long oprice;
     char objnambuf[BUFSZ];
@@ -226,6 +226,7 @@ boolean devour;
     poly = polyfodder(obj);
     grow = mlevelgain(obj);
     heal = mhealup(obj);
+    eyes = (obj->otyp == CARROT);
 
     if (devour) {
         if (mtmp->meating > 1)
@@ -343,6 +344,8 @@ boolean devour;
     }
     if (heal)
         mtmp->mhp = mtmp->mhpmax;
+    if ((eyes || heal) && !mtmp->mcansee)
+        mcureblindness(mtmp, canseemon(mtmp));
     if (deadmimic)
         quickmimic(mtmp);
     return 1;

src/mon.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	mon.c	$NHDT-Date: 1496531114 2017/06/03 23:05:14 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.240 $ */
+/* NetHack 3.6	mon.c	$NHDT-Date: 1502753408 2017/08/14 23:30:08 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.242 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -886,9 +886,9 @@ int
 meatobj(mtmp) /* for gelatinous cubes */
 struct monst *mtmp;
 {
-    register struct obj *otmp, *otmp2;
+    struct obj *otmp, *otmp2;
     struct permonst *ptr, *original_ptr = mtmp->data;
-    int poly, grow, heal, count = 0, ecount = 0;
+    int poly, grow, heal, eyes, count = 0, ecount = 0;
     char buf[BUFSZ];
 
     buf[0] = '\0';
@@ -986,6 +986,7 @@ struct monst *mtmp;
             poly = polyfodder(otmp);
             grow = mlevelgain(otmp);
             heal = mhealup(otmp);
+            eyes = (otmp->otyp == CARROT);
             delobj(otmp); /* munch */
             ptr = mtmp->data;
             if (poly) {
@@ -996,6 +997,8 @@ struct monst *mtmp;
             } else if (heal) {
                 mtmp->mhp = mtmp->mhpmax;
             }
+            if ((eyes || heal) && !mtmp->mcansee)
+                mcureblindness(mtmp, canseemon(mtmp));
             /* in case it polymorphed or died */
             if (ptr != original_ptr)
                 return !ptr ? 2 : 1;

src/muse.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	muse.c	$NHDT-Date: 1469840918 2016/07/30 01:08:38 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.78 $ */
+/* NetHack 3.6	muse.c	$NHDT-Date: 1502753408 2017/08/14 23:30:08 $  $NHDT-Branch: NetHack-3.6.0 $:$NHDT-Revision: 1.79 $ */
 /*      Copyright (C) 1990 by Ken Arromdee                         */
 /* NetHack may be freely redistributed.  See license for details.  */
 
@@ -603,7 +603,7 @@ struct monst *mtmp;
     int i, fleetim, how = 0;
     struct obj *otmp = m.defensive;
     boolean vis, vismon, oseen;
-    const char *Mnam, *mcsa = "%s can see again.";
+    const char *Mnam;
 
     if ((i = precheck(mtmp, otmp)) != 0)
         return i;
@@ -628,10 +628,7 @@ struct monst *mtmp;
                 pline_The("tip of %s's horn glows!", mon_nam(mtmp));
         }
         if (!mtmp->mcansee) {
-            mtmp->mcansee = 1;
+            mcureblindness(mtmp, vismon);
-            mtmp->mblinded = 0;
-            if (vismon)
-                pline(mcsa, Monnam(mtmp));
         } else if (mtmp->mconf || mtmp->mstun) {
             mtmp->mconf = mtmp->mstun = 0;
             if (vismon)
@@ -939,12 +936,8 @@ struct monst *mtmp;
         mtmp->mhp += i;
         if (mtmp->mhp > mtmp->mhpmax)
             mtmp->mhp = ++mtmp->mhpmax;
-        if (!otmp->cursed && !mtmp->mcansee) {
+        if (!otmp->cursed && !mtmp->mcansee)
-            mtmp->mcansee = 1;
+            mcureblindness(mtmp, vismon);
-            mtmp->mblinded = 0;
-            if (vismon)
-                pline(mcsa, Monnam(mtmp));
-        }
         if (vismon)
             pline("%s looks better.", Monnam(mtmp));
         if (oseen)
@@ -957,12 +950,8 @@ struct monst *mtmp;
         mtmp->mhp += i;
         if (mtmp->mhp > mtmp->mhpmax)
             mtmp->mhp = (mtmp->mhpmax += (otmp->blessed ? 5 : 2));
-        if (!mtmp->mcansee) {
+        if (!mtmp->mcansee)
-            mtmp->mcansee = 1;
+            mcureblindness(mtmp, vismon);
-            mtmp->mblinded = 0;
-            if (vismon)
-                pline(mcsa, Monnam(mtmp));
-        }
         if (vismon)
             pline("%s looks much better.", Monnam(mtmp));
         if (oseen)
@@ -974,12 +963,8 @@ struct monst *mtmp;
         if (otmp->otyp == POT_SICKNESS)
             unbless(otmp); /* Pestilence */
         mtmp->mhp = (mtmp->mhpmax += (otmp->blessed ? 8 : 4));
-        if (!mtmp->mcansee && otmp->otyp != POT_SICKNESS) {
+        if (!mtmp->mcansee && otmp->otyp != POT_SICKNESS)
-            mtmp->mcansee = 1;
+            mcureblindness(mtmp, vismon);
-            mtmp->mblinded = 0;
-            if (vismon)
-                pline(mcsa, Monnam(mtmp));
-        }
         if (vismon)
             pline("%s looks completely healed.", Monnam(mtmp));
         if (oseen)
@@ -2175,6 +2160,20 @@ const char *fmt, *str;
     return FALSE;
 }
 
+/* cure mon's blindness (use_defensive, dog_eat, meatobj) */
+void
+mcureblindness(mon, verbos)
+struct monst *mon;
+boolean verbos;
+{
+    if (!mon->mcansee) {
+        mon->mcansee = 1;
+        mon->mblinded = 0;
+        if (verbos && haseyes(mon->data))
+            pline("%s can see again.", Monnam(mon));
+    }
+}
+
 /* TRUE if the monster ate something */
 boolean
 munstone(mon, by_you)