Accurately track which items have been discovered, even if not #named

This fixes a couple of bugs: a long-standing bug in which writing a
scroll by label could fail even if you've already seen a scroll with
that label (due to the game not tracking whether or not you've seen a
scroll if it doesn't have a name); and a somewhat newer bug in which
spellbooks auto-identified by Wizard knowledge were marked as having
been encountered (rather than as known but not encountered).

Breaks save file compatibility, but not bones files.

doc/fixes3-7-0.txt

@@ -1542,6 +1542,9 @@ on arboreal levels (Ranger quest) where STONE terrain is treated as TREE, an
 an item at an ordinary tree location, whether the level is arboreal or not,
 	would be described as itself with no mention of the tree
 some types of shopkeeper now start with a scroll of charging
+objects are now accurately tracked as discovered even if not type-named nor
+        formally identified (fixing some bugs in scroll writing, and making
+        the discoveries list more accurate)
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository

include/extern.h

@@ -2155,7 +2155,8 @@ extern boolean objdescr_is(struct obj *, const char *) NONNULLARG2;
 extern void oinit(void);
 extern void savenames(NHFILE *) NONNULLARG1;
 extern void restnames(NHFILE *) NONNULLARG1;
-extern void discover_object(int, boolean, boolean);
+extern void observe_object(struct obj *) NONNULLARG1;
+extern void discover_object(int, boolean, boolean, boolean);
 extern void undiscover_object(int);
 extern boolean interesting_to_discover(int);
 extern int choose_disco_sort(int);

include/hack.h

@@ -1527,7 +1527,7 @@ typedef uint32_t mmflags_nht;     /* makemon MM_ flags */
     (objects[(obj)->otyp].a_ac + (obj)->spe                             \
      - min((int) greatest_erosion(obj), objects[(obj)->otyp].a_ac))
 
-#define makeknown(x) discover_object((x), TRUE, TRUE)
+#define makeknown(x) discover_object((x), TRUE, TRUE, TRUE)
 #define distu(xx, yy) dist2((coordxy) (xx), (coordxy) (yy), u.ux, u.uy)
 #define mdistu(mon) distu((mon)->mx, (mon)->my)
 #define onlineu(xx, yy) online2((coordxy)(xx), (coordxy)(yy), u.ux, u.uy)

include/obj.h

@@ -107,7 +107,9 @@ struct obj {
                              * or enchantment); many items have this preset if
                              * they lack anything interesting to discover */
     Bitfield(dknown, 1);    /* description known (item seen "up close");
-                             * some types of items always have dknown set */
+                             * some types of items always have dknown set;
+                             * use observe_object to set to TRUE so that the
+                             * discoveries list is still correct */
     Bitfield(bknown, 1);    /* BUC (blessed/uncursed/cursed) known */
     Bitfield(rknown, 1);    /* rustproofing status known */
     Bitfield(cknown, 1); /* for containers (including statues): the contents

include/objclass.h

@@ -54,8 +54,8 @@ struct objclass {
                                      * otherwise, obj->dknown and obj->bknown
                                      * tell all, and obj->known should always
                                      * be set for proper merging behavior. */
-    Bitfield(oc_pre_discovered, 1); /* already known at start of game; flagged
+    Bitfield(oc_encountered, 1);    /* hero has observed such an item at least
-                                     * as such when discoveries are listed */
+                                       once (perhaps without naming it) */
     Bitfield(oc_magic, 1);          /* inherently magical object */
     Bitfield(oc_charged, 1);        /* may have +n or (n) charges */
     Bitfield(oc_unique, 1);         /* special one-of-a-kind object */

include/patchlevel.h

@@ -17,7 +17,7 @@
  * Incrementing EDITLEVEL can be used to force invalidation of old bones
  * and save files.
  */
-#define EDITLEVEL 130
+#define EDITLEVEL 131
 
 /*
  * Development status possibilities.

src/apply.c

@@ -2683,7 +2683,7 @@ use_stone(struct obj *tstone)
 
     /* in case it was acquired while blinded */
     if (!Blind)
-        tstone->dknown = 1;
+        observe_object(tstone);
     known = (tstone->otyp == TOUCHSTONE && tstone->dknown
               && objects[TOUCHSTONE].oc_name_known);
     Sprintf(stonebuf, "rub on the stone%s", plur(tstone->quan));

src/artifact.c

@@ -1570,7 +1570,7 @@ artifact_hit(
                 }
                 *dmgptr = 2 * mdef->mhp + FATAL_DAMAGE_MODIFIER;
                 pline("%s cuts %s in half!", wepdesc, mon_nam(mdef));
-                otmp->dknown = TRUE;
+                observe_object(otmp);
                 return TRUE;
             } else {
                 if (bigmonst(gy.youmonst.data)) {
@@ -1587,7 +1587,7 @@ artifact_hit(
                  */
                 *dmgptr = 2 * (Upolyd ? u.mh : u.uhp) + FATAL_DAMAGE_MODIFIER;
                 pline("%s cuts you in half!", wepdesc);
-                otmp->dknown = TRUE;
+                observe_object(otmp);
                 return TRUE;
             }
         } else if (is_art(otmp, ART_VORPAL_BLADE)
@@ -1617,7 +1617,7 @@ artifact_hit(
                       mon_nam(mdef));
                 if (Hallucination && !flags.female)
                     pline("Good job Henry, but that wasn't Anne.");
-                otmp->dknown = TRUE;
+                observe_object(otmp);
                 return TRUE;
             } else {
                 if (!has_head(gy.youmonst.data)) {
@@ -1634,7 +1634,7 @@ artifact_hit(
                 }
                 *dmgptr = 2 * (Upolyd ? u.mh : u.uhp) + FATAL_DAMAGE_MODIFIER;
                 pline(ROLL_FROM(behead_msg), wepdesc, "you");
-                otmp->dknown = TRUE;
+                observe_object(otmp);
                 /* Should amulets fall off? */
                 return TRUE;
             }

src/detect.c

@@ -26,7 +26,7 @@ staticfn void reconstrain_map(void);
 staticfn void map_redisplay(void);
 staticfn void browse_map(unsigned, const char *);
 staticfn void map_monst(struct monst *, boolean);
-staticfn void do_dknown_of(struct obj *);
+staticfn void observe_recursively(struct obj *);
 staticfn boolean check_map_spot(coordxy, coordxy, char, unsigned);
 staticfn boolean clear_stale_map(char, unsigned);
 staticfn void sense_trap(struct trap *, coordxy, coordxy, int);
@@ -246,14 +246,14 @@ o_material(struct obj *obj, unsigned material)
 }
 
 staticfn void
-do_dknown_of(struct obj *obj)
+observe_recursively(struct obj *obj)
 {
     struct obj *otmp;
 
-    obj->dknown = 1;
+    observe_object(obj);
     if (Has_contents(obj)) {
         for (otmp = obj->cobj; otmp; otmp = otmp->nobj)
-            do_dknown_of(otmp);
+            observe_recursively(otmp);
     }
 }
 
@@ -638,7 +638,7 @@ object_detect(struct obj *detector, /* object doing the detecting */
 
     if (do_dknown)
         for (obj = gi.invent; obj; obj = obj->nobj)
-            do_dknown_of(obj);
+            observe_recursively(obj);
 
     for (obj = fobj; obj; obj = obj->nobj) {
         if ((!class && !boulder) || o_in(obj, class) || o_in(obj, boulder)) {
@@ -648,7 +648,7 @@ object_detect(struct obj *detector, /* object doing the detecting */
                 ct++;
         }
         if (do_dknown)
-            do_dknown_of(obj);
+            observe_recursively(obj);
     }
 
     for (obj = svl.level.buriedobjlist; obj; obj = obj->nobj) {
@@ -659,7 +659,7 @@ object_detect(struct obj *detector, /* object doing the detecting */
                 ct++;
         }
         if (do_dknown)
-            do_dknown_of(obj);
+            observe_recursively(obj);
     }
 
     if (u.usteed)
@@ -673,7 +673,7 @@ object_detect(struct obj *detector, /* object doing the detecting */
                 || o_in(obj, boulder))
                 ct++;
             if (do_dknown)
-                do_dknown_of(obj);
+                observe_recursively(obj);
         }
         if ((is_cursed && M_AP_TYPE(mtmp) == M_AP_OBJECT
              && (!class || class == objects[mtmp->mappearance].oc_class))
@@ -932,7 +932,7 @@ detect_obj_traps(
         }
         if (Is_box(otmp) && otmp->otrapped) {
             otmp->tknown = 1;
-            otmp->dknown = 1;
+            observe_object(otmp);
             result |= u_at(x, y) ? OTRAP_HERE : OTRAP_THERE;
             if (ft) {
                 flash_glyph_at(x, y, trapglyph, FOUND_FLASH_COUNT);
@@ -1508,7 +1508,7 @@ do_vicinity_map(
                    unlike object detection, we don't notice buried items */
                 otmp = svl.level.objects[zx][zy];
                 if (extended)
-                    otmp->dknown = 1;
+                    observe_object(otmp);
                 map_object(otmp, TRUE);
                 newglyph = glyph_at(zx, zy);
                 /* if otmp is underwater, we'll need to redisplay the water */

src/display.c

@@ -346,7 +346,7 @@ map_object(struct obj *obj, int show)
             neardist = (r * r) * 2 - r; /* same as r*r + r*(r-1) */
 
         if (distu(x, y) <= neardist) {
-            obj->dknown = 1;
+            observe_object(obj);
             glyph = obj_to_glyph(obj, newsym_rn2);
         }
     }
@@ -1585,7 +1585,7 @@ see_nearby_objects(void)
             if (!cansee(ix, iy) || distu(ix, iy) > neardist)
                 continue;
 
-            obj->dknown = 1; /* near enough to see it */
+            observe_object(obj);
             /* operate on remembered glyph rather than current one */
             glyph = levl[ix][iy].glyph;
             if (glyph_is_generic_object(glyph))

src/do_name.c

@@ -669,7 +669,7 @@ docall(struct obj *obj)
             undiscover_object(obj->otyp);
     } else {
         *uname_p = dupstr(buf);
-        discover_object(obj->otyp, FALSE, TRUE); /* possibly add to disco[] */
+        discover_object(obj->otyp, FALSE, TRUE, TRUE); /* possibly add to disco[] */
     }
 }
 

src/do_wear.c

@@ -1196,12 +1196,12 @@ learnring(struct obj *ring, boolean observed)
            mark this ring as having been seen (no need for makeknown);
            otherwise if we have seen this ring, discover its type */
         if (objects[ringtype].oc_name_known)
-            ring->dknown = 1;
+            observe_object(ring);
         else if (ring->dknown)
             makeknown(ringtype);
 #if 0 /* see learnwand() */
         else
-            ring->eknown = 1;
+            observe_object(ring);
 #endif
     }
 

src/eat.c

@@ -1547,7 +1547,8 @@ consume_tin(const char *mesg)
         mnum = tin->corpsenm;
         if (mnum == NON_PM) {
             pline("It turns out to be empty.");
-            tin->dknown = tin->known = 1;
+            observe_object(tin);
+            tin->known = 1;
             tin = costly_tin(COST_OPEN);
             use_up_tin(tin);
             if (always_eat)
@@ -1579,8 +1580,10 @@ consume_tin(const char *mesg)
             if (y_n("Eat it?") == 'n') {
                 if (flags.verbose)
                     You("discard the open tin.");
-                if (!Hallucination)
+                if (!Hallucination) {
-                    tin->dknown = tin->known = 1;
+                    observe_object(tin);
+                    tin->known = 1;
+                }
                 tin = costly_tin(COST_OPEN);
                 use_up_tin(tin);
                 return;
@@ -1594,7 +1597,8 @@ consume_tin(const char *mesg)
 
         eating_conducts(&mons[mnum]);
 
-        tin->dknown = tin->known = 1;
+        observe_object(tin);
+        tin->known = 1;
         /* charge for one at pre-eating cost */
         tin = svc.context.tin.tin = costly_tin(COST_OPEN);
 
@@ -1641,7 +1645,8 @@ consume_tin(const char *mesg)
                   Blind ? "" : " ", Blind ? "" : hcolor(NH_GREEN));
         } else {
             pline("It contains spinach.");
-            tin->dknown = tin->known = 1;
+            observe_object(tin);
+            tin->known = 1;
         }
 
         if (!always_eat && y_n("Eat it?") == 'n') {
@@ -2265,7 +2270,8 @@ eataccessory(struct obj *otmp)
         if (u.uhp <= 0)
             return; /* died from sink fall */
     }
-    otmp->known = otmp->dknown = 1; /* by taste */
+    observe_object(otmp);
+    otmp->known = 1; /* by taste */
     if (!rn2(otmp->oclass == RING_CLASS ? 3 : 5)) {
         switch (otmp->otyp) {
         default:

src/end.c

@@ -921,7 +921,8 @@ artifact_score(
             if (counting) {
                 u.urexp = nowrap_add(u.urexp, points);
             } else {
-                discover_object(otmp->otyp, TRUE, FALSE);
+                discover_object(otmp->otyp, TRUE, TRUE, FALSE);
+                /* not observe_object; dead characters don't observe */
                 otmp->known = otmp->dknown = otmp->bknown = otmp->rknown = 1;
                 /* assumes artifacts don't have quan > 1 */
                 Sprintf(pbuf, "%s%s (worth %ld %s and %ld points)",
@@ -1254,7 +1255,8 @@ really_done(int how)
          */
         for (obj = gi.invent; obj; obj = nextobj) {
             nextobj = obj->nobj;
-            discover_object(obj->otyp, TRUE, FALSE);
+            discover_object(obj->otyp, TRUE, TRUE, FALSE);
+            /* observe_object not necessary after discover_object */
             obj->known = obj->bknown = obj->dknown = obj->rknown = 1;
             set_cknown_lknown(obj); /* set flags when applicable */
             /* we resolve Schroedinger's cat now in case of both
@@ -1496,9 +1498,10 @@ really_done(int how)
                 if (objects[typ].oc_class != GEM_CLASS
                     || typ <= LAST_REAL_GEM) {
                     otmp = mksobj(typ, FALSE, FALSE);
-                    discover_object(otmp->otyp, TRUE, FALSE);
+                    discover_object(otmp->otyp, TRUE, TRUE, FALSE);
-                    otmp->known = 1;  /* for fake amulets */
                     otmp->dknown = 1; /* seen it (blindness fix) */
+                    /* observe_object not necessary after discover_object */
+                    otmp->known = 1;  /* for fake amulets */
                     if (has_oname(otmp))
                         free_oname(otmp);
                     otmp->quan = count;
@@ -1634,9 +1637,9 @@ container_contents(
                                           (boolean (*)(OBJ_P)) 0);
                     for (srtc = sortedcobj; (obj = srtc->obj) != 0; ++srtc) {
                         if (identified) {
-                            discover_object(obj->otyp, TRUE, FALSE);
+                            discover_object(obj->otyp, TRUE, TRUE, FALSE);
-                            obj->known = obj->bknown = obj->dknown
+                            obj->dknown = 1; /* observe_object unnecessary */
-                                = obj->rknown = 1;
+                            obj->known = obj->bknown = obj->rknown = 1;
                             if (Is_container(obj) || obj->otyp == STATUE)
                                 obj->cknown = obj->lknown = 1;
                         }

src/files.c

@@ -2515,7 +2515,7 @@ wizkit_addinv(struct obj *obj)
         return;
 
     /* subset of starting inventory pre-ID */
-    obj->dknown = 1;
+    observe_object(obj);
     if (Role_if(PM_CLERIC))
         obj->bknown = 1; /* ok to bypass set_bknown() */
     /* same criteria as lift_object()'s check for available inventory slot */

src/fountain.c

@@ -641,7 +641,8 @@ drinksink(void)
         otmp->cursed = otmp->blessed = 0;
         pline("Some %s liquid flows from the faucet.",
               Blind ? "odd" : hcolor(OBJ_DESCR(objects[otmp->otyp])));
-        otmp->dknown = !(Blind || Hallucination);
+        if(!(Blind || Hallucination))
+            observe_object(otmp);
         otmp->quan++;       /* Avoid panic upon useup() */
         otmp->fromsink = 1; /* kludge for docall() */
         (void) dopotion(otmp);

src/invent.c

@@ -178,7 +178,7 @@ loot_classify(Loot *sort_item, struct obj *obj)
      * will put lower valued ones before higher valued ones.
      */
     if (!Blind)
-        obj->dknown = 1; /* xname(obj) does this; we want it sooner */
+        observe_object(obj); /* xname(obj) does this; we want it sooner */
     seen = obj->dknown ? TRUE : FALSE,
     /* class order */
     classorder = flags.sortpack ? flags.inv_order : def_srt_order;
@@ -1196,7 +1196,7 @@ hold_another_object(
     char buf[BUFSZ];
 
     if (!Blind)
-        obj->dknown = 1; /* maximize mergeability */
+        observe_object(obj); /* maximize mergeability */
     if (obj->oartifact) {
         /* place_object may change these */
         boolean crysknife = (obj->otyp == CRYSKNIFE);
@@ -2546,7 +2546,8 @@ fully_identify_obj(struct obj *otmp)
     makeknown(otmp->otyp);
     if (otmp->oartifact)
         discover_artifact((xint16) otmp->oartifact);
-    otmp->known = otmp->dknown = otmp->bknown = otmp->rknown = 1;
+    observe_object(otmp);
+    otmp->known = otmp->bknown = otmp->rknown = 1;
     set_cknown_lknown(otmp); /* set otmp->{cknown,lknown} if applicable */
     if (otmp->otyp == EGG && otmp->corpsenm != NON_PM)
         learn_egg_type(otmp->corpsenm);
@@ -6123,7 +6124,7 @@ display_binventory(coordxy x, coordxy y, boolean as_if_seen)
     for (n = 0, obj = svl.level.buriedobjlist; obj; obj = obj->nobj)
         if (obj->ox == x && obj->oy == y) {
             if (as_if_seen)
-                obj->dknown = 1;
+                observe_object(obj);
             n++;
         }
 

src/mhitu.c

@@ -2128,7 +2128,7 @@ doseduce(struct monst *mon)
                 /* have her call your gloves by their correct
                    name, possibly revealing them to you */
                 if (yourgloves)
-                    yourgloves->dknown = 1;
+                    observe_object(yourgloves);
                 verbalize("Well, then you owe me %s%s!",
                           yourgloves ? yname(yourgloves)
                                      : "twelve pairs of gloves",

src/mkobj.c

@@ -834,6 +834,8 @@ static const char dknowns[] = { WAND_CLASS,   RING_CLASS, POTION_CLASS,
 void
 clear_dknown(struct obj *obj)
 {
+    /* note: this is an unobserving not an observing, so don't call
+       observe_object even if dknown is being set to 1 */
     obj->dknown = strchr(dknowns, obj->oclass) ? 0 : 1;
     if ((obj->otyp >= ELVEN_SHIELD && obj->otyp <= ORCISH_SHIELD)
         || obj->otyp == SHIELD_OF_REFLECTION
@@ -960,6 +962,7 @@ mksobj_init(struct obj **obj, boolean artif)
                we initialize glob->owt explicitly so weight() doesn't
                need to perform any fix up and returns glob->owt as-is */
             otmp->owt = objects[otmp->otyp].oc_weight;
+            /* dknown, but not observed */
             otmp->known = otmp->dknown = 1;
             otmp->corpsenm = PM_GRAY_OOZE + (otmp->otyp - GLOB_OF_GRAY_OOZE);
             start_glob_timeout(otmp, 0L);

src/mthrowu.c

@@ -334,7 +334,7 @@ ohitmon(
     ismimic = M_AP_TYPE(mtmp) && M_AP_TYPE(mtmp) != M_AP_MONSTER;
     vis = cansee(gb.bhitpos.x, gb.bhitpos.y);
     if (vis)
-        otmp->dknown = 1;
+        observe_object(otmp);
 
     tmp = 5 + find_mac(mtmp) + omon_adj(mtmp, otmp, FALSE);
     /* High level monsters will be more likely to hit */
@@ -652,7 +652,7 @@ m_throw(
         singleobj->ox = gb.bhitpos.x += dx;
         singleobj->oy = gb.bhitpos.y += dy;
         if (cansee(gb.bhitpos.x, gb.bhitpos.y))
-            singleobj->dknown = 1;
+            observe_object(singleobj);
 
         mtmp = m_at(gb.bhitpos.x, gb.bhitpos.y);
         if (mtmp && shade_miss(mon, mtmp, singleobj, TRUE, TRUE)) {

src/muse.c

@@ -207,7 +207,7 @@ mplayhorn(
                     ? "nearby" : "in the distance");
         unknow_object(otmp); /* hero loses info when unseen obj is used */
     } else if (self) {
-        otmp->dknown = 1;
+        observe_object(otmp);
         objnamp = xname(otmp);
         if (strlen(objnamp) >= QBUFSZ)
             objnamp = simpleonames(otmp);
@@ -216,7 +216,7 @@ mplayhorn(
         pline("%s!", monverbself(mtmp, Monnam(mtmp), "play", objbuf));
         makeknown(otmp->otyp); /* (wands handle this slightly differently) */
     } else {
-        otmp->dknown = 1;
+        observe_object(otmp);
         objnamp = xname(otmp);
         if (strlen(objnamp) >= QBUFSZ)
             objnamp = simpleonames(otmp);
@@ -242,7 +242,7 @@ mreadmsg(struct monst *mtmp, struct obj *otmp)
     if (!vismon && Deaf)
         return; /* no feedback */
 
-    otmp->dknown = 1; /* seeing or hearing scroll read reveals its label */
+    observe_object(otmp); /* seeing/hearing scroll read reveals its label */
     Strcpy(onambuf, singular(otmp, vismon ? doname : ansimpleoname));
 
     if (vismon) {
@@ -291,7 +291,7 @@ staticfn void
 mquaffmsg(struct monst *mtmp, struct obj *otmp)
 {
     if (canseemon(mtmp)) {
-        otmp->dknown = 1;
+        observe_object(otmp);
         pline_mon(mtmp, "%s drinks %s!", Monnam(mtmp), singular(otmp, doname));
     } else if (!Deaf) {
         Soundeffect(se_mon_chugging_potion, 25);
@@ -1967,7 +1967,7 @@ use_offensive(struct monst *mtmp)
          * are not objects.  Also set dknown in mthrowu.c.
          */
         if (cansee(mtmp->mx, mtmp->my)) {
-            otmp->dknown = 1;
+            observe_object(otmp);
             pline_mon(mtmp, "%s hurls %s!",
                       Monnam(mtmp), singular(otmp, doname));
         }
@@ -3129,7 +3129,7 @@ muse_unslime(
         vis |= canseemon(mon); /* burning potion may improve visibility */
         if (vis) {
             if (!Unaware)
-                obj->dknown = 1; /* hero is watching mon drink obj */
+                observe_object(obj); /* hero is watching mon drink obj */
             pline("%s quaffs a burning %s",
                   saw_lit ? upstart(strcpy(Pronoun, mhe(mon))) : Monnam(mon),
                   simpleonames(obj));

src/nhlobj.c

@@ -210,7 +210,7 @@ l_obj_objects_to_table(lua_State *L)
     nhl_add_table_entry_int(L, "name_known", o->oc_name_known);
     nhl_add_table_entry_int(L, "merge", o->oc_merge);
     nhl_add_table_entry_int(L, "uses_known", o->oc_uses_known);
-    nhl_add_table_entry_int(L, "pre_discovered", o->oc_pre_discovered);
+    nhl_add_table_entry_int(L, "encountered", o->oc_encountered);
     nhl_add_table_entry_int(L, "magic", o->oc_magic);
     nhl_add_table_entry_int(L, "charged", o->oc_charged);
     nhl_add_table_entry_int(L, "unique", o->oc_unique);

src/o_init.c

@@ -377,7 +377,7 @@ savenames(NHFILE *nhfp)
     unsigned int len;
 
     if (update_file(nhfp)) {
-        for (i = 0; i < (MAXOCLASSES + 2); ++i) { 
+        for (i = 0; i < (MAXOCLASSES + 2); ++i) {
             Sfo_int(nhfp, &svb.bases[i], "names-bases");
         }
         for (i = 0; i < NUM_OBJECTS; ++i) {
@@ -436,41 +436,50 @@ restnames(NHFILE *nhfp)
 }
 
 #ifndef SFCTOOL
+/* make the object dknown and mark it as encountered */
+void
+observe_object(struct obj *obj)
+{
+    obj->dknown = 1;
+    discover_object(obj->otyp, FALSE, TRUE, FALSE);
+}
+
 void
 discover_object(
     int oindx,
     boolean mark_as_known,
+    boolean mark_as_encountered,
     boolean credit_hero)
 {
-    if (!objects[oindx].oc_name_known
+    if ((!objects[oindx].oc_name_known && mark_as_known)
+        || (!objects[oindx].oc_encountered && mark_as_encountered)
         || (Role_if(PM_SAMURAI)
             && Japanese_item_name(oindx, (const char *) 0))) {
         int dindx, acls = objects[oindx].oc_class;
 
         /* Loop thru disco[] 'til we find the target (which may have been
            uname'd) or the next open slot; one or the other will be found
-           before we reach the next class...
+           before we reach the next class... */
-         */
         for (dindx = svb.bases[acls]; svd.disco[dindx] != 0; dindx++)
             if (svd.disco[dindx] == oindx)
                 break;
         svd.disco[dindx] = oindx;
 
-        /* if already known, we forced an item with a Japanese name into
+        if (mark_as_encountered)
-           disco[] but don't want to exercise wisdom or update perminv */
+            objects[oindx].oc_encountered = 1;
-        if (objects[oindx].oc_name_known)
-            return;
 
-        if (mark_as_known) {
+        if (!objects[oindx].oc_name_known && mark_as_known) {
             objects[oindx].oc_name_known = 1;
             if (credit_hero)
                 exercise(A_WIS, TRUE);
-        }
+
-        /* !in_moveloop => initial inventory, gameover => final disclosure */
+            /* !in_moveloop => initial inventory,
-        if (program_state.in_moveloop && !program_state.gameover) {
+               gameover => final disclosure */
-            if (objects[oindx].oc_class == GEM_CLASS)
+            if (program_state.in_moveloop && !program_state.gameover) {
-                gem_learned(oindx); /* could affect price of unpaid gems */
+                if (objects[oindx].oc_class == GEM_CLASS)
-            update_inventory();
+                    gem_learned(oindx); /* could affect price of unpaid gems */
+                update_inventory();
+            }
         }
     }
 }
@@ -514,9 +523,11 @@ interesting_to_discover(int i)
     if (Role_if(PM_SAMURAI) && Japanese_item_name(i, (const char *) 0))
         return TRUE;
 
-    /* Pre-discovered objects are now printed with a '*' */
+    /* Objects that were discovered without encountering them are now printed
+       with a '*' */
     return (boolean) (objects[i].oc_uname != (char *) 0
-                      || (objects[i].oc_name_known
+                      || ((objects[i].oc_name_known
+                           || objects[i].oc_encountered)
                           && OBJ_DESCR(objects[i]) != (char *) 0));
 }
 
@@ -550,7 +561,7 @@ sortloot_descr(int otyp, char *outbuf)
     o = cg.zeroobj;
     o.otyp = otyp;
     o.oclass = objects[otyp].oc_class;
-    o.dknown = 1;
+    o.dknown = 1; /* not observe_object, this isn't a real object */
     o.known = (objects[otyp].oc_name_known || !objects[otyp].oc_uses_known)
               ? 1 : 0;
     o.corpsenm = NON_PM; /* suppress statue and figurine details */
@@ -784,7 +795,7 @@ dodiscovered(void) /* free after Robert Viduya */
                         prev_class = oclass;
                     }
                 }
-                Strcpy(buf,  objects[dis].oc_pre_discovered ? "* " : "  ");
+                Strcpy(buf, objects[dis].oc_encountered ? "  " : "* ");
                 if (lootsort)
                     (void) sortloot_descr(dis, &buf[2]);
                 disco_append_typename(buf, dis);
@@ -1011,7 +1022,7 @@ doclassdisco(void)
              ++i) {
             if ((dis = svd.disco[i]) != 0 && interesting_to_discover(dis)) {
                 ++ct;
-                Strcpy(buf,  objects[dis].oc_pre_discovered ? "* " : "  ");
+                Strcpy(buf, objects[dis].oc_encountered ? "  " : "* ");
                 if (lootsort)
                     (void) sortloot_descr(dis, &buf[2]);
                 disco_append_typename(buf, dis);
@@ -1113,7 +1124,7 @@ rename_disco(void)
             odummy.oclass = objects[dis].oc_class;
             odummy.quan = 1L;
             odummy.known = !objects[dis].oc_uses_known;
-            odummy.dknown = 1;
+            odummy.dknown = 1; /* not observe_object: it isn't real */
             docall(&odummy);
         }
     }

src/objnam.c

@@ -625,7 +625,7 @@ xname_flags(
     if (!nn && ocl->oc_uses_known && ocl->oc_unique)
         obj->known = 0;
     if (!Blind && !gd.distantname)
-        obj->dknown = 1;
+        observe_object(obj);
     if (Role_if(PM_CLERIC))
         obj->bknown = 1; /* avoid set_bknown() to bypass update_inventory() */
 
@@ -1057,6 +1057,8 @@ minimal_xname(struct obj *obj)
     bareobj = cg.zeroobj;
     bareobj.otyp = otyp;
     bareobj.oclass = obj->oclass;
+    /* not observe_object, either the hero observed the object already or this
+       is overriding ID and shouldn't discover the object */
     bareobj.dknown = (obj->dknown || iflags.override_ID) ? 1 : 0;
     /* suppress known except for amulets (needed for fakes and real A-of-Y) */
     bareobj.known = (obj->oclass == AMULET_CLASS)
@@ -1945,7 +1947,8 @@ killer_xname(struct obj *obj)
         save_oname = ONAME(obj);
 
     /* killer name should be more specific than general xname; however, exact
-       info like blessed/cursed and rustproof makes things be too verbose */
+       info like blessed/cursed and rustproof makes things be too verbose; set
+       dknown (not observe_object) because dead characters don't observe */
     obj->known = obj->dknown = 1;
     obj->bknown = obj->rknown = obj->greased = 0;
     /* if character is a priest[ess], bknown will get toggled back on */

src/pager.c

@@ -366,11 +366,11 @@ object_from_map(
         && (fakeobj || otmp->where == OBJ_FLOOR) /* not buried */
         /* terrain mode views what's already known, doesn't learn new stuff */
         && !iflags.terrainmode) /* so don't set dknown when in terrain mode */
-        otmp->dknown = 1; /* if a pile, clearly see the top item only */
+        observe_object(otmp); /* if a pile, clearly see the top item only */
     if (fakeobj && mtmp && mimic_obj
         && (otmp->dknown || (M_AP_FLAG(mtmp) & M_AP_F_DKNOWN))) {
         mtmp->m_ap_type |= M_AP_F_DKNOWN;
-        otmp->dknown = 1;
+        observe_object(otmp);
     }
     *obj_p = otmp;
     return fakeobj; /* when True, caller needs to dealloc *obj_p */

src/pickup.c

@@ -1816,7 +1816,7 @@ pickup_object(
     /* In case of auto-pickup, where we haven't had a chance
        to look at it yet; affects docall(SCR_SCARE_MONSTER). */
     if (!Blind)
-        obj->dknown = 1;
+        observe_object(obj);
 
     if (obj == uchain) { /* do not pick up attached chain */
         return 0;

src/polyself.c

@@ -646,7 +646,7 @@ polyself(int psflags)
                        re-converting scales to mail poses risk
                        of evaporation due to over enchanting */
                     uarm->otyp += GRAY_DRAGON_SCALES - GRAY_DRAGON_SCALE_MAIL;
-                    uarm->dknown = 1;
+                    observe_object(uarm);
                     disp.botl = TRUE; /* AC is changing */
                 }
                 uskin = uarm;
@@ -1371,7 +1371,7 @@ rehumanize(void)
             return; /* don't rehumanize after all */
         } else if (uamul && uamul->otyp == AMULET_OF_UNCHANGING) {
             Your("%s %s!", simpleonames(uamul), otense(uamul, "fail"));
-            uamul->dknown = 1;
+            observe_object(uamul);
             makeknown(AMULET_OF_UNCHANGING);
         }
     }

src/potion.c

@@ -2733,10 +2733,10 @@ potion_dip(struct obj *obj, struct obj *potion)
         else
             singlepotion->cursed = obj->cursed; /* odiluted left as-is */
         singlepotion->bknown = FALSE;
-        if (Blind) {
+        singlepotion->dknown = FALSE; /* provisionally */
-            singlepotion->dknown = FALSE;
+        if (!Blind) {
-        } else {
+            if (!Hallucination)
-            singlepotion->dknown = !Hallucination;
+                observe_object(singlepotion);
             *newbuf = '\0';
             if (mixture == POT_WATER && singlepotion->dknown)
                 Sprintf(newbuf, "clears");
@@ -2756,7 +2756,7 @@ potion_dip(struct obj *obj, struct obj *potion)
                 struct obj fakeobj;
 
                 fakeobj = cg.zeroobj;
-                fakeobj.dknown = 1;
+                fakeobj.dknown = 1; /* no need to observe_object */
                 fakeobj.otyp = old_otyp;
                 fakeobj.oclass = POTION_CLASS;
                 docall(&fakeobj);

src/pray.c

@@ -879,7 +879,7 @@ gcrownu(void)
                                          * even if hero doesn't know book */
         bless(obj);
         obj->bknown = 1; /* ok to skip set_bknown() */
-        obj->dknown = 1;
+        observe_object(obj);
         at_your_feet(upstart(ansimpleoname(obj)));
         dropy(obj);
         u.ugifts++;
@@ -923,7 +923,7 @@ gcrownu(void)
             ; /* already got bonus above */
         } else if (obj && in_hand) {
             Your("%s goes snicker-snack!", xname(obj));
-            obj->dknown = 1;
+            observe_object(obj);
         } else if (!already_exists) {
             obj = mksobj(LONG_SWORD, FALSE, FALSE);
             obj = oname(obj, artiname(ART_VORPAL_BLADE),
@@ -949,7 +949,7 @@ gcrownu(void)
             ; /* already got bonus above */
         } else if (obj && in_hand) {
             Your("%s hums ominously!", swordbuf);
-            obj->dknown = 1;
+            observe_object(obj);
         } else if (!already_exists) {
             obj = mksobj(RUNESWORD, FALSE, FALSE);
             obj = oname(obj, artiname(ART_STORMBRINGER),
@@ -1052,7 +1052,8 @@ give_spell(void)
         }
         obfree(otmp, (struct obj *) 0); /* discard the book */
     } else {
-        otmp->dknown = 1; /* not bknown */
+        observe_object(otmp);
+        /* don't set bknown */
         /* discovering blank paper will make it less likely to
            be given again; small chance to arbitrarily discover
            some other book type without having to read it first */
@@ -1824,7 +1825,7 @@ bestow_artifact(uchar max_giftvalue)
             /* make sure we can use this weapon */
             unrestrict_weapon_skill(weapon_type(otmp));
             if (!Hallucination && !Blind) {
-                otmp->dknown = 1;
+                observe_object(otmp);
                 makeknown(otmp->otyp);
                 discover_artifact(otmp->oartifact);
             }

src/quest.c

@@ -127,7 +127,7 @@ artitouch(struct obj *obj)
     if (!Qstat(touched_artifact)) {
         /* in case we haven't seen the item yet (ie, currently blinded),
            this quest message describes it by name so mark it as seen */
-        obj->dknown = 1;
+        observe_object(obj);
         /* only give this message once */
         Qstat(touched_artifact) = TRUE;
         qt_pager("gotit");

src/shk.c

@@ -3360,7 +3360,7 @@ shk_names_obj(
     char *obj_name, fmtbuf[BUFSZ];
     boolean was_unknown = !obj->dknown;
 
-    obj->dknown = TRUE;
+    observe_object(obj);
     /* Use real name for ordinary weapons/armor, and spell-less
      * scrolls/books (that is, blank and mail), but only if the
      * object is within the shk's area of interest/expertise.

src/sit.c

@@ -371,7 +371,8 @@ lay_an_egg(void)
     uegg->owt = weight(uegg);
     /* this sets hatch timers if appropriate */
     set_corpsenm(uegg, egg_type_from_parent(u.umonnum, FALSE));
-    uegg->known = uegg->dknown = 1;
+    uegg->known = 1;
+    observe_object(uegg);
     You("%s an egg.", eggs_in_water(gy.youmonst.data) ? "spawn" : "lay");
     dropy(uegg);
     stackobj(uegg);

src/spell.c

@@ -234,7 +234,7 @@ deadbook(struct obj *book2)
 
     You("turn the pages of the Book of the Dead...");
     makeknown(SPE_BOOK_OF_THE_DEAD);
-    book2->dknown = 1; /* in case blind now and hasn't been seen yet */
+    observe_object(book2); /* in case blind now and hasn't been seen yet */
     /* KMH -- Need ->known to avoid "_a_ Book of the Dead" */
     book2->known = 1;
     if (invocation_pos(u.ux, u.uy) && !On_stairs(u.ux, u.uy)) {
@@ -896,8 +896,9 @@ skill_based_spellbook_id(void)
         }
 
         if (objects[booktype].oc_level <= known_up_to_level)
-            /* makeknown(booktype) but don't exercise Wisdom */
+            /* makeknown(booktype) but don't exercise Wisdom or mark as
-            discover_object(booktype, TRUE, FALSE);
+               encountered */
+            discover_object(booktype, TRUE, FALSE, FALSE);
     }
 }
 

src/trap.c

@@ -1206,7 +1206,7 @@ trapeffect_arrow_trap(
         } else {
             place_object(otmp, u.ux, u.uy);
             if (!Blind)
-                otmp->dknown = 1;
+                observe_object(otmp);
             stackobj(otmp);
             newsym(u.ux, u.uy);
         }
@@ -1276,7 +1276,7 @@ trapeffect_dart_trap(
         } else {
             place_object(otmp, u.ux, u.uy);
             if (!Blind)
-                otmp->dknown = 1;
+                observe_object(otmp);
             stackobj(otmp);
             newsym(u.ux, u.uy);
         }
@@ -1352,7 +1352,7 @@ trapeffect_rocktrap(
                 harmless = TRUE;
             }
             if (!Blind)
-                otmp->dknown = 1;
+                observe_object(otmp);
             stackobj(otmp);
             newsym(u.ux, u.uy); /* map the rock */
 
@@ -5738,7 +5738,7 @@ untrap_box(
         else
             pline("There's a trap on %s.", the(xname(box)));
         box->tknown = 1;
-        box->dknown = 1;
+        observe_object(box);
         if (!confused)
             exercise(A_WIS, TRUE);
 

src/u_init.c

@@ -562,8 +562,8 @@ knows_object(int obj, boolean override_pauper)
 {
     if (u.uroleplay.pauper && !override_pauper)
         return;
-    discover_object(obj, TRUE, FALSE);
+    /* mark as known, but not yet encountered */
-    objects[obj].oc_pre_discovered = 1; /* not a "discovery" */
+    discover_object(obj, TRUE, FALSE, FALSE);
 }
 
 /* Know ordinary (non-magical) objects of a certain class,
@@ -1207,6 +1207,7 @@ ini_inv_adjust_obj(struct trobj *trop, struct obj *obj)
     } else {
         if (objects[obj->otyp].oc_uses_known)
             obj->known = 1;
+        /* not observe_object during startup, that's handled later */
         obj->dknown = obj->bknown = obj->rknown = 1;
         if (Is_container(obj) || obj->otyp == STATUE) {
             obj->cknown = obj->lknown = 1;
@@ -1246,9 +1247,9 @@ ini_inv_use_obj(struct obj *obj)
 {
     /* Make the type known if necessary */
     if (OBJ_DESCR(objects[obj->otyp]) && obj->known)
-        discover_object(obj->otyp, TRUE, FALSE);
+        discover_object(obj->otyp, TRUE, TRUE, FALSE);
     if (obj->otyp == OIL_LAMP)
-        discover_object(POT_OIL, TRUE, FALSE);
+        discover_object(POT_OIL, TRUE, TRUE, FALSE);
 
     if (obj->oclass == ARMOR_CLASS) {
         if (is_shield(obj) && !uarms && !(uwep && bimanual(uwep))) {

src/uhitm.c

@@ -1133,7 +1133,7 @@ hmon_hitmon_misc_obj(
                 corpse_xname(obj, (const char *) 0,
                              obj->dknown ? CXN_PFX_THE
                              : CXN_ARTICLE));
-            obj->dknown = 1;
+            observe_object(obj);
             if (!munstone(mon, TRUE))
                 minstapetrify(mon, TRUE);
             if (resists_ston(mon))

src/write.c

@@ -143,7 +143,7 @@ dowrite(struct obj *pen)
             return ECMD_OK;
         }
     }
-    paper->dknown = 1;
+    observe_object(paper);
     if (paper->otyp != SCR_BLANK_PAPER && paper->otyp != SPE_BLANK_PAPER) {
         pline("That %s is not blank!", typeword);
         exercise(A_WIS, FALSE);
@@ -326,13 +326,8 @@ dowrite(struct obj *pen)
      *
      * Writing by description requires that the hero knows the
      * description (a scroll's label, that is, since books by_descr
-     * are rejected above).  BUG:  We can only do this for known
+     * are rejected above).  This is done by checking to see if a
-     * scrolls and for the case where the player has assigned a
+     * scroll with the same description has been encountered.
-     * name to put it onto the discoveries list; we lack a way to
-     * track other scrolls which have been seen closely enough to
-     * read the label without then being ID'd or named.  The only
-     * exception is for currently carried inventory, where we can
-     * check for one [with its dknown bit set] of the same type.
      *
      * Normal requirements can be overridden if hero is Lucky.
      */
@@ -345,7 +340,7 @@ dowrite(struct obj *pen)
     /* if known, then either by-name or by-descr works */
     if (!objects[new_obj->otyp].oc_name_known
         /* else if named, then only by-descr works */
-        && !(by_descr && label_known(new_obj->otyp, gi.invent))
+        && !(by_descr && objects[new_obj->otyp].oc_encountered)
         /* else fresh knowledge of the spell works */
         && spell_knowledge != spe_Fresh
         /* and Luck might override after previous checks have failed */

src/zap.c

@@ -132,14 +132,14 @@ learnwand(struct obj *obj)
         /* if type already discovered, treat this item has having been seen
            even if hero is currently blinded (skips redundant makeknown) */
         if (objects[obj->otyp].oc_name_known) {
-            obj->dknown = 1; /* will usually be set already */
+            observe_object(obj); /* will usually be dknown already */
 
         /* otherwise discover it if item itself has been or can be seen */
         } else {
             /* in case it was picked up while blind and then zapped without
                examining inventory after regaining sight (bypassing xname) */
             if (!Blind)
-                obj->dknown = 1;
+                observe_object(obj);
             /* make the discovery iff we know what we're manipulating */
             if (obj->dknown)
                 makeknown(obj->otyp);
@@ -610,7 +610,7 @@ staticfn void
 probe_objchain(struct obj *otmp)
 {
     for (; otmp; otmp = otmp->nobj) {
-        otmp->dknown = 1; /* treat as "seen" */
+        observe_object(otmp); /* treat as "seen" */
         if (Is_container(otmp) || otmp->otyp == STATUE) {
             otmp->lknown = 1;
             if (!SchroedingersBox(otmp))
@@ -2220,7 +2220,7 @@ bhito(struct obj *obj, struct obj *otmp)
         case WAN_PROBING:
             res = !obj->dknown;
             /* target object has now been "seen (up close)" */
-            obj->dknown = 1;
+            observe_object(obj);
             if (Is_container(obj) || obj->otyp == STATUE) {
                 obj->cknown = obj->lknown = 1;
                 if (Is_box(obj) && !obj->tknown) {
@@ -2249,7 +2249,7 @@ bhito(struct obj *obj, struct obj *otmp)
 
                     /* view contents (not recursively) */
                     for (o = obj->cobj; o; o = o->nobj)
-                        o->dknown = 1; /* "seen", even if blind */
+                        observe_object(o); /* "seen", even if blind */
                     (void) display_cinventory(obj);
                 }
                 res = 1;