Fix: rknown ID of glass armor, other item classes

not_fully_identified wasn't updated to account for the fact that glass
items, nontraditional classes like scrolls and rings, and various other
previously-impossible targets can now be fooproofed with confused
enchant weapon.  Make sure the function is updated to reflect the types
of items where rknown matters, so that you can formally learn their
oerodeproof status.

src/objnam.c

@@ -1449,19 +1449,13 @@ not_fully_identified(struct obj* otmp)
     if (otmp->oartifact && undiscovered_artifact(otmp->oartifact))
         return TRUE;
     /* otmp->rknown is the only item of interest if we reach here */
-    /*
-     *  Note:  if a revision ever allows scrolls to become fireproof or
-     *  rings to become shockproof, this checking will need to be revised.
-     *  `rknown' ID only matters if xname() will provide the info about it.
-     */
     if (otmp->rknown
-        || (otmp->oclass != ARMOR_CLASS && otmp->oclass != WEAPON_CLASS
-            && !is_weptool(otmp)            /* (redundant) */
-            && otmp->oclass != BALL_CLASS)) /* (useless) */
+        || (!erosion_matters(otmp) && !destroyable_oclass(otmp->oclass)))
         return FALSE;
     else /* lack of `rknown' only matters for vulnerable objects */
-        return (boolean) (is_rustprone(otmp) || is_corrodeable(otmp)
-                          || is_flammable(otmp));
+        return (boolean) (is_damageable(otmp)
+                          || destroyable_oclass(otmp->oclass)
+                          || otmp->material == GLASS);
 }
 
 /* format a corpse name (xname() omits monster type; doname() calls us);