tin identification

Tin handling code used tin->cknown to indicate that the variety
(soup, deep fried, pureed, &c) was known, but neither object
identification nor end of game disclosure was setting cknown for
that type of object.

^I behaves as if cknown is set, so the problem was hidden during
times when anyone was likely to be paying attention.

doc/fixes37.0

@@ -1,4 +1,4 @@
-NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.262 $ $NHDT-Date: 1596162338 2020/07/31 02:25:38 $
+NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.264 $ $NHDT-Date: 1596226446 2020/07/31 20:14:06 $
 
 General Fixes and Modified Features
 -----------------------------------
@@ -236,6 +236,8 @@ uncancel an ice troll if its corpse is put into an ice box; give corpse a
 splitting a stack of candy bars gave new wrapper text depending upon the
 	obj->o_id value assigned; keep existing text for both halves of stack
 	(side-effect: separate candy bars usually won't merge anymore)
+describing tin variety (deep fried, pureed, &c) relied on the 'contents known'
+	flag but object identification wasn't setting obj->cknown for tins
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository

include/extern.h

@@ -1,4 +1,4 @@
-/* NetHack 3.6	extern.h	$NHDT-Date: 1596162339 2020/07/31 02:25:39 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.852 $ */
+/* NetHack 3.6	extern.h	$NHDT-Date: 1596226441 2020/07/31 20:14:01 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.853 $ */
 /* Copyright (c) Steve Creps, 1988.				  */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -1044,6 +1044,7 @@ E int FDECL(ggetobj, (const char *, int (*)(OBJ_P), int,
                       BOOLEAN_P, unsigned *));
 E int FDECL(askchain, (struct obj **, const char *, int, int (*)(OBJ_P),
                        int (*)(OBJ_P), int, const char *));
+E void FDECL(set_cknown_lknown, (struct obj *));
 E void FDECL(fully_identify_obj, (struct obj *));
 E int FDECL(identify, (struct obj *));
 E int FDECL(count_unidentified, (struct obj *));

include/obj.h

@@ -1,4 +1,4 @@
-/* NetHack 3.6	obj.h	$NHDT-Date: 1596162340 2020/07/31 02:25:40 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.70 $ */
+/* NetHack 3.6	obj.h	$NHDT-Date: 1596226442 2020/07/31 20:14:02 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.75 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Michael Allison, 2006. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -106,7 +106,8 @@ struct obj {
 
     Bitfield(in_use, 1); /* for magic items before useup items */
     Bitfield(bypass, 1); /* mark this as an object to be skipped by bhito() */
-    Bitfield(cknown, 1); /* contents of container assumed to be known */
+    Bitfield(cknown, 1); /* for containers (including statues): the contents
+                          * are known; also applicable to tins */
     Bitfield(lknown, 1); /* locked/unlocked status is known */
     /* 4 free bits */
 

src/end.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	end.c	$NHDT-Date: 1583190253 2020/03/02 23:04:13 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.208 $ */
+/* NetHack 3.6	end.c	$NHDT-Date: 1596226442 2020/07/31 20:14:02 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.210 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2012. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -1315,8 +1315,7 @@ int how;
         for (obj = g.invent; obj; obj = obj->nobj) {
             discover_object(obj->otyp, TRUE, FALSE);
             obj->known = obj->bknown = obj->dknown = obj->rknown = 1;
-            if (Is_container(obj) || obj->otyp == STATUE)
+            set_cknown_lknown(obj); /* set flags when applicable */
-                obj->cknown = obj->lknown = 1;
             /* we resolve Schroedinger's cat now in case of both
                disclosure and dumplog, where the 50:50 chance for
                live cat has to be the same both times */

src/invent.c

@@ -1,4 +1,4 @@
-/* NetHack 3.7	invent.c	$NHDT-Date: 1590343765 2020/05/24 18:09:25 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.299 $ */
+/* NetHack 3.7	invent.c	$NHDT-Date: 1596226443 2020/07/31 20:14:03 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.300 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Derek S. Ray, 2015. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -2315,6 +2315,20 @@ int FDECL((*fn), (OBJ_P)), FDECL((*ckfn), (OBJ_P));
  *      Object identification routines:
  */
 
+/* set the cknown and lknown flags on an object if they're applicable */
+void
+set_cknown_lknown(obj)
+struct obj *obj;
+{
+    if (Is_container(obj) || obj->otyp == STATUE)
+        obj->cknown = obj->lknown = 1;
+    else if (obj->otyp == TIN)
+        obj->cknown = 1;
+    /* TODO? cknown might be extended to candy bar, where it would mean that
+       wrapper's text was known which in turn indicates candy bar's content */
+    return;
+}
+
 /* make an object actually be identified; no display updating */
 void
 fully_identify_obj(otmp)
@@ -2324,8 +2338,7 @@ struct obj *otmp;
     if (otmp->oartifact)
         discover_artifact((xchar) otmp->oartifact);
     otmp->known = otmp->dknown = otmp->bknown = otmp->rknown = 1;
-    if (Is_container(otmp) || otmp->otyp == STATUE)
+    set_cknown_lknown(otmp); /* set otmp->{cknown,lknown} if applicable */
-        otmp->cknown = otmp->lknown = 1;
     if (otmp->otyp == EGG && otmp->corpsenm != NON_PM)
         learn_egg_type(otmp->corpsenm);
 }