bill_dummy_object

     Various actions (potion dilution, igniting candles or oil, dulling a
weapon by engraving) on an unpaid object can modify it in such a way that
a shopkeeper will force the hero to buy it.  bill_dummy_object() is used
to make a copy for the shop bill; play continues with the modified item
now owned by the player.  bill_dummy_object() was setting the no_charge
flag unconditionally on the modified object but the flag shouldn't be set
for items in inventory.  It was possible to drop the object and sell it,
pick it back up for free due to that flag setting, then drop it and sell
it again.  One easy way to reproduce is to zap yourself with a wand of
cancellation while carrying unpaid positively enchanted armor or weapon.

     The no_charge flag gets cleared when you pick something up off the
floor or take it out of a container, so this sell-it-again case would only
repeat once.  Selling a dropped item ought to clear the flag, but my head
is still spinning after looking at the shop code to see about implementing
that.  This fix just prevents bill_dummy_object() from mis-setting the
flag in the first place; sellobj() still can't fix it up after the fact.

diff --git a/doc/fixes34.4 b/doc/fixes34.4
index 20b7955239af47c2569e49f9259e8a5f16342dae..5b188749fc24367e3ce69d73dc503ca7272ecc7a 100644 (file)
--- a/doc/fixes34.4
+++ b/doc/fixes34.4
@@ -106,6 +106,7 @@ fix various places that "finally finished" could be displayed after the hero
        stopped doing something other than eating
 fix some cases where movement was disallowed but the hero was still conscious
 after destroying drawbridge, hero could appear to be in the wall
+sometimes shop items which hero is forced to buy could be sold back twice
 
 
 Platform- and/or Interface-Specific Fixes

diff --git a/src/mkobj.c b/src/mkobj.c
index 619c8ba0219766222d9b087c881a40510ef0e39f..35fd7bccb2767b88c585d51ffa13fc6e028f145b 100644 (file)
--- a/src/mkobj.c
+++ b/src/mkobj.c
@@ -1,4 +1,4 @@
-/*     SCCS Id: @(#)mkobj.c    3.5     2002/10/07      */
+/*     SCCS Id: @(#)mkobj.c    3.5     2005/03/26      */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -342,7 +342,9 @@ register struct obj *otmp;
            (void)strncpy(ONAME(dummy), ONAME(otmp), (int)otmp->onamelth);
        if (Is_candle(dummy)) dummy->lamplit = 0;
        addtobill(dummy, FALSE, TRUE, TRUE);
-       otmp->no_charge = 1;
+       /* no_charge is only valid for some locations */
+       otmp->no_charge = (otmp->where == OBJ_FLOOR ||
+                          otmp->where == OBJ_CONTAINED) ? 1 : 0;
        otmp->unpaid = 0;
        return;
 }