ignitable() macro

ignitable() was excluding magic lamp and then every place that
used it did so as 'ignitable(obj) || obj->otyp == MAGIC_LAMP'
so just include magic lamp.

I noticed that while hunting for an explanation for report #K2734
where returning to a previously visited level triggered the
warning "begin_burn: unexpected eggs".  I've decided that the
zombie apocalypse is probably the cause.  It inserted a new type
of timer in the list of such but it didn't bump EDITLEVEL to
invalidate save and bones files which relied on indices into the
old list.  I'm not sure whether we should bump that now.

include/obj.h

@@ -1,4 +1,4 @@
-/* NetHack 3.7	obj.h	$NHDT-Date: 1596498552 2020/08/03 23:49:12 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.76 $ */
+/* NetHack 3.7	obj.h	$NHDT-Date: 1604442292 2020/11/03 22:24:52 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.78 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Michael Allison, 2006. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -308,22 +308,26 @@ struct obj {
     (otmp->otyp == TALLOW_CANDLE || otmp->otyp == WAX_CANDLE)
 #define MAX_OIL_IN_FLASK 400 /* maximum amount of oil in a potion of oil */
 
-/* MAGIC_LAMP intentionally excluded below */
+/* age field of this is relative age rather than absolute; does not include
-/* age field of this is relative age rather than absolute */
+   magic lamp */
-#define age_is_relative(otmp)                                       \
+#define age_is_relative(otmp) \
     ((otmp)->otyp == BRASS_LANTERN || (otmp)->otyp == OIL_LAMP      \
      || (otmp)->otyp == CANDELABRUM_OF_INVOCATION                   \
      || (otmp)->otyp == TALLOW_CANDLE || (otmp)->otyp == WAX_CANDLE \
      || (otmp)->otyp == POT_OIL)
-/* object can be ignited */
+/* object can be ignited; magic lamp used to excluded here too but all
-#define ignitable(otmp)                                             \
+   usage of this macro ended up testing
+     (ignitable(obj) || obj->otyp == MAGIC_LAMP)
+   so include it; brass lantern can be lit but not by fire */
+#define ignitable(otmp) \
     ((otmp)->otyp == BRASS_LANTERN || (otmp)->otyp == OIL_LAMP      \
+     || ((otmp)->otyp == MAGIC_LAMP && (otmp)->spe > 0)             \
      || (otmp)->otyp == CANDELABRUM_OF_INVOCATION                   \
      || (otmp)->otyp == TALLOW_CANDLE || (otmp)->otyp == WAX_CANDLE \
      || (otmp)->otyp == POT_OIL)
 
 /* things that can be read */
-#define is_readable(otmp)                                                    \
+#define is_readable(otmp) \
     ((otmp)->otyp == FORTUNE_COOKIE || (otmp)->otyp == T_SHIRT               \
      || (otmp)->otyp == ALCHEMY_SMOCK || (otmp)->otyp == CREDIT_CARD         \
      || (otmp)->otyp == CAN_OF_GREASE || (otmp)->otyp == MAGIC_MARKER        \

src/apply.c

@@ -1,4 +1,4 @@
-/* NetHack 3.7	apply.c	$NHDT-Date: 1602270122 2020/10/09 19:02:02 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.328 $ */
+/* NetHack 3.7	apply.c	$NHDT-Date: 1604442295 2020/11/03 22:24:55 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.330 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2012. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -1404,14 +1404,14 @@ struct obj *obj;
 }
 
 /* Called when potentially lightable object is affected by fire_damage().
-   Return TRUE if object was lit and FALSE otherwise --ALI */
+   Return TRUE if object becomes lit and FALSE otherwise --ALI */
 boolean
 catch_lit(obj)
 struct obj *obj;
 {
     xchar x, y;
 
-    if (!obj->lamplit && (obj->otyp == MAGIC_LAMP || ignitable(obj))) {
+    if (!obj->lamplit && ignitable(obj)) {
         if ((obj->otyp == MAGIC_LAMP
              || obj->otyp == CANDELABRUM_OF_INVOCATION) && obj->spe == 0)
             return FALSE;

src/light.c

@@ -1,4 +1,4 @@
-/* NetHack 3.7	light.c	$NHDT-Date: 1596498173 2020/08/03 23:42:53 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.45 $ */
+/* NetHack 3.7	light.c	$NHDT-Date: 1604442297 2020/11/03 22:24:57 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.46 $ */
 /* Copyright (c) Dean Luick, 1994                                       */
 /* NetHack may be freely redistributed.  See license for details.       */
 
@@ -691,8 +691,7 @@ boolean
 obj_is_burning(obj)
 struct obj *obj;
 {
-    return (boolean) (obj->lamplit && (obj->otyp == MAGIC_LAMP
+    return (boolean) (obj->lamplit && (ignitable(obj)
-                                       || ignitable(obj)
                                        || artifact_light(obj)));
 }
 

src/trap.c

@@ -1,4 +1,4 @@
-/* NetHack 3.7	trap.c	$NHDT-Date: 1602270123 2020/10/09 19:02:03 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.364 $ */
+/* NetHack 3.7	trap.c	$NHDT-Date: 1604442297 2020/11/03 22:24:57 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.365 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2013. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -5563,9 +5563,9 @@ boolean override;
     return defsyms[trap_to_defsym(ttyp)].explanation;
 }
 
-/* Ignite ignitable items in the given object chain, due to some external source
+/* Ignite ignitable items in the given object chain, due to some external
- * of fire. The object chain should be somewhere exposed, like someone's open
+ * source of fire.  The object chain should be somewhere exposed, like
- * inventory or the floor.
+ * someone's open inventory or the floor.
  * This is modeled after destroy_item() somewhat and hopefully will be able to
  * merge into it in the future.
  */
@@ -5590,7 +5590,7 @@ struct obj *objchn;
     }
 
     for (obj = objchn; obj; obj = obj->nobj) {
-        if (!(ignitable(obj) || obj->otyp == MAGIC_LAMP)
+        if (!ignitable(obj)
             /* The Candelabrum requires intention to be lit */
             || obj->otyp == CANDELABRUM_OF_INVOCATION
             || obj->otyp == BRASS_LANTERN /* doesn't ignite via fire */