From 57584a22d7eb05adcde0422252d56f350d73019c Mon Sep 17 00:00:00 2001
From: nhmall <nhmall@nethack.org>
Date: Sun, 17 Nov 2019 19:13:23 -0500
Subject: [PATCH] add some guard code to the Is_*_level macros in dungeon.h

All Is_*_level tests during early startup would test as true until
dungeon_topology was initialized in a new game or restored from
a save file. That could result in some unexpected code paths being
taken.
---
 doc/fixes36.3     |  3 +++
 include/dungeon.h | 55 ++++++++++++++++++++++++++---------------------
 2 files changed, 33 insertions(+), 25 deletions(-)

diff --git a/doc/fixes36.3 b/doc/fixes36.3
index 1b2caaebf..16ab5de31 100644
--- a/doc/fixes36.3
+++ b/doc/fixes36.3
@@ -235,6 +235,9 @@ dipping lichen corpse into acid when not blind and acid was undicovered would
 pluralization improvement for words ending in a k-sound like "biotech"
 check for whether a monster was entering a region (gas cloud) erroneously
 	depended upon whether or not the hero was inside the same region
+all Is_*_level tests during early startup would test as true until
+	dungeon_topology was initialized in a new game or restored from 
+	a save file
 
 
 Fixes to Post-3.6.2 Problems that Were Exposed Via git Repository
diff --git a/include/dungeon.h b/include/dungeon.h
index 45246f150..1d476ff7a 100644
--- a/include/dungeon.h
+++ b/include/dungeon.h
@@ -98,31 +98,36 @@ typedef struct branch {
  *
  * Depth corresponds to the number of floors below the surface.
  */
-#define Is_astralevel(x) (on_level(x, &astral_level))
-#define Is_earthlevel(x) (on_level(x, &earth_level))
-#define Is_waterlevel(x) (on_level(x, &water_level))
-#define Is_firelevel(x) (on_level(x, &fire_level))
-#define Is_airlevel(x) (on_level(x, &air_level))
-#define Is_medusa_level(x) (on_level(x, &medusa_level))
-#define Is_oracle_level(x) (on_level(x, &oracle_level))
-#define Is_valley(x) (on_level(x, &valley_level))
-#define Is_juiblex_level(x) (on_level(x, &juiblex_level))
-#define Is_asmo_level(x) (on_level(x, &asmodeus_level))
-#define Is_baal_level(x) (on_level(x, &baalzebub_level))
-#define Is_wiz1_level(x) (on_level(x, &wiz1_level))
-#define Is_wiz2_level(x) (on_level(x, &wiz2_level))
-#define Is_wiz3_level(x) (on_level(x, &wiz3_level))
-#define Is_sanctum(x) (on_level(x, &sanctum_level))
-#define Is_portal_level(x) (on_level(x, &portal_level))
-#define Is_rogue_level(x) (on_level(x, &rogue_level))
-#define Is_stronghold(x) (on_level(x, &stronghold_level))
-#define Is_bigroom(x) (on_level(x, &bigroom_level))
-#define Is_qstart(x) (on_level(x, &qstart_level))
-#define Is_qlocate(x) (on_level(x, &qlocate_level))
-#define Is_nemesis(x) (on_level(x, &nemesis_level))
-#define Is_knox(x) (on_level(x, &knox_level))
-#define Is_mineend_level(x) (on_level(x, &mineend_level))
-#define Is_sokoend_level(x) (on_level(x, &sokoend_level))
+
+/* These both can't be zero, or dungeon_topology isn't init'd / restored */
+#define Lassigned(y) ((y)->dlevel || (y)->dnum)
+#define Lcheck(x,z) (Lassigned(z) && on_level(x, z))
+
+#define Is_astralevel(x)    (Lcheck(x, &astral_level))
+#define Is_earthlevel(x)    (Lcheck(x, &earth_level))
+#define Is_waterlevel(x)    (Lcheck(x, &water_level))
+#define Is_firelevel(x)     (Lcheck(x, &fire_level))
+#define Is_airlevel(x)      (Lcheck(x, &air_level))
+#define Is_medusa_level(x)  (Lcheck(x, &medusa_level))
+#define Is_oracle_level(x)  (Lcheck(x, &oracle_level))
+#define Is_valley(x)        (Lcheck(x, &valley_level))
+#define Is_juiblex_level(x) (Lcheck(x, &juiblex_level))
+#define Is_asmo_level(x)    (Lcheck(x, &asmodeus_level))
+#define Is_baal_level(x)    (Lcheck(x, &baalzebub_level))
+#define Is_wiz1_level(x)    (Lcheck(x, &wiz1_level))
+#define Is_wiz2_level(x)    (Lcheck(x, &wiz2_level))
+#define Is_wiz3_level(x)    (Lcheck(x, &wiz3_level))
+#define Is_sanctum(x)       (Lcheck(x, &sanctum_level))
+#define Is_portal_level(x)  (Lcheck(x, &portal_level))
+#define Is_rogue_level(x)   (Lcheck(x, &rogue_level))
+#define Is_stronghold(x)    (Lcheck(x, &stronghold_level))
+#define Is_bigroom(x)       (Lcheck(x, &bigroom_level))
+#define Is_qstart(x)        (Lcheck(x, &qstart_level))
+#define Is_qlocate(x)       (Lcheck(x, &qlocate_level))
+#define Is_nemesis(x)       (Lcheck(x, &nemesis_level))
+#define Is_knox(x)          (Lcheck(x, &knox_level))
+#define Is_mineend_level(x) (Lcheck(x, &mineend_level))
+#define Is_sokoend_level(x) (Lcheck(x, &sokoend_level))
 
 #define In_sokoban(x) ((x)->dnum == sokoban_dnum)
 #define Inhell In_hell(&u.uz) /* now gehennom */