Fixed MONS_NO_MONSTER == NUM_MONSTERS + 1

Fixed MONS_NO_MONSTER == NUM_MONSTERS + 1, which was a problem because
MONS_NO_MONSTER can end up in savefiles, meaning that when NUM_MONSTERS
increased old save files would become broken.

unmarshall_monster() has a temporary hack to preserve compatibility with
old save files, and will fail a COMPILE_CHECK() when NUM_MONSTERS
increases beyond its current value.

1 files changed, 10 insertions, 0 deletions

diff --git a/crawl-ref/source/tags.cc b/crawl-ref/source/tags.cc
index 04e6102d32..9300e7329b 100644
--- a/crawl-ref/source/tags.cc
+++ b/crawl-ref/source/tags.cc
@@ -2217,6 +2217,16 @@ static void unmarshall_monster(reader &th, monsters &m)
         m.set_ghost(unmarshallGhost(th, _tag_minor_version));
 
     m.check_speed();
+
+    // XXX: Changed MONS_NO_MONSTER from NUM_MONSTERS + 1 to 1000.
+    // This is a temporary hack, remove when the following compile
+    // time assert fails.
+    COMPILE_CHECK(NUM_MONSTERS == 472, c1);
+
+    if (m.type == (NUM_MONSTERS + 1))
+        m.type = MONS_NO_MONSTER;
+    if (m.base_monster == (NUM_MONSTERS + 1))
+        m.base_monster = MONS_NO_MONSTER;
 }
 
 static void tag_read_level_monsters(reader &th, char minorVersion)