Return 0 as mob GID if mob not really usable for script.return-summon-gid

Testing shown it can happen if e.g. mob placed on collision on spawn.
Somehow internal function would return some block ID anyway. However e.g.
(mob->hp == 0) gives this case away.

1 files changed, 10 insertions, 3 deletions

diff --git a/src/map/script-fun.cpp b/src/map/script-fun.cpp
index 5982624..1a292b9 100644
--- a/src/map/script-fun.cpp
+++ b/src/map/script-fun.cpp
@@ -3111,8 +3111,6 @@ void builtin_summon(ScriptState *st)
     if (mob)
     {
         mob->mode = get_mob_db(monster_id).mode;
-        push_int<ScriptDataInt>(st->stack, unwrap<BlockId>(mob->bl_id)); // Return mob GID to caller
-
         switch (monster_attitude)
         {
             case MonsterAttitude::SERVANT:
@@ -3150,8 +3148,17 @@ void builtin_summon(ScriptState *st)
             mob->master_id = owner->bl_id;
             mob->master_dist = 6;
         }
+
+        if (mob->hp > 0) // Is mob REALLY spawned && usable?
+        {
+            push_int<ScriptDataInt>(st->stack, unwrap<BlockId>(mob->bl_id)); // Return mob GID to caller
+        }
+        else // Server can fail to place mob (e.g. collision) but ->bl_id still valid?
+        {    // (md->hp == 0) gives this case away.
+            push_int<ScriptDataInt>(st->stack, 0);
+        }
     }
-    else // got no (mob), default
+    else // got no (mob), report failure to caller
     {
         push_int<ScriptDataInt>(st->stack, 0);
     }